View Full Version : Homemade 35mm Adapter


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Bob Hart
January 5th, 2006, 01:04 AM
Furthur info.

In some real world tests yesterday, in high contrast, low light conditions or late afternoon/early evening, there remained a slight brightness falloff on the left (rear prism) side of the image. Like with a fixed groundglass, the defect is not readily apparent until the camera is panned and the image travels across the frame.

I opened up the path a little more with only 0.25mm supprt remaining to the front prism edge and this seems to have helped. The centering of the front prism apex relative to the edge of the rear prism seems a lot more critical than I had thought. This also cleaned it up some more.

Bob Hart
January 5th, 2006, 10:27 PM
Furthur info.

What I thought was a doubler function on the FX1 which would work like the doubler on ENG cameras is actually a focussing aid only and does not record.

As a potential newscam, I thought this was an excellent feature. So I was wrong.

Bob Hart
January 6th, 2006, 07:45 AM
Furthur to previous posts, I have tried the Nikon SLR lens >> 5 micron dressed groundglass disk >> 40mm x 40mm x 56mm common thickness prism pair >> Century Optics 7+ achromatic dioptre >> combination, as adjusted for the Sony HDRFX1 into a Panasonic DVX100 (PAL) and it seems it should work fine.

The appliance was positioned in front of the camcorder by hand as there was no rear adaptor mount made. In the LCD screen there was a clean image however an underscanning monitor was not used, so what is outside of the TV safe area is not known. Lenses tested were Sigma 50 - 500mm F4 zoom and an older Nikon f2.8 zoom. There was no vignette with these so f1.8 prime lenses should be okay. The DVX100 is an early model with 4:3 CCDs.

PS - Does anyone know how to stop this wretched McAfee Instant Updater phoning home and freezing the screen all the time whilst on-line.?

Chris Hurd
January 6th, 2006, 08:55 AM
Sorry for the delay Bob, I will try to get those images up today.

Thanks for keeping this thread alive, it's the one which started this forum!

Bob Hart
January 6th, 2006, 09:33 AM
Chris.

Is no problem. If you can hold on them for a little longer, I've a few more to send which I shall do now.

Regards.

Bob Hart
January 8th, 2006, 06:16 AM
Here's some useless information regarding the AGUS35 - Australian Plumber's Version - Image Erector.

Compared to the SG35, Letus35, Redrock, etc, it is inefficently large because of the CD sized disk. Except for being dropped or run over, I expect it to last a long time as the only fast moving wearing parts are in the motor which runs at about 1500 rpm.

This version does not permit integration of rod style supports through to the camcorder as the disk enclosure gets in the way. The enclosure is also too large to move on top as it then touches parts of the camcorders.

It could be redesigned to work off to the left or right side but would be a bitch to operate handheld because the weight would be way off to one side or the other.

The side view has altered since I began fitting up the FX1 type cameras and I dont have a current accurate view.

The image tube has become shorter in order for the FX1 to "see" more of the groundglass without the prism edges getting in the way. It still works for VX2000/PD150 in this shorter version, in fact better than the original.

From lens hood mount rear face to the AGUS35 Nikon Mount front face is 111mm. The whole thing, including motor, glass disk and 1.5v battery, without lens attached weighs 874grams.

The optical centres as originally illustrated are pretty much as built for the PD150, HDRFX1 and for the the DVX100 they are fine when matched up hand held. The current .pdf files in media/hart are no longer correct for the design and should be ignored.

I have a profile for the DVX100 lens hood bayonet mount but I don't have the correct orientation so will have to inspect a camera again or get somebody at dvinfo to scan or photocopy the hood from the camcorder side to see the correct orientation of the bayonet lugs relative to the set screw. - Any volunteers??

Bob Hart
January 19th, 2006, 01:33 AM
I have tried uploading 5 very short uncompressed .avi clips to the following address.

http://www.putfile.com/bh_107f

They apparently cannot be downloaded and must be viewed off the site . I've tried working them and they don't seem to work but it might just be my mismanagement.

Maybe somebody can give me some advice. All I am doing is becoming frustrated and getting the red mist, which is not good for stress mitigation.

The clips are one from night-vision into PD150 and the rest, tests into HDRFX1. The titles are bh-AR001 to bh_AR005.

Whilst the performance of my version into the HDRFX1 cold be described as adequate, there are other versions which do better.

Regards all.

Bob Hart
January 23rd, 2006, 07:02 AM
The clips I sent up which are mentioned in the previous post do not work. It seems I have mismanged them so I shall try again sometime soon.

Today, I took an FX1 attached to an AGUS, down to one of our local TV broadcasters who kindly allowed me to use their Lemac chart.

I put all the Nikon mount prime lenses up at two aperture settings, wide open and f.5.6. Also I tested the 12mm -24mm Nikon digital zoom wide open only and found with careful attention to backfocus and actual focus, this lens can perform as the equal of the others. The f2.8 135mm Auto-Tamron also held up as sharply. This is an old lens of the Adapt-a-matic series not Adaptall.

Tje 12mm - 24mm digital zoom surprised me as my impression was it was a distinctly inferior lens in this application. Against my expectations the 50mm lens at f1.8 suffered the most for being wide open. So much for one's assumptions based on casual observation.

After running the test, I then found, that the vertical and horizontal bar blocks are marked as not resolveable by video which left only the Siemens star focus indicators, the four "eyes" in the corners. These suggest there is little difference between the best resolution off the disk and the camera's own view. However, their appearance fluctuated in a regular periodic beat which altered when the disk motor was shut down.

The hoizontal and vertical bar blocks seem as visible to the camera through the disk image as they are directly. The "B" and "G" blocks yield a moire pattern which suggests they are being resolved. This leaves only the finest "A" and "F" blocks as not being resolvable both via the disk image and direct to camera.

The fluctuation on the Siemens indicators suggests the disk is still running out sufficiently to affect backfocus at HD resolutions. The disk seems to run true by eye match so the issue may instead be end float which in my device is contolled only by the magnetic field of the motor.

There remains an added slightly warm greyish cast to the colour compared to the camera view under the same lighting. It can be white-balanced out.

Constrast seems to be reduced.

The two grey scale blocks at the darker left side of the bar were less separable than in the direct camera view.

View was via the FX1 LCD flipout screen. I have no HD capture facility. The broadcaster did not either as they use their HVRZIUs (similar to HDRFX1) for news in the DVCAM mode.

Lighting was by one 500watt flood which their camera department had just finished using for their own test.

The camera was left in full automatic mode fir all functions.

The test suggests there is room to allow slightly less resolution in favour of a more filmlike image off the groundglass and yet find an acceptable performance into a HD capable camera. This is consistent with Ben Gurvich's observations on the SD footage I have sent to him for comment.

