Couple more things. Have people had more success with the GG near the lens, or near the DV camera. People seem to be doing different things here too. I would have thought you'd have to have the GG the same distance as a 35mm image place to get the correct DOF, otherwise you'll be getting more or less than real 35mm.

People are putting the GG in different places because that's where they are focusing the image, that's all. It doesn't really matter where the GG goes in the adapter as long as you can get the SLR lens to focus on the GG and the DV camera to focus onto the GG. You may want to do it so that focusing would be more like properly focusing an SLR lens for the right distances, and that would take more work than the simple ad hoc solution that some people are likely taking here.

And, couldn't you just build a long adapter so that the GL2 can focus on the plane or is that still not possible?

Of course, but the longer you make it the more unwieldly it will become and the less likely you are to be able to use it handheld anymore. Also, it will be harder to keep it aligned properly unless you have supports.

Ok, i will clear this doubts for once and for all..


The magnifying glass goes between the GG and the DV camera, and the GG has to be as close as possible to the DV camera until there is no vigneting.

Dont get confuse, and the best way to solve it is to find a cheap wide conversion lens, and take the first lens that indeed maginfy and a lot... that will cost ya like 35 bucks... dont find and expensive one and also you dont need one that have the exactly the same diameter, cause you zoom half way in (my camera case), so you can find a cheap wide conversion lens for any cheap dv camera, and just use the part that you need.

Keep it simple, and you will get better results :)

OK i'm jumping in I have a done a "dry" test; frosted glass, nikon lens, XL1 and a cardboard box. No fresnel or mag glass. No moving parts I want to get a feel for everything before I move on. It really works I'll have some stills later.
My main question is, in the mini35 what all is handled in the relay lens section? How are they over coming the 7.2x magnification of 35mm lenses and 1/3" CCD's? what could we use in place of this my goal is to replace the 16X lens of my XL1 to reduce the amount of glass the image is coming thru.

great jorb Agus, when are you posting your plans?

Luke

Well, this design basically depends on the camera lens being
in place. The XL1 is a difficult camera if you want to remove the
lens because you will have to replace it by a "relay" lens.

The 7.2x magnification is gone because the image is projected
onto the ground glass (the CD) instead of on the CCD directly.

<<<-- Originally posted by Agus Casse : Ok, i will clear this doubts for once and for all..
Dont get confuse, and the best way to solve it is to find a cheap wide conversion lens, and take the first lens that indeed maginfy and a lot... that will cost ya like 35 bucks... dont find and expensive one and also you dont need one that have the exactly the same diameter, cause you zoom half way in (my camera case), so you can find a cheap wide conversion lens for any cheap dv camera, and just use the part that you need.
-->>>

Agus,

Just to be clear, when you say "wide conversion lens" you are talking about a Macro lens? And, you don't have to connect it directly to the camera? Could you explain this....because I think that would be a great way to connect it - put on the macro lens and there you go!?!

Thanks,
Clay

<<<-- Originally posted by J. Clayton Stansberry :
Just to be clear, when you say "wide conversion lens" you are talking about a Macro lens?
Thanks,
Clay -->>>

What Agus means is that inexpensive Wide Angle lenses have a separate Macro lens attatched. Simply buy a cheap combo, and discard the Wide Angle portion, and you have a Macro lens all by it self. SEE:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2970304852&category=29964

As you can see in the description and photo is states "With Macro". You can see the ring on the bottom of the lens that reads MACRO.

Hope this helps,
Spence

OK more discussion on the XL-1 conversion.
if the 7.2x magnification is no longer an issue then would it be possible to get say a xl1 to nikon adapter and a good macro lens for your relay? What other issues would need addressed from the GG back to the CCD. Is the relay also flipping the image or is this handled by mirrors inside the unit.

Thanks everyone keep up the good work.
Luke

To test your relay lens options, take your camcorder along to the place you intend to get your relay/close-up/macro lens from and ask to be able to test one.

Take with you also, a test card or probably better, a translucent panel, with a frame drawn on it, the same size and shape as the 35mm image frame. On this frame there should be drawn a grid of parallel black lines, horizontal and vertical, at least eight each of even spacing, thickness and opacity.

Look for in the pattern of lines :-

1. Distortion. ((II)) = barrel distortion ))II(( = pincushion distortion.

2. Variations in sharpness across image, most likely to be apparent in corners or sides.

3. Variations in color across image.

Retailers, if co-operative at all, may only allow you limited instore testing opportunities of the quick and hand-held variety with a salesperson impatiently hovering.

