Michael:

www.intenscreen.com

Looking good Ben. How much gain (if any) was your cam dialing in? Can you comment on light loss? Any hope of an EIA1956 with and without the cam? They are nice tools to evaluate any distortion too.

How can you tell my spinner is in grave danger?

is there a way to order that screen online? It doesnt have a canadian option for dealers. how much did you pay ben?

Akkk! Bombarded with questions! :)

Whew...ok...

1. Yes, the one I'm using is the Contax RTS whatever. This is where I ordered it from:
http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=4331&is=REG&addedTroughType=search

2. I tried holding the screen up to the camcorder without an achromat, and it didn't appear to vignette, so I would have high hopes for anyone who wanted to try to build a non-achromat version of the Letus. Maybe in the future I'll pick up again on that design I had going.

3. I'm not really sure which version of the Letus I have--I don't have the flip version, if that's what you mean. I had the original Letus (back when Quyen sold them on ebay), and then when I sent it in last month to get the mount replaced with the metal version, he switched out the vibration mechanism with the shorter sticks and different plate. So I suppose I have the newer Letus version, but the only thing that I've kept from the original design is the metal housing pipe, the vibration mechanism and the mount. All the optics have been switched out. Therefore I would assume this is possible to achieve with the flip version also.

4. This footage was shot with zero gain. I hate gain, I never use it--if the shot is too dark, I either bump it up a little in post or go find some lights ;).

5. Dennis, I'll get on that res chart today. I have a lot of test footage to shoot...whew. Better get started.

Feel free to fire any more questions my way.

Ah, the price of early adoption! We've been discussing the use of the Contax for a few weeks now, to supercede our spinners, and have both disc and cylindrical pager motors. My plan was not to use Quen's design at all, but to do it with an aluminum plate and the same bushings used to suspend cd player motor/slider assemblies. These bushings isolate the units, but can be tightened to reduce or increase compliance (vibration frequency) So Ben, your success makes spending the $100 bucks for an intensescreen a bit more palatable. I also have some concerns about z axis movement using this setup.

Due to my spinner design, I can't the cam close enough to test for vignetting (1.6") so I'll have to do this with another setup.

Thanks very much for your work posting your results. It's very much appreciated!

All the optics have been switched out.

Thanks Ben. I know you're using a Century achromat, but what PCX/Condenser are you using if not the one that comes with the Letus35?

I've posted a few questions here : http://pana3ccduser.com/showthread.php?t=7056

Michael, you don't need a PCXL when using the Beattie.

Does the Beattie show grain at all? I thought it was etched in concentric circles, without grain.

The Beattie has very, very little grain. It does have concentric circles, but on the fresnel side. The ground glass side is just a dull matte texture, like the Nikon D but much more refined.

Ben, how much did you pull the stoppers out? It looks like they are out all the way and being held my the glue - is this true?
If they are in slightly, how did you measure all four legs exactly so the FL?

Wow Ben, that's absolutely amazing. Nice work.

In light of this, does anyone know if Quyen would knock a few bucks off the price if I told him I didn't need the GG because I was just going to replace it with the Beattie anyway? I realize he makes these pretty cheaply as it is, but that would be a little less work (and expense) for him to not have to bother with it as he made it.

Not sure Joel. He sells replacement GG's at two for $10, I think. I don't really think it would affect the price that much.

Leo, I approximated a millimeter on each of the stoppers, and left them in the rest--they're not pulled out all the way. I was contemplating doing that though. I measured the distance from the plastic mount base to the edge of the slide holder with a ruler on each of the stoppers, making sure they were the same.

Very impressive. If you didn't use any external light for those clips, I'm stunned.

The G35 beta unit I'm using needs about 5k of light to light a small room without underexposing at f1.4 (to be fair, your images were a bit underexposed and the last was very underexposed). That's with a dvx. For close ups, I'd say 1000w of light maybe, unless you need the background lit.

That test clip was shot at f4 on a 55mm 1.2 lens. I was trying to keep more things in focus to show sharpness, I guess I couldn't opened it up more--I have zebras on, but I'm just not that good at judging brightness, I guess. I have more test footage on the way.

How much lighting were you using, though? If those were at f4, those results are pretty amazing.

Wow Ben, that's absolutely amazing. Nice work.

In light of this, does anyone know if Quyen would knock a few bucks off the price if I told him I didn't need the GG because I was just going to replace it with the Beattie anyway? I realize he makes these pretty cheaply as it is, but that would be a little less work (and expense) for him to not have to bother with it as he made it.