The problem with falloff due to the proximity of one edge of the combined prism path remains for the FX1 which uses more of the area off the groundglass than my own camera, the PD150. I hope to resolve this by using longer but also thinner prisms which should fit into the same workspace as the 40 x 40 x 56mm x 40mm common thickness set I now use.

Images as .jpg files are going to be of limited use as I can only create them via the MiniDV codec. If anyone wants to see these I can post them at putfile if they are requested here.

The news cameraman I spoke to was interested in terms of being able to put long lenses on the HVRZIU.

The above information is relevent only for versions which use the 24mm x 18mm image frame off the groundglass. The FX1 is actually taking a little more width than that and slightly less height at full zoom-in via a +7 acromatic dioptre.

Bob Hart
January 24th, 2006, 11:11 AM
If anone is still building spinners, there is a part which may interest you in terms of setting backfocus and focal plane alignment.

There is a generation of very low cost DVD players which are being found on roadside rubbish collections (in Australia at least) or discards from repair shops as being uneconomic to repair.

Some of the slimline styles with centre trays use a transport, the SHINWA SHD-2502. These have analogue motors for spindle, tracker and loader. The spindle motors have a short shaft, which enables a more compact device. The motors are smaller in profile than older CD player motors but have the same face mount system and centres. The build precision of the shaft to bearing fit is quite amazing.

A bonus is that they have a three axis adjustment on the spindle motor mount similar to the arrangement for analogue tape recorder heads, ie., one fixed screw on a pillar and two adjustment screws which bear against two small but strong compression screws beneath the motor mount plate and secure this to a subchassis.

By cutting away a small portion of the subchassis to carry the motor mount assembly, a precision three axis backfocus and focal adjustment, an adjustable motor mount, ready-made becomes available and requires only simple fitting to a less sophisticated structure. - Epoxy glue even.

The downside will be that being mounted against spring pressure, there is potential for movement if the device is knocked or bumped. However if the DVD players are capable of surviving longdistance transport, I doubt careful use of an AGUS device will make any more demands than this motor mount arrangement can deal with.

These analogue motors may not continue to be available as there seems to be a newer generation of DVD players with brushless DC motors which require a digitally controlled pulse power supply like CR / DVD recorders, burners and scale aircraft electric motors. There remains one analogue motor for the load tray. Removing the spindle from some brushless motors of the outrunner style has proven impossible.

The shaft diameter of the brushless and analogue motors appears to be the same.

I find the availability of spindle hubs a greater difficulty as you only get one for every three motors you salvage.

Good luck folks.

Bob Hart
February 6th, 2006, 01:01 PM
I have again attempted to post short clips in H264 Quciktime this time at this address :-

http://www.putfile.com/bh_107f

The stupid part is I cannot download them back to my email computer as it is a dog. So I can't view them off the web. If ayone actually gets them to work, I would appreciate the advice that they were viewable.

Here follows some furthur useless information for ayone who may be trying to build a plumbers version.

It is a grab from a recent email I sent.

""""""""""""""""""""""""""""""""""""""""""""""""""""""
Hello again.

My diagrams don't show one or two later developments.

Since I fitted up a HDRFX1, I have shortened the length of the image tube to compensate for the thickness of a proper Nikon mount on the front cap and for the FX1 to be able to focus on a wider piece of the groundglass. This involved cutting about 10mm off the front which leaves about 8mm from front of case to front of tube and about 14mm off the back to enable closer coupling of the FX1. The pipe caps themselves now have to be trimmed down as well so they don't fetch up short against the case.

This also involved moving the motor mount closer to the camera by adjusting it with the adjusting bolts to within about 14mm of the front face of the rear prism which was another reason to shorten the image tube at the front. To keep spring pressure I had to put some spacers under them between the front case and the motor mount.

You also need to have a restraining device to stop the disk from moving up and striking the front prism which overhangs it. This can happen if the device gets bumped hard or dropped.

At the Cunderdin Airshow last March, the device dropped off the front of the camera and hit the ground hard while running and shattered the disk and chipped the front prism. I had quickly assembled it with glue tacking, meaning to make permanent screw fitting later and forgot once I had the thing working the way I wanted it. The glue softened in the hot sun because I had the device painted flat black.

There should be a little hook bolt (a cut-down and re-threaded bicycle spoke) from a hole in the motor mount plate below the battery holder and a little to left of the bottom motor mount adjustment stud, - through a hole in the bottom of the case and a small nut or spoke nut to pull up the slack and restrain the motor mount and the disk downwards to keep prism to disk clearance at about 1.5mm.

In the end I got lazy and just glued the adjustment nuts and exposed areas of the studs at the motor mount with lots of silicone bathroom sealer and put a little piece of cardboard across the bottom face of the prism after I set backfocus.

Feeding the bicycle spoke through whilst trying to fit up the motor mount is a real pain.The nut and the spoke end sticking out the bottom is untidy. It also adds complication to the backfocus adjustment and could put it off if the spoke was knocked during use.

Backfocus is easy but has to be very precisely done, otherwise the wide lenses like 24mm, 28mm or zooms will not focus sharply.

All three motor mount nuts are used and interact for backfocus and alignment. The bottom one allows vertical alignment with the lens centre-axes as well as backfocus. . Each side one allows horizontal alignment with the lens centre axes as well as backfocus.

Because the side adjusters are below the image area on the upper half of the disk, screwing the bottom adjustment in (frontwards) actually causes the upper half of the disk to move backwards.This adjustment equally affects the adjustment of both of the other two side adjusters simultaneously.

I set initial backfocus by using the depth gauge of a vernier caliper and measuring from the Nikon mount front face to the front of the glass disk. Because I grind the rear face of the glass closest to the camcorder, the measurement is 46.5mm less the disk thickness which is 0.9mm for my glass home-made disk. So it is about 45.5mm.

I find it helpful when setting each adjuster, to gently press against spring pressure, the motor mount near the nut being adjusted to pop the mount slightly off focus at that point and allowing it slowly to come back onto focus, then snugging the nut up against the plate then letting go. You have to apply pressure very near to the nut as the mount plate can flex if you are not over the spring and the adjustment is then no good.

You need to have a distant defined object like a radio tower on a hilltop and a good tripod for a successful backfocus adjustment, though I have also fluked it by measuring to an object on a wall from the groundglass, then setting the lens to that distance by the number on the lens ring by the same method of focussing the edges of the image.

You check the Nikon lens groundglass image at each edge left and right, top and bottom by using pan and tilt on the tripod to place the same distant object at each of the edges in turn and adjusting the nuts for sharpest image at that point. When you have the edges all the same sharpness, the centre should be correct. When setting this up you need to have the Nikon lens on infinity focus.

If you are in a hurry, then just sharpen the two sides and the bottom edge of the image as you see it in the camera LCD. this should be close eough but not always as good as it can be.

With the FX1, and Century Optics 7+ achromatic dioptre, the groundglass image seems best when it focusses sharp to the camcorder when the camcorder's distance scale reads 1.4 metres in the LCD viewfinder.