If you are going to be handholding something that does not fit your camera, up to your camera lens to test it, cut yourself a short straight length of wood for a jig, with several holes bored down a straight centreline marked on it. This is to mount your camcorder on at one end so that you can hold the added lens and image target in a steady relationship with the camera lens by bracing down onto the wood or even sit the object on it if it won't fall over. You'll some small scraps of ply or cardboard for packing so you can get it centred vertically.

Also improvised testing itself may introduce an unequal distortion or variation of focus across the image. This will be apparent on one side or upper or lower edge of your test image.
Deficiencies in your intended lens setup will most likely be equally represented in quarters of of your test image provided your added lens is centred on the centre axis of your cameras own lens system.

There is a caveat to all my babble here. With some camcorders, the centres of the tripod mount hole, and centre axis of the lens system do not co-incide. With some camcorders, the centre axis of the lens system does not fall in the centre of the CCD array. This may be due to design or variations in build quality. With my PD150 (PAL), the lens centre axis and tripod mount are off-centre by about 6mm. The tripod hole cannot be used as a centre reference. My PD150 lens centre axis is also offset slightly to the right as viewed in the recovered image (to the left in reality).

Some of the Iraq night-vision images framed wide for best subjective resolution (circular image inside the frame) have the same offset my own tests showed, so it may be a characteristic of the camera.

For the same reason I had to dress the left side of the optical path through a 16:9 adaptor to eliminate left edge cropping on fully wide.

This is probably a lot of useless info for most. Feel free to add to, criticise and correct where necessary.

I also thought about using something instead of or on the CD. I work in a theater and we have plenty of gels laying around as well as diffusion.

Gels are cheap to purchase and I thought either Rosco or Lee made a solid sheet version, but I can't find it right now. The diffusion comes in different strengths and patterns and is quite consistent.

If you contact a theater supply store you can request a (usually free) swatch book containing small samples of different gels, diffusions, etc.

<<<-- Originally posted by Luke Andrews : OK more discussion on the XL-1 conversion.
if the 7.2x magnification is no longer an issue then would it be possible to get say a xl1 to nikon adapter and a good macro lens for your relay? What other issues would need addressed from the GG back to the CCD. Is the relay also flipping the image or is this handled by mirrors inside the unit.

Thanks everyone keep up the good work.
Luke -->>

Yeah I suppose you could, but it would be cheaper just to get some form of close-up adapter I imagine.

Also if you have an XL1 you can just turn the viewfinder upside down by mounting it backwards, if you see what I mean.. It's not ideal, but it's cheaper than any other solution and there's no loss in image quality.

kieran

Update:

Went over to best buy where they are selling a very cheap cd player/discman for 17.99 with a 5 buck instant rebate... so 12.99 plus tax leaving the store. Took this thing apart with a srewdriver and found that the motor that spins the disc can be completely seperated from the rest of the board and stuff... giving you the red and black wires off of the motor in which to hook up to a battery pack (which you can get at radio shack... I have a 2 triple A pack.) In between I also have wired a on off switch (also from radio shack). And believe me if I can do this... anyone can because I don't know crap about electronics. This is also the best way to do this thus far. The radio shack toy motors Agus reccoments make WAY too much noise, not even usuable with a boom, and vibrate WAY too much (that could be fixed with a stable design but why not just spend the extra 10 bucks and get the cd player motor and you won't spend endless house trying to center the cd on the toy motor and kill yourself when you realize the shots look great but you'll never be able to reccord dialogue with a device using that motor). So believe me... use the cd motor!

I am using a wide angle adapter I had (minus the wide lens like agus is doing) for my trv20 on my sony pd150. Problem is that you must zoom in a little to get away from the vinnetting of the actual lens. I went to NEWTONVILLE CAMERA looking for a macro lens and first off the clerk on the phone told me this adapter was not possile and tons of people were coming into his store recently buying and returning lenses, no one ever successful. I went there and proved to him that it does indeed work, however he was unable to produce me a 58mm threaded macro lens that would work with this device. (he had some macro lenses but they went out of focus before you could zoom out the vinnetting.)

I also managed to remove the motor from an old, broken CD player I had--only broke a few weeks ago, too, good thing I didn't throw it out! Stripped the wires, tapped 'em to a AA battery, thing spun up just fine. Best thing is, since it's a portable player, it has the little springy-ball "clip" style spindle. Holds the CD in place without glue, and spins at a nice speed (I think).

Now I just gotta get the equipment necessary to mount this bad boy to my VX2000, and the means to attach a lens to the front, and I can finish this project.

Peter or Robert, what was the model of the cd player or is it just any old cheap discman? I might buy it today and finish my version of the Agus35 using 35mm film cans by tonight. I already got an image and i just want to better stabilize the system by using another can before i post pics. I'm using tiffen macro lens +1, +2, +4 combined for a +7 for $39 at a local photo store. It worked out fine, but it seems using the cd motor might be the solution to the vibration sound problem.