Well, that wouldn't be much of a difference as Ben pointed out. I would be more interested to know if he would make it with the Beattie in place if we paid for it. It looks like it's the best and maybe the only way to go.

Well, that wouldn't be much of a difference as Ben pointed out. I would be more interested to know if he would make it with the Beattie in place if we paid for it. It looks like it's the best and maybe the only way to go.

Indeed, that was my next thought as well. ;)

Dan Diaconu's been using a vibrating beattie in his MPIC, regarded by some as the best adapter out there for any price, for the last year or so. They do work.

Ben, can you comment on z axis movement at all with your setup?

Damn I can`t wait my Beattie to arrive, ordered it from B&H for two weeks ago for my open source adapter project I`ve been researching and developing for two and a half months for now.

Now I`m a bit concerned about that F100 Beattie`s size I ordered.
Will it still cover full frame?
I`m developing my design around parts most available in near future (Contax RTS II were discounted like years ago)
I assumed viewfinder coverage of those two SLRs mentioned to have clear Beatties were quite identical in size, 96-97% per specs.

OT: Ben how did you deinterlace that that sample video? I`m assuming you have GS400. Damn perfect diagonal quality... Or was it native progressive? (DVX etc)

Thanks,
T

Toenis, he is using a Canon GL2, as can be seen in his first pictures.

Ben, is it possible for you to shoot the same scenes you tried earlier with the thin-film screen so I can do a better comparison of light transmission, sharpness and distortion? I would greatly appreciate it.

can you comment on z axis movement at all with your setup?
I'm not seeing any. Plus I don't think there's much, if any, z-axis give in the Letus design.

How much lighting were you using, though?
My kitchen has two halogens over the island in the middle and a few 60-75 scattered around the place.

Ben, is it possible for you to shoot the same scenes you tried earlier with the thin-film screen so I can do a better comparison of light transmission, sharpness and distortion?
I was planning on doing that today. It's overcast just like it was when I shot with the bag. I'm also going to shoot an EIA1956 with and without the cam, which is printing out now.

Shot the outside footage today. It was a lot darker today than the other days though, so the footage will be slightly darker.

Also, the first few seconds show the image with the motor turned off, then turned on.

http://www.frozenphoenixproductions.com/misc/letus/beattie/testoutside.mov

That's all I got. EIA1956 tomorrow.

Thanks for posting that Ben. Now more questions:

1. What are we seeing on the right side of the frame? Did you need a bit more zoom?

2. The bokeh has a what I can best describe as a "buzzing" quality to it. I compared it to some footage from my spinner, both raw and 3K wmv compressed...and I don't get this. Is this just quicktime compression artifacting? Maybe you could post a few seconds of raw DV up on filefactory or something similar...particulary when the green grass is out of focus.

3. My guess is that you're losing little if any in terms of F/stops with the adapter vs without? Would 1/2 stop be a good guess?

Ha, you've got leaves, we've got 1 metre of snow! Great work on this :-)

Thank you Ben, looks very sharp!

1. Dennis, I have no clue what that is on the right side of the frame, but it isn't in the original footage. It seems to be an artifact of Sorenson. If anyone can shine some light on that...

2. I'm not sure what you mean by buzzing, but it looks ok on my monitor. Here's twelve seconds of uncompressed footage:
http://www.frozenphoenixproductions.com/misc/letus/beattie/testoutside_uncomp.avi

Won't be up for another 16 and a half minutes after this posting, so be patient.

3. The F-stop loss is small, but is still there. I'd estimate at least a stop.

Thanks for the comments. Keep em coming--I'll try to test what I can.

If you are going to an a4 size for your EIA1956 chart, use photo paper to print it on. The grey scale seems to come up better on that.

I also selected the photo option hich prints colour, again seems to print the grey scale better and the fine detail a whole lot better.

You may get a colour cast in the first copy as the printer settles down. My printer is the Canon BJC7100 which has seen a few hot dry summers which doesn't help inkjets. There have been some improved technologies since.

The MiniDV codec apparently apparently hits a wall at 530 TV lines but don't take my word for it.

Five micron AO dressed moving groundglass seems to be good for 710 TV lines horizontal res as MiniDV produces sharp artifacts from the pattern to about 710 when it blurrs them together.

Don't take my word for this either as my methods are instinctual, copy others and are not all that scientific.

Thanks for posting that Ben. It's hard to describe, but view the clip at twice normal magnification, then watch the bokeh areas. Picture a million little busy mosquitos. It may just be noise if the cam was dialing in gain, or something from the adapter itself. It's the fact that the noise is so "busy" that I'm wondering about.

Maybe some DV experts can ring on on this...