The polypropolene sheet (sometimes used as whuiteboard material) is less acoustically live than harder plastics and less likely to transfer motor noise conductively to the camcorder body. It is softer and may change shape over time which means periodic checking of the backfocus may remain necessary.

I try to reduce this tendency by fitting a flat washer on both faces of the motor mount, ie., the spring side and the adjusting nut side. So far, the backfocus has held true during transport and use. It is more likely to go off during a long period of storage. I recommend storage of the device in the upright position so the weight of the motor and disk bears directly along the plate and not frontwards or rearwards through it.

When I update the design I will email the revised pages.


Regards

Bob Hart

"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""

What I forgot to add was that the relay focus has to also be evenly sharp across the image frame. I achieve this alignment by making the three screw holes in the sides of the caps into slots, not round holes, adjusting the cap for best sharpness across the gg after Nikon backfocus has been completed, then snugging down the screws firmly so the rear adaptor which fits up to the lens hood bayonet fitting remains square-on relative to the groundglass.

Bob Hart
March 6th, 2006, 08:19 AM
An update on the image tube/prism block.

The design has been altered to move the horizontal (front) prism apex 3mm to the left as viewed from the rear. The apex of the vertical prism remains the same. The effect of this is to move the falloff area attributable to the horizontal prism apex and vertical prism edge out of the left camera frame as viewed to permit a larger 16:9 area off the groundglass.

This has a side-effect of shifting the frame centre relative to the radius of the disk and may require the image tube centre to be moved about 5mm outwards relative to the disk enclosure.

This is to allow the prism block to be turned anti-clockwise as viewed from the rear, about 7 degrees in the image tube to restore the correct tangential relationship between the lower side of the horizontal (front) prism relative to the groundglass disk.

The two original 40mm x 40mm x 56mm x 40mm common thickness prisms are replaced with two 45mm x 45mm x 65mm x 32mm common thickness prisms, which more closely resemble porro prisms.

To compensate for the added thickness, apex to apex of the two larger prisms, the two prisms are to be installed face to face and fixed to each other by UV curable optical grade adhesive. This will also eliminate a narrow space between the two prisms which is a dust trap and impossible to clean except by dismantling the prism block.

The glass disk I am currently using has a 5 micron finish with a slight backpolish, made using the same method as the original disk which was broken. This disk had been originally rejected as there were defects in the groundglass finish. The defects were larger pits remaining in the finish resulting from the original cutoff process which had not been dressed out by the first coarse grit run. I could be dreaming but the existence of this coarser defect in the finer grade finish seems to produce a slightly better image than my original disk.

Finally, totaly off-topic. The cat (the ginger one in some of the test images) decided my carefully marked out mount mount plates waiting to be cut out from a polypropolene sheet was a ideal place to deposit the biggest furball in the whole entire universe. I didn't see it for two days by which time the biro mark out lines on the polypropolene had become bleached off.

Alexandre Lucena
March 6th, 2006, 12:45 PM
Go ahead and write a novel on this subject.

Wayne Kinney
March 6th, 2006, 01:04 PM
I have been watching your progress in this, thank for sharing!

Bob Hart
March 14th, 2006, 08:37 AM
For those who might be making erecting (flip) versions out of PVC pipe and caps and finding great difficulty in getting the centre axes right. -------------

If you are measuring from the front face of the front cap and the rear face of the rear cap to get them parallel to get the centre axis of the SLR lens, the centre axes of the prism path and the centre axis of the video camera lens all parallel and finding that despite your very precise and meticulous efforts it doesn't hang together right and you get a big soft edge to your images, very likely it is not your fault.

PVC pipe caps like many such injection moulded products have a shape memory. The plastic wants to go back to that it once was, a blob. There are latent stresses within the material and when you cut a hole through it, the cap will deform slightly, most times the centre becomes bowed inwards.

With a non-erecting version, the lens mount will most likely be placed dead centre in the front cap, the camera dead centre in the rear cap and any concave deformation in the cap will not cause a problem as the deformation is centred on the hole.

An erecting version is another matter. The lens mount is likely to be fitted over a hole cut well off centre in the pipe cap. In this instance the centre of the lens mount and the centre of the concave deformation in the cap do not coincide. The lens mount will not be correctly aligned even if the front outer rim of the pipe cap is.

The solution to making sure the lens mount is parallel to the rear cap, is to place a straight edge across the mount face itself and measure back to the rear cap from that. An alternative is to place the device face-down onto a plane surface such as a sheet of glass and with the lens mount face firm on the glass, measure back from the surface of the glass to the rear face of the rear cap.

The caps themselves will be unlikely to be parallel to each other once the face of the lens mount is made parallel to the rear cap.

The rear cap will also present the same problem but the hole for the front-end of the camcorder is much larger and the effect of the deformation less evident. This also only has an effect where the device is directly mounted to the camera via the filter mount of the lens hood bayonet fitting.

Okay! The next question is how do you adjust for the deformation. Fortunately, the deformation across the front face of the caps the caps after the hole is cut is much less than the angle of taper inside the caps where the fit is over the tube. It is a simple matter of skewing the cap slightly on the tube until the parallel adjustment of the front face of the lens mount to the rear cap is achieved. Once the alignment is right, the screwholes are drilled and the screws fitted.

This method is also only known to be valid for Nikon mounts. There may be difficulty with Canon mounts because of the collar on front of those mounts.

Like the rest of the appliance the method is not every elegant but it does work.

A better method of course would be to machine the front face of the cap but then the construction method would have to move from the kitchen table to the machine shop, which rather defeats the purpose of this exercise.

Dennis Wood
March 14th, 2006, 10:57 AM
Bob, someone should be giving you an award. Your posts both historical and current are a huge asset/help to the adapter world. Cheers!

Jim Lafferty
March 16th, 2006, 01:29 AM
Hmmm (http://ideaspora.net/maserati.wmv).... history (http://ideaspora.net/spotAdapter35mm.wmv)...

Agus Casse
March 16th, 2006, 09:34 AM
i just love the cigarrette video... i remember that it was like 5am when i recorded it...

Jim Lafferty
March 16th, 2006, 11:35 AM
I think I can safely say many of us here have a fond memory of that video, too :) That's why I've kept them all... maybe soon I'll do a "history of the 35mm adapter" video for the wiki entry and just for kicks on my site.

Let me know who I'm forgetting, because this is the timeline as I remember it:

1) Agus Casse introduces the idea; made from about $20 and assorted parts from around the house, glued together. Over time, many people contribute to refining this design concept over a myriad of implementations...

2) Alain Aldus moves to the first static design, using aluminum oxide ground glass -- the Aldu35.

3) Brett Erskine schools everyone on the value of condensors, achromats, etc.

4) What is to eventually become the RedrockMicro implementation of the "spinner" styled adapter makes its debut, bringing on the first of the commercial endeavors of many to come...

5) Frank Ladner is the first to successfully employ microcrystalline wax and shows what is in my opinion the best static DIY adapter footage evar.

6) Quyen Le develops, along with Brett Erskine and others at the same time, the first practical oscillating GG device.

7) ...

Quyen Le
March 16th, 2006, 12:05 PM
Agus Casse

Happy to see you around. Do you have anything in your sleeve to influence people here? Thanks for sharing your technics and designs.

Jim Lafferty

Don't forget Dan's works, he has contributed a lot. From number 7 and on, it's hard to come up with anything new unless we have some breakthru technics. All the flipping, relay ... have been on the market and are not new. Hope some of us can someday comes up with something significant, thanks.

Quyen

Bob Hart
March 16th, 2006, 12:18 PM
Agus.

Long time no see.

I seem to recall you were working at a TV station. How is that going? Have you progressed your own device or still using what works best for you?


Quyen.

I think I might have a handle on the ghost image thing some operators are experiencing.

I was doing some outdoors tests with wide lenses trying to wring the last bit of sharpness from them. I happened to pick up the sun through tree leaves and there was its ghost image, shimmering slightly in harmony with a slight runout I am getting with my current disk.

I think it is occurring, on my specimen at least, between the shiny side of the groundglass which faces the front and the optics in the SLR lens.

This might be a case for reversing a popular preference for placing the groundglass surface closer to the camcorder.

Agus Casse
March 16th, 2006, 02:40 PM
Thanks Bob, you are my hero to keep this thread alive... actually the proyect is not really dead, the problem is that i cant find the right components to make a new and improved version. Works have been a bitch, but i think i can find the time to get back to the proyect in a couple of months.

Jim Lafferty, actually there is a old thread, which a guy put a razor and make the adaptor vibrating.., and actually my first version was using vibrations. also remember that my adaptor uses diopers, and achromats.


Quyen Le, i have been reading a lot of post about new adaptors, and i have received a lot of emails if i will make a commercial version, thats is why i am talking with a industrial designer, to find a way to make this thing cheap and with milimetric presicion.



see you guys soon...

Jim Lafferty
March 16th, 2006, 04:01 PM
Ah... I thought you'd just used the credit card magnifier or the glass from a reading magnifier and not an actual achromat. I guess in trying to condense the history, I'm looking at the peaks and not all the smaller developments on the way. I'm pretty sure it was Brett who came to the table with much of the achromat research we all benefited by, and that's why I put his name there.

Bob Hart
March 21st, 2006, 12:11 PM
Resolution Tests with an AGUS35 style device on a Sony HDRFX1 PAL.

The image yield occurred with the following path.

Test Chart >> SLR lenses at f1.8 >> AO5 groundglass (backpolished slightly) >> two prisms >> Century Optics 7+ achromatic dioptre >> HDRFX1 camcorder.

Conditions were adequate artificial lighting of the test card. Camera fixed on a sturdy tripod. The frame taken from the groundglass is 16:9 and about 26mm wide.

Today, I looked up the resolution scale printed on the back of a Lemac test card. I shot some lens tests with this card about two months ago. I had misinterpreted what these resolution indicators mean and wrongly assumed they all were invalid for assessing video.

The resolution of the FX1 LCD flipout screen may not be that of the camera system itself. In the screen, all but the "A" and "F" indicator patterns were visible. Whether the camera is actually seeing the individual lines in the finest visible "B" and "G" patterns or there is a moire interaction happening I don't know. But it seems from the LCD screen that the pattern is being detected.

For a moire interaction to occur it would seem that the CCDs of the camera should actually be seeing the fine patterns of individual lines. However it might not be necessary for the lines on the card to be seen at correct resolution for a moire pattern to be generated. It might happily occur if every second or third line was seen by the camera CCD for moire to occur. I simply don't know enough about the subject to make assured comment. I have not yet been able to get access to a high definition monitor to look closer at the recorded image.

That aside, if the camera CCDs are seeing every line in the "B" and "G" resolution indicator patterns, then according to the card, horizontal resolution is up to 864 lines and vertical resolution is up to 486 lines.

This hints at a better result than my guess of 700 lines from the EIA1956 test pattern from earlier tests into a PD150. The PD150 is apparently limited to 530 lines and that is where the separation of the four tapered lines ended. But there remained hints of the tapered line pattern outward into the 700 zone to about 710.

According to the card, the higher resolution "A" and "F" indicator patterns will not resolve on HDTV anyway. These are 1920 lines and 1080 lines respectively.

If my fairly rough and ready appliance with its home-made groundglass is truthfully yielding these results, then better results can be anticipated from the more thoroughly designed appliances with better groundglasses.

Bob Hart
March 22nd, 2006, 01:45 AM
A hint for anyone building an AGUS out of plumbers pipe and pipe caps.

The f1.8 lenses give you a nice wide area of light across the groundglass, larger than the 25mm or so the 56mm hypotenuse prisms will allow. When setting up the centres on the camcorder mount and the front lens mount to make the holes in the pipe caps, a little laziness may creep in and an adjustment to the front cap (ie., a remake of a new cap = lots of work and a wasted cap) one tends to leave the front cap as-is if the most vignette prone lens in the arsenal works okay.

You set up the backfocus across the entire image, by aligning the lens mount true to the rear camera mount, correct the backfocus again then fine tune it with the three adjustment screws while sighting on a infinity target, fuss around until all the interactive effects have cancelled out and are then well pleased with this beatific smile on your face.

Then you go and do a real-world test and find there's a soft edge or a corner. It's consistent across the entire range of lenses but more aggravated with the sides and turns up when the lens is focussed on something midway in the range. You check the device. All the glue locks are intact and nothing has moved. You didn't leave it in the sun to cook and nothing has bent or gone soft.

Then the dim realisation begins to pall. You stop the lens right down to get the darkest vignette and there it is. The lens is off-centre relative to the camera view, something the wide lenses will not accommodate, especially on closer objects.

On reflection, I would have saved myself a lot of time and effort and sacrificed pipe caps if I had made a facility for lateral adjustment of the lens mount position along the radius of the pipe cap, a simple slide and clamp arrangement and used the rotation of the cap itself on the image tube to provide the second direction of adjustment.

There is no room for unthoroughness and expediency in this business.


Another caution. If using small self-tapping screws to fasten into the PVC, take care not to screw them in fully home in one hasty journey to firmness. They generate enough heat to melt the plastic but also to cause a heat related stress rise where the head of the screw joins to the shank.

The plastic cools and sets on the screw threads. Later, you decide to dismantle, there is a gentle SNAP!! and the head comes off the screw. It has happened twice.

Grooved self-threading screws such as found in some players and videos, might be a better choice.

TEKs are no good as the drillbit on the end is too wide for plastic and will cut too much away for a secure fit.

Don't use the knurled screws which look like the threads are a sort of rasp or file to cut threads into the plastic. These will begin to strip the hole if fitted more than once as they are not intended to be unfastened.