When you say 1 stop, is that with your F1.2 lens? Set at F/1.2?

Edit: Is that one of Dan's FF gears I see on your lens?

I noticed the grain as well, not sure what it is - in the uncompressed footage it is really evident, not in the mov footage though.

Ooohh...I thought you knew about that. That's the moving screen. What you're seeing is literally moving grain, the Intenscreen being vibrated.

I'm guessing a stop because that's about how much I have to move the aperture on my lens to compensate. On that topic--my GL2's lens is a 1.6, but in manual mode it'll only let me go to 1.8! And I know I've seen it at 1.6 before...anyone know why it's doing this?

And yes, that's one of Dan's gears on my 1.2. He offered it for free to five people under the age of 21 as a way of "supporting the young generation," and I accepted.

I'm guessing a stop because that's about how much I have to move the aperture on my lens to compensate. On that topic--my GL2's lens is a 1.6, but in manual mode it'll only let me go to 1.8! And I know I've seen it at 1.6 before...anyone know why it's doing this?

Ben, as you zoom in, the minimum f-stop you can use on the GL2 goes up. If you zoom out you will get back the 1.6. It's just how it normally changes as you change the focal length.

Yes, it’s the grain of the Beattie. It’s also apparent in some of Dan’s candle pics, even when the screen is moving.

I actually like the look...

I don't mind it, but I wouldn't mind getting rid of it either. All I would need to make it go away is a larger motor. Giving it more voltage will only increase the speed of the motion and decrease the radius of the oscillation. Less voltage does the opposite. It's a trade-off, and getting a larger radius without sacrificing speed just plain requires a bigger piece of hardware.

I've found the grain induced by the Beattie screen is most apparent on really bright lights that are out of focus. I'm learning how to make sure not to have that a distraction in my shots.

I've found that footage shown on a TV doesn't show the grain at all. But with us looking at it "under the microscope" looking for *any* imperfection, on our high resolution monitors inches from our eyes, and yeah, you'll see it.

As soon as the HVX200 arrives, I'll be able to test whether it can be significantly seen on HD.

But, in short, Ben, and anyone else using a moving Beattie element, to answer that age old question, "Are we there yet?" Yes! We are! Close enough! :)

I've found that footage shown on a TV doesn't show the grain at all.

I was about to mention that. On my CRT prod. monitor it's clear as day.

"Are we there yet?" Yes! We are! Close enough! :)

Thank goodness. We've spent enough money and time to get there...whew.

I enquired with a technical man about noise in small video camcorders.

Apparently noise occurs at a constant level. In bright conditions it is not readily noticeable. Apparently at lower light levels when some gain is applied, it still stays buried in the detail of the image, but is there.

When we create large areas of softness in an image with a narrow depth of field, we are leaving a space for any noise to make itself visible where it might otherwise be hidden by textural detail which would be in the image.

The "grain" you are getting may not be entirely from the groundglass.

There is reference above to aperture on the GL1 being set as wide as it will go. Is this necessary because of a gain problem with the GL1. If it is not and the GL1 is over-riding and using a higher shutter speed to limit the brightness, then the groundglass texture is going to get frozen and visible in the image.

My understanding of the Letus is that the excursion of the groundglass is small. Give there may be a stop and start cycle or a slow and fast cycle if the movement tends to be more linear than orbital, then with a higher shutter speed, groundglass texture may become visible.

All this may be very irrelevent in your situation however there are the thoughts.

If you are adding power in order to speed up or increase the excursion of the groundglass, would there be any future in adding some weight ballast to the groundglass frame.

Steve/Ben when you say "not visible on a TV" what TV are we talking about? I've found most everything unpleasant ends up visible on the my 51" HDTV. Worse when projected from an LCD projector onto larger screens. From my point of view, the microscope comes out, we post up footage, analyze, correct, then move on.

I guess after seeing the footage, I'm wondering if I should be abandoning my spinner for 1/2 stop gain over a spinner. The beattie should be perfect if rotated faster, but then you have the whole noise/vibration issue. I'll confess that this "noise", where ever it's coming from, is very distracting to me...and I noticed it right away. I'll also confess that noise/grain in general drives me crazy. Steve is right though in that we are much more critical of these aspects than the average observer.

Hmmm. Food for discourse. And just another reminder that as Scottie says "Ya cannot defeat the laws of physics Captain".

There is reference above to aperture on the GL1 being set as wide as it will go. Is this necessary because of a gain problem with the GL1. If it is not and the GL1 is over-riding and using a higher shutter speed to limit the brightness, then the groundglass texture is going to get frozen and visible in the image.