Quyen.

If you are reading, I had a random thought about high definition resolution on your device. It might be worthwhile getting a few microscope slides from your nearest university medical faculty, high school or from a pathology service, a piece of aluminium cooking foil and some of Oscar Spiers wax formula.

I tried it wax between two disks but abandoned the idea because I was not able to control the thickness of the wax layer consistently around the whole disk. The image quality was by far the very best but the flicker was totally unacceptable = 1.5 f-stops.

Because your groundglass has a much much smaller movement than a spinning disk, consistency of the thickness across the groundglass should not be the same problem.

The problem would be locking the two glass panels together so that the wax and glass do not separate due to the vibration. The vibration and travel of the groundglass may be adversely effected by the extra weight and the wax composite panel of course will be vulnerable to effects of heat like any other wax gg. The lesser grain of the wax however may enable a smaller travel of the gg and make for a quieter device. - Just a thought.

Jamie Roberts
March 24th, 2006, 05:58 PM
Hi all

my project to make an agus35 is officially finished. Its as the original one is, I gave a 10x macro lens between the camera and the gg, I have mounted a 40mm plano convex lens between the gg and the 35mm lens (closer to the gg), gg is sanded plastic CD mounted on a cd walkman motor, and i am happily able to shoot in widescreen on my gs400 without any hotspots, lightloss around edges etc. The money thats gone into it is about $60 australian and the results in my opinion look great in terms of acheiving shallow dof.

these threads have been invaluable in helping a clumsy novice like me make such an effective bit of kit! thanks alot

jamie

Carl Jakobsson
March 24th, 2006, 07:16 PM
Jamie, I would like to see some footage. I also believe in sanded cds... :)

Dennis Wood
March 24th, 2006, 08:09 PM
Jamie, I'd love to see some PAL footage from your GS400 with the adapter. This is from my GS400 with my spinner (now sold):

http://www.filefactory.com/get/v3/f2.php?f=a420ed2a064268f3d5e956b9

The GG is 1.5mm optical acrylic, fine media blasted on a rotating jig (at 1000rpm).

Bob Hart
March 24th, 2006, 10:52 PM
Night Tests. AGUS35 to HDRFX1

For sake of some real-world testing, I went down to the local retail dragstrip and on into the city and shot some unassisted footage in the night. I stopped by the caryards in Vic Park on the way home. They are well lit and a cheap way of seeing how the system performs under good lighting. As usual, the roving security people give you a strange look and passing fitness walkers do likewise when they see the weird gadget on front.

The light loss of the system is most apparent on the cityscape.

The direct-to-camera images are bright enough for the overhead scud cloud to be just visible.

The light loss through the system is very noticeable, especially through one lens, the 12-24mm zoom which is f4. However, and this is weird, there was not the apparent two-stop increase in the brightness from the f1.8 lenses I expected to see. I can't work that one out at all.

From the relayed images, all you get is the pinpoints and dim window rows on the towers. Direct-to-camera picks up spill from streetlighting onto the sides of buildings. So for night footage of cityscapes, the relay system might better be abandoned in favour of direct-to-camera.

Another weird aspect is that I forgot to turn the disk on for the first two lenses and there is no groundglass texture to be seen.

The longer lenses perform better, mainly because any bright light sources such as signage occupy a larger portion of the image and are recognisable.

Under the bright lighting of the caryards all the lenses performed well. Except for the increase in brightness and better contrast, there was little discernable increase in apparent image sharpness between the relayed and direct-to-camera images.

Again, there was very little discernable difference between the f4 lens and the f1.8 lenses in this lighting environment. On a high definition display it likely will be a different story but I have no acccess to one.

I also shot one test with a single lens in a streetscape after light rain. The area was moderately lit. With the gain fixed to keep the blacks less noisy a pleasing and realistic image can be had.

I have tried to put motion files up on www.putfile.com but have not been able to download them to view them so have no idea if they are downloadable or not. Can somebody give me some advice on the best compression system for placing motion files there?


Jamie.

Congratulations on completing your project. Now may likely begin, the obsession of trying to make it that little bit better.

If you have a chance sometime, could you post a frame grab somehere. I'd be interested in seeing how the condenser performs in your arrangement.

For field of view without a condenser, my arrangement frames the 16:9 Lemac chart in a 25mm wide frame on the groundglass with a Nikon f1.8 SLR lens set at 1.0 metres from chart to groundglass.

Dennis Wood
March 24th, 2006, 11:34 PM
Bob, try http://www.savefile.com/ for uploading files.

For sample footage at full frame size, windows media 9 (MPEG4) is hard to beat. Encoding takes a long time, but at 3000Kbps, the quality is better than max bitrate MPEG2, IMO.

http://www.freefunfiles.com/software/audiovideo/encoders/windows-media-encoder-9.html

For NTSC HQ anamorphic footage 16:9, I resize to 872x480 square pixels, and encode at 3000Kbps. That's about 17MB/minute. All of my uploads for adapter footage tests are done that way.

For NTSC lower quality anamorphic footage 16:9, I resize to 436x480 square pixels, and encode at 500Kbps.

Hope that helps. If you want a few .wme files email me. They can be loaded into the encoder and will have all the settings done for you. You just will need to change source and destination file locations.

Hope that helps. If you're on a Mac, H264 is the MPEG4 to use...and I can't help you :-)

Jamie Roberts
March 25th, 2006, 12:25 AM
i am going to do a little staged shoot tonite here at home using artificial lighting.

will put something up as soon as i have something.

cheers

jamie

Bob Hart
March 25th, 2006, 06:50 AM
First look on a high-definition plasma screen.

Today I took a FX1camera and a component patch lead across to our neighbouring Harvey-Norman and they graciously permitted me to playback tests in the high-definition realm.

I have to confess that despite my scepticism, the playback looked a lot better than I had expected.

The pitfalls of the home-made relay device soon became apparent.


Sharpness of the image.

The AO5 finished groundglass texture can deliver an image of adequate sharpness. Maintaining the sharpness of the image delivered to the groundglass is another matter.

Focus failed on two levels, the relay and prime lenses, both due to operator skill or lack of it. In a production environment, a high-definition monitor would be essential. Being short-sighted, I occasionally overlook soft-focus given that it is my natural normal vision state.

I also found that making lens changes often meant the camera focus ring was bumped. This needs to immobilised after relay focus is set as another participant at this site has already observed.

Light levels onto the groundglass also seem to have an effect. The camera's ND filters amd manual apertures have to be used more and with more precision. Some interactions occur between the prime lens aperture adjustments and the camera aperture adjustments which can add to or subtract from sharpness.

An image containing a strong large area backlight and a large area underlit foreground was almost impossible to resolve without visual artifacts from the groundglass disk appearing.

This was most apparent with a f4 12mm-24mm zoom which only leaves one f-stop of adjustment before the f5.6 rule is broken. If lens aperture was adjusted to reduce the overexposed area, artifacts appeared in this area. If the camera aperture was opened up, the artifacts moved to the underexposed area. The f1.8 lenses fared better but it is a fine tapdance trying to find the best combination of both aperture selections and the ND filter.

The scene was views along a roadway lined with thick forest under light 7/8ths overcast with patches of clear sky. A graduated ND filter might be the only way to resolve this image if it possible at all. It is certainly a scene I would avoid.

"Magic-hour" shots looked great, especially with light from behind camera, in the direct light or in open shade. The sharpest images were achieved in this circumstance. A one-stop manual under-exposure seemed to yield the best sharpness and colour rendition.

The colours of backlit foliage in the "bokeh" areas was an excellent effect, likewise at night, the various colours of lights when focus was moved from very close to on-subject with the 85mm and 105mm lenses.

Another effect on sharpness was observed and has been previously commented on. There were occasional slight momentary focus shifts due to end float on the disk motor allowing the groundglass to move off focus. There is only about 0.25mm in it but it is enough in the HD realm to spoil the image. Up until today, I thought I had eliminated the problem.

A possible solution might be to fix a large metal washer very close to the motor side of the groundglass with a large enough centre to surround the hub and using the magnetic piece found in some CD players which clamps the disk. The magnetic field may be enough to keep the motor armature back against its rearmost limit without adding the friction a home-made thrust bearing would.

The night footage seemed softer and flare in the relay images was more apparent as one would expect from the many extra pieces of glass in the path. Except for inferior contrast, there seemed to be less difference between the direct-to-camera images and the relayed images than during natural daylight.

There was one incident of chroma separation on the right side of the image as viewed. I attribute this to the prism path as it is not uniformly spread around the entire outer edge of the image. It showed where a bright tripod leg intruded into a darker area of the image which was also slightly out of focus.

The earlier tests which made apparent the misalignment of the groundglass and lens centres were woeful to see in the HD realm on a large screen.

I found I had some eye tiredness after 50 minutes of viewing. I experienced this eye tiredness to a lesser extent after watching "Star Wars Episode 2" and on a par with that I experienced after watching "Open Water" , both movies in a theatre.

Overall, I think one could make a low budget feature with this combination but it would require a stressful degree of close vigilence and avoidance of some lighting situations, notably, large untextured areas of overlit background and underlit foreground of more than two or three f-stops of difference.

There's a way to go yet with this project.

For now, the FX1 goes back to its own home with my fingerprints on it and it's back to the PD150 for a while.



Dennis.

Thanks for your hints. I'll give that a shot.

Jamie Roberts
March 26th, 2006, 03:38 AM
Hi all

heres a link to a short clip that i did up today that shows my agus35 adapter in action!

http://www.filefactory.com/get/f.php?f=ae5233b7043a59388db778dd

Inside stuff really didnt have enough light but i kind of liked the way it looks anyway. Outside clip at end is to show how it looks in good light.

Im not after perfection. I will definately use it for close up shots where i think it really comes in handy. I would like to now continue on im my efforts to actually make a decent little movie!

I can see how easy it would be for it to become a hobby in itself just working on improving a 35mm adapter but thats not me, unless some new simple idea comes along that a child could make (so I can!), i'll be content with this for now.

Jamie

Bob Hart
March 26th, 2006, 05:19 AM
Jamie.

You've done well it seems, going by the clip playback.

There's no more needed to be done for your purposes, beyond perhaps some fine adjustments, unless you want the convenience of a flipped image.

I observed no variable density flicker in any of the images so it seems you have the disk well sorted.

No evident endfloat of the spindle or misalignment of the disk on its hub is evident.

Interiors are as bright as I would expect them to be.

Corner to corner, the light intensity seems to be even, I guess the benefits of a condenser in the path at play here.

In the exteriors there is a hint that your disk might not be square-on to the focal plane or the camcorder centre axis might be slightly off, but it is usually the disk alignment itself which is usually more affecting to the image.

As I see it, the left edge of your disk may be about 1.5 mm rearwards and the top edge of the disk about 0.75mm rearwards, relative to the centre. This is really only wild guess as I am going by the soft areas in the backdrop of the hedge and the nearby roof eaves which seem off in the right and upper portions of the image as viewed.

This is however very much an assumption. It may be that the hedge is not square-on behind and the roof eaves in a genuinely out of focus area so don't take too much notice of this comment.

The interiors seem square-on as far as the disk alignment goes so you might be getting a bit of flex with the CD-R case if that is still what you are using.

A little circular piece of plywood fastened to the inside front of the CD-R case with screws and silicone sealastic to stiffen the front structure might be the way to go if flex is happening.

This is the beauty of Agus's original design, a result tantalisingly close to the P+S Technik benchmark for a miniscule fraction of the cost and well within reach of the budget and construction skills level of the enthusiast.

The one and only motion video file at www.dvinfo.net/media/hart was shot on a non-flip version ith a plastic disk. Feedback suggests preference for the image from this plastic disk compared to the image from the glass disks.

Jamie Roberts
March 26th, 2006, 04:43 PM
thanks for that Bob.

You are probaly on the money in terms of the disc being slightly out. I also actually used an ultra thin sanded plastic disc that i found in a spindle of dvd's. maybe its too thin and wobbles a little. it would be half the thickness of the std clear plastic cd's u get.I was hoping the thinner one would allow more light.

thanks also for the good idea about reinforcing the front of the housing.

Jamie

Bob Hart
March 26th, 2006, 10:07 PM
Jamie.

Your disk is running true so I would not mess with it. The DVD clear spacers are good. They are optically true and run true if they are the ones you can see a slight trace of the guide tracks on (looks a bit like opal against the light). This is the surface you sand or grind away at.

You may well have hit upon a good combination. The DVD spacers or split DVD disks seem to be made of a harder composition than the older CD-R spacers. The DVDs don't seem to dress as easily using the abrasives I use for the glass ones but when you get a successful one, they seem to be as good as the glass. They also run true because they are thin and can bend and the centrifugal force takes care of any runout in the hub.

The more aggressive sandpaper with fixed grit might be a good solution for homebuilders. Once the abrasion has started, then a dressing in a fluid abrasive might be viable for a finer finish.

I made one and the image was more filmlike than the glass but it got a circular scratch on it from a screw-end sticking through the motor mount. When I took it off the hub to dress it again, I furthur damaged it and I have not been able to successfully make one since to replace it and am back to glass which I know.


With your arrangement, if there is mis-alignment, it will be in the fixed position of the disk/motor/motor mount assembly. I am assuming in all this that your condenser and SLR lens are both correctly centred relative to each other.