Well, it's a GL2--and all of the test footage has been shot completely in manual mode at 1/60 shutter, so there's no overriding going on. Grain becomes apparent pretty fast as soon as you start getting up into the higher shutter speeds.

Yes, there's inherent noise that comes with video, and party that's why most people are willing to accept noise that comes with shaking the Beattie. I guess I am.

And not to change subjects, but I just finished filming a scene of a movie I'm doing and I realized that it has very little to do with what you record with, but rather who you're recording. Acting draws people into the story, not depth of field. Good acting and shallow depth of field is quite a dynamite combination though. :)

Exactly! I was entirely excited when I saw my first adapter footage. Video obviously doesn't give nearly the same opportunity to draw the viewers interest to the "focal" point of your frame. I actually grabbed a few stills from the GS400 while the adapter was attached and got the old familiar SLR look, albeit at 4MB (well, really closer to 2.5MB). Very cool...a digital SLR, minus the 8MB quality.

When you get immersed in this subject, it's easy to forget until your wife walks over, looks at the footage, then makes the comment: "You did all of this to get that???" Lugging the 100lbs of blast media in five different grades into my shop (GG tuning), I wonder myself sometimes!

I severly doubt that any casual observer would pick out the grain Ben. My thanks for all the work you've shared.

Acting draws people into the story, not depth of field. Good acting and shallow depth of field is quite a dynamite combination though. :)

Yes, this is more of what I like to hear around here, in addition to all the tech talk. In addition to "acting" I'd say "performance" is key, whether that's captured reality, abstraction of reality, or scripted work. But I think production talk only happens when we're finished with hardcore R&D mode.

Congratulations Ben. Be sure to post more footage of your work.

"When you get immersed in this subject, it's easy to forget until your wife walks over, looks at the footage, then makes the comment: "You did all of this to get that???" Lugging the 100lbs of blast media in five different grades into my shop (GG tuning), I wonder myself sometimes!"

or when your girlfriend finds all the melted wax on her things .. or her hairdryer overheats and burns out, and destroy every cellphone in you house trying to find a vibrator that will work, or you cut your fingers wide open trying to get glass out of a filter and she looks at you and your bleeding hands in horror as you hold your fancy looking frankenstein adapter.. taped together for quick changes sake.. and "ALL" you have to show her for your efforts is "a blurry background :P "

G35 footage by Matthew Wauhkonen :
http://csxinfo.net/mattw/g35.mov

Modified Letus footage by Ben Winter:
http://www.frozenphoenixproductions.com/misc/letus/beattie/testoutside.mov

Both have the buzzy grain. Both have very similiar results. I think I prefer Bens footage over the g35. Hmmmmm

Ok if the grain is there with both the old and new GG. Should one still consider replacing the GG with a new one? Or is what we are after is the Crispness of the image that is in focus?

Craig, by replacing the GG with a Beattie there is an increase in clarity as well as a decrease in light loss, which are the main reasons for the switch.
Both have the buzzy grain. Both have very similiar results. I think I prefer Bens footage over the g35. Hmmmmm
Don't forget that the G35 is built to be much more durable than the Letus, as well as the fact that the G35 is apparently static...but then again, is it worth the extra $$$?

Removed duplicate

I think I prefer Ben's to the G35 as well. I wouldn't even complain about that amount of grain, since it gives it kind of a film-y look. Since the G35 is static, I suppose you could concievably get almost zero grain out of it by making a grain filter in post (since there's so little as it is), but for my part, I like prefer the very slightly grainy look of Ben's.

Ben, did you have any luck with the EIA1956s with and without the adapter? For my tests, I left the tripod in place, just removed the adapter and reframed with the same f/stop settings (increased shutter speed after removing adapter). I'm very curious! It would be great to try this with the letus GG too, but that's a lot of work.

Well, for another day yet again I have been unable to do the EIA1956 test. But I did try quickly shooting a grid and I noticed that there is some slight barrel distortion, which makes me sad. It's probably the Century Optics macro acting up in this situation, which makes me wonder if my previous "shortened" design is still a better way to go. Still, I have a lot of footage to shoot tomorrow for an actual TV class project so we'll see how the footage looks, I'll post some tests. And yes, I promise I'll get around to the EIA1956, it's sitting on my desk right now :)

Ben, I am noticing this too with my rig, and it is bothersome. I think Wayne was saying there is a sweet spot for the macro to be in so that there is no barrel distortion? Maybe it was him?

The distortion is most likely coming from the PCX lens in the letus. The SG35 also suffers slight distortion.