How have you mounted your disk motor? Have you provided for any adjustment? If you have screwed it straight onto the rear cover of the CD-R case from the outside and have mounted the hub and disk on afterwards on the inside, there may be some flex going on there in the case. If that is what you have done, then a round piece of thin plywood, screwed onto the case surrounding the motor and three screws with the ends filed off flat so they don't puncture the plastic case, threaded through the plywood at the points of an imaginary triangle, each point about 25mm out from the centre, pushing against the plastic to bend it slightly when you screw them in, might distort the plastic of the case enough to give you that final trim adjustment. It would be a cheap and nasty fix which would drift over time as the plastic slumps.

A better method is to mount the motor on a plate and fix this plate to the case. I use three small gutter bolts fixed to the case with nuts, then a small stiff coil spring around each bolt, the motor mount plate sitting on those, then another nut and washer on top to screw down to press the mount plate forward or loosen off to release backward using the spring pressure. In your arrangement, you might need to fasten the bolts to the motor mount and have the adjusting nuts on the outside of the case where you can get at them, as you don't have the same workroom to fit them around the disk inside the case as I have with the pipe caps so you are limited to mounting and adjusting from the rear of the case. It is a better solution for adjustment in the field as you don't have to take a cover off like I do.

If you can get hold of or photocopy a Lemac chart with the four Siemens circles in the corners, these make an excellent back-focussing and alignment aid as you can adjust until all circles are the same sharpness.

Jamie Roberts
March 27th, 2006, 12:02 AM
Im afraid my motor is glued in well and truly with liquid nails!

One thing i am not 100% sure on and will check is whether the condenser is actually centred 100% to the slr lens and also whether the condenser is sitting on a slight angle to the gg. I dont know if the angle bit would matter much?

I have mounted the condenser in another cut back cdr housing top (like whats it mounted in now. I cut it right back so there is small lip and was able to push it in and upto the gg without interfering with the spinning etc. It actually a bit hard to check as when i push it in i can no longer see the gg except through the condenser. I know if ive pushed it in to far as the disc wont spin, so i pull it back to the disc spins fine and thats basicly my method. I will re fit it and pay closer attention to the whether the condenser is centred on the slr lens and whether there it is flush but offset from the gg.

Jamie

Bob Hart
March 27th, 2006, 12:15 AM
Dennis.

I've tried to upload a 50mb Quicktime H264 file to savefile.com but the machinery here sits and licks its tail without sending anything out. It has been a longstanding problem. Large .pdf files in which I wrote construction methods and which contained still images have the same problem.

I rang my provider who advised that my system (Windows Internet Explorer on W98SE will not handle such a large upload and that I need to use a FTP client?? The provider is not allowed to recommend any system over any other. Any recommendations or hints??

In the course of doing all this, I forgot to set the HDV to DV conversion to "on" in the camera menu but the footage captured anyway so I don't really know what is going on. The system is supposed to be "NOT" HDV capable.

Whatever? It writes a better DVD-Video disk because of it so something has been learned. The whatever it is takes heaps longer time to render or convert to mpeg4. You can also have it any way you like as long as it is stretched vertically so the file I have made was letterboxed so it presents correctly.

It might be easier to make some datadisks and send these by mail or camera tapes to people who have more knowing on computer things than I.

Bob Hart
March 27th, 2006, 12:40 AM
Jamie.

What you have there is yielding about 85% which should be adequate at a hobbyist level. I wouldn't mess with what you already have working for you as it may not come together quite as well next time. There are too many variables including the thin soft plastic case and there being no fine adjustments available.

For improvement into that 90% plus arena, I would favour a complete re-make so that you still get to enjoy the benefits of the original appliance.

I used PVC pipe caps and tube because the material is more robust and a tube enabled centres to be more accurately kept but the device remained nearly as simple as Agus's first.

Ben Gurvich has a project box version which works well. He is within a half-day drive of your patch but I will leave it to you to initiate contact to see if he is prepared to make his contact details available to you and advise if he actually has the device still with him. Ben visits this site so you should be able to get a blind email to him from here.

He is however quite busy in his fulltime work in commercial TV so may not be able to assist you.

His version I think was based on a design which I think was published by Jim Lafferty. It is robust and because it has flat surfaces everywhere is a lot easier to mark out and get centres for than a circular object. It is probably a better and more predictable project for a home-build from scratch than my own.

Bob Hart
March 27th, 2006, 05:59 AM
AGUS35 APVE TO SONY HDR-FX1 TESTS.

I was unable to get anything but small motion image files uploaded but there are four which are very truncated versions of originals and do not encompass a full lens range as the original longer clip did.

One of the clips No4 also includes aerial-image footage shot through a Sigma 50-500mm f4-f6.3 zoom.

The clips are all QUICKTIME H264, whatever magic that is. I faithfully followed advice and it worked, so thanks again Dennis for your input.

They won't play on my web computer but will play on the editing computer which I keep quarantined from this one.

Some of the shots were made before I re-centered the front lens mount so you will observe a fall-off to the left side in some shots. This is caused by the edge of frame being too close to the horizontal prism apex, a situation forced by the 28mm half-hypotenuse of the prisms I presently have fitted. I hope the larger prisms will fix this as I will have space to move the apex furthur to the left.

The web address which seems to work is :-

http://savefile.com/projects/338360

If anyone actually gets one of these downloads to play back I would appreciate the knowing.

Carl Jakobsson
March 27th, 2006, 12:56 PM
Thanks a lot for the interesting reading and viewing! The movies work fine on my Mac (Quicktime and VLC), haven't tried them on my pc though. But I suspect there's something wrong with the field order, it's most visible in the airplane and boat clips.

Bob Hart
March 27th, 2006, 08:15 PM
Carl.

Thank you for your feedback.

Field orders and compression settings, while I know of them, are a dark art I have yet to teach myself some competence in.

The original footage viewed on TV, copied over to a DVD video recorder or captured to computer, does not have those defects, so my mishandling of the computer will be the culprit.

Moises Crespo
March 27th, 2006, 09:34 PM
My35 I accually scratched the macro filter right in the middle but check out the footage.. http://media.putfile.com/Sequence-1_...bit_DSL_stream
Thanks,moe52

Jamie Roberts
March 27th, 2006, 10:05 PM
As i cant leave things well alone! I am in the middle of rebuilding my adapter with a few minor adjustments.

I noticed that the condenser was sitting a bit higher then the slr lens and therefore out of line so i have pulled the condenser and re-glued it into a better position in its support frame so lines up better with slr lens.

I also noticed that the mount that the camcorder lens goes into wasnt sitting flush with the adapter ie was on an angle so therefore the camcorder wasnt facing gg directly. I have pulled that off and reglued it so its square on to the housing.

The very thin plastic disc i was using is splitting from the centre out. too thin im afraid but I found another plastic disc that already has a fine slightly 'sandblasted' look on one side. I want to preserve that side as I think it may be effective so I am sanding the smooth side with 600 sandpaper. Anyway in the next couple of days I will get a chance to put it all back together again and see what happens! Hoping that it dazzles me so I can leave the bloody thing alone!

Jamie

Bob Hart
March 27th, 2006, 10:23 PM
Jamie.

If you've got a plastic disk which does not flicker, treat it like gold, as such are quite rare. If you have a small electric soldering iron for electronic work, fire that up and burn a small hole through the plastic where the crack comes to an end, then trim the rolled up edge of melted plastic off with scraper or old style ribbed razor blade. The crack should travel no more. The scrapers and blades can be had from hardware or ceramic top electric stove retailers.

If you don't have an electric soldering iron, a piece of thick wire cooked up over a gas flame will do.

Aligning the camcorder is a good move because it puts the best area of gg image centre in the camera's image. Though perhaps not quite as critical as getting the SLR lens and condenser centred and their common centre axis exactly at right-angle to the groundglass, getting the camcorder itself lined up places you furthur into that elusive 90% quality zone.

Jamie Roberts
March 28th, 2006, 05:17 AM
Well i have it up and running but only had time for a quick test. will do some more tests on the weekend and post a link to some footage

The disc i tried with the sandblasted look on one side and me sanding it on the other wasnt that great im afraid. I currently have put a normal gg disc back in which works fine but will take your idea about the one with the little cracks and use my soldering iron to stop them going any further, and try and use it again. its is a rare one as I havent seen one this thin before. i must start hassling all my cd/dvd burning friends to keep all their clear discs. the last pack of dvd's i bought last week didnt even have one! Just paper protectors.

seeya

Jamie

Bob Hart
March 28th, 2006, 08:53 AM
Jamie.

You can get them anytime by scrounging failed DVD burns from the bin. You split these disks along the purple layer. The purple dye sticks to both halves but the purple side on the clear half is the bit you sand off. You can use the other half but that white printable label stuff is a sort of a latex and is impossible to get off without injuring the clear finish underneath.

There may be solvents which will clean the latex or purple dye off without injuring the plastic. As these disks are not intended to be broken open, be mindful that the dye may be poisonous.

Use gloves and long sleeves and if you wet sand, make sure you ditch the water in a safe place and do not risk cross-contamination of foodstuffs or utensils by using the kitchen sink or the utensils themselves. If you dry-sand, wear a good dust mask and do the job away fromwhere your nearest and dearest might be exposed to the substances.

It is hard to get the split started but once it starts they peel apart easily.

You can try to prise them apart with a sharp point, or try to start the split by dropping them on edge onto a hard surface. It seems to help to boil them first.

IF ANYONE KNOWS IF THE DYE LAYER IS INDEED DANGEROUSLY TOXIC, PLEASE FEEL FREE TO ADVISE.

Jamie Roberts
March 28th, 2006, 11:18 PM
Well i'll be buggered I didnt know that!!! thanks for that valuable bit of info Bob.

I have managed to shoot a little bit of video today outside to test the adapter and it ont eh cameras lcd screen it looked pretty good. will capture it tonight and post a link

Jamie

Carl Jakobsson
March 29th, 2006, 08:17 AM
I've only had flicker problems when the batteries or soldering was poor. When spinning with a portable cd-motor at 3V I get no flickering, even though the disc is far from perfectly sanded. On the other hand, the motor makes a lot of noise at 3V. I use external mics so that isn't really a problem.

Jamie Roberts
March 29th, 2006, 04:13 PM
Hi Carl

thats interesting.

I have found two kinds of clear discs. one being as thick as a normal CD, stays on the cd motor fine, but can start to flicker especially if batteries are down a bit (i use 2 x AA). the other disc i have found and used are very thin & flexible, need some blu tack or something similar to keep them on the motor but spin without flicker. I have also noticed that flicker appears to be more obvious in poor light situations (unless im imagining that!). In saying all this though, yesterday i shot a small piece of test footage using a normal thickness disc and there was no flicker at all.

Bob Hart
April 1st, 2006, 08:45 PM
AGUS35 APVE TO HDRFX1 - FURTHUR REAL WORLD TEST.

I got my greasy hands on the FX1 again for an afternoon. I took it and the Agus to a teenagers rock band competition at a local festival. I used it agile-portable as one could use the camera itself alone and found a few problems.

I found another camera-operator there doing an official recording of the event so extended the original intention of a few test shots into providing a bit of extra coverage, mainly close-ups and fingers working strings and frets etc..

The conditions were overcast and light under a canvas awning became a problem because of operator mismanagement. I did not use auto-exposure because of the overcast conditions which tend to aggravate burnout.

Despite some under-exposure which provoked some video noise, the camera hung onto the colours which remained rich. The video noise itself was of a finer texture than I have seen with the PD150, not unlike film grain. It is not necessarily a bad aesthetic but not one I would deliberately pursue. The correctly exposed shots held up well against some direct-to-camera footage I also shot.

The sound was not expected to be any good at all. The other camera operator had arranged for a sound recording off the mixer so it was not an issue. Surprisingly, the FX1 automatic audio performed remarkably well in conditions which occasionally drove the overload on my ears into the pain threshold.

Because the performers jump and move around a lot, following and framing with a fixed prime lens is a problem, especially if you are trying to stay out of another cameraman's field of view. A zoom would have been handy.

The loud amplified sound brought up an interesting defect with the combination of the glass disk, plastic housing and auto-focus. I use the autofocus for the relay as it seems to be just as effective as my own hand-eye skills.

However the autofocus which had been rock-steady, would drift when I was chasing focus with the manual lens and it took me quite a while to realise what was going on because it would spontaneously recover once I had hit the sharp spot with my manual focus. It initially just seemed it was taking me a long time to manually focus. It co-incided with times I was alongside the main speaker columns.

I suspect that loud sound is being conducted to the glass disk which may be vibrating just enough to set the autofocus off when the shot on the groundglass itself is soft right across the frame.

The gyro effect of the spinning glass disk showed its dark side during faster pans and tilts. There would commence a distinct vibration of about 5 Hz, which would transfer to the case/camcorder junction and shake the picture for a second or so after the pan or tilt was completed. My flexible disk-motor mount and the springs may be contributing to this.

The camera/Agus combination did not have any added bracing for sake of keeping the weight down. Added bracing to the camera baseplate would fix the problem.

I found the extra weight of the combination a problem for me after a while, especially when working with the camera held high overhead. Elbow joint and shoulder soreness set in fairly quickly and my shots with the 85mm lens handheld became unsteady and uncontrollable. This is probably more of an age and physical fitness issue.

I found myself tending to rest the back of the cam on my shoulder and using the LCD panel ENG camera style with close-up glasses. The panel was a little too close. An aftermarket eyepiece dioptre attachment for the FX1-ZI series might be a good move for some enterprising manufacturer, or an alternative eyepiece viewfinder working off the LCD circuit.

The other camera operator will be assembling a presentation using some of my footage where it is usable so it will be interesting to see how well the Agus images integrate.