For Peter Sciretta. - I used a generic 42mm eyepiece of chinese origin to fit Tasco telescopes, extracted the lenses to make up an adaptor from PD150 to PNP-HG night-vision intensifier. This frames the 18mm diameter display tightly top to bottom when the zoom is wide and corner to corner at about 25% in. It wouldn't be any use for the 35mm image frame size but a lower power two element lens set of similar design might.

In my early prototyping I used a similar less powerful lens set in a sub-assembly out of a Sony VCR16B telecine adaptor (a 16mm C mount lens, a macro spacer, a mirror, a ND filter and the two lenses in a module, all enclosed). This framed closer to the 35mm frame size and needed a lot more zoom to come in to frame onto the 18mm diameter display tube target.

There might be some benefit in experimenting with 90degree consumer telescope eyepieces and barlow lenses. I think the eyepiece lenses may be too powerful, but there may be something there - just a thought.

Both of these lens sets I describe do not erect the inverted image.

Just to tie some loose threads:

Agus's sugestion of finding a "cheap wide angle" with macro is fine, but you have to be sure you're getting one large enough for your lens's threading. For the GL1/GL2's out there, a good choice might be this one (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2970527767&category=30069). Not sure if the VX2000 has the same threading...

CD motors are great design choices -- they're so quiet.

Uhm, that's it for now.

- jim

For those using a CD motor - AWESOME! I am glad it worked. Could you tell me how far you are putting the CD away from the lens, I mean are you having to extend it out very far (I know this will differ for different cameras, but I am speaking in general). And, if you are, how are you doing it? I will be making the trip to Best Buy soon...thanks for the info Peter!

Clay

Peter -

In answer to your question about the telephoto lens adapter ... the slide on the bottom of the support has a screw to adjust the length of the arm. So you'd have another 6" extension that you don't see in my photo.

Sorry for the lagged response (been very busy during Christmas season). Can't wait to get back to work on this project.

Richard

Ok. im a little confused. I'm trying a very basic test version of the agus35 ..... i have a box ...a vivitar lens. ....a piece of ground glass (clear cd rubbed with sand paper) ....then i have my gl2 lens in the other end of the box. ....i can see the image being projected onto the GG. ...and I can focus on it. .......But heres where I'm lost ......You can see the projected image just fine ...but if you look PAST the ground glass ....you can see the light source from the vivitar lens ...which is much brighter than the light that is hitting the GG. ........So when the gl2 is focused on the projected image ...you can see this dime sized ...bright circle of light ...coming from the lens ........how do you get rid of that? .....Do you have to zoom into the dime sized bright circle area? ...I cant imagine that ....because it is such a tiny area. .... ..................maybe im totally lost ......

any ideas??


thanks,

chris

Chris, I think you're right and you have to zoom. I've heard something like this mentioned in this thread before. That's why I think you really will need a macro lens etc, to be able to focus that close.

Aaron

.....chris......do you have the.....apeture wide open?.....as i understand it......haven't made one yet....you lose a lot of light........make sure apeture is set at it's most open position.....lowest number......1.8.....or something like that......

If you can wait for shipping here is one

http://www.bestbuy.com/site/olspage.jsp?id=1062198077800&skuId=5726191&type=product&productCategoryId=cat03058

I have been getting all my materials together to build an Agus35 with a DVX100. I bought a 30 pack CD spindle but I am not sure where i should place the spinning CD. Would it be better to place it by the Camcorder lens or the SLR 50mm lens? Should you place the CD as close to the lens as possible?

Ok folks ....i have some test video ...from a very very basic agus35. ......Let me just say that .....the video example is very poor quality. ....nothing at all like agus' videos. ....This is strickly a test.


www.elpez.com/agus35test.mpg


Here's what I did. ...I took a cardboard box ...cut a hole in each end ....stuck my vivitar lens in one end ...and the canon gl2 in the other end. ....i slit a hole in the top ....and stuck a sand papered clear CD in the top ....then i just shot some video. .......

A few notes

Lighting is definitely a problem ....As you can see ...it was very dark ...and I had the settings cranked up pretty high in the gl2

Another thing .....Agus recommened using 600 grit sandpaper ....I didnt have 600 ....so i used 150 .........as you can see it puts huge scratches in the CD ........Also .......as you can probably see ....the CD (ground glass) ...is not spinning. ....

Aaron ......I posted a question about the round bright spot .....I fixed that problem ..... ..I hadnt sanded the CD enough. ....I took the CD out ..sanded it some more ...and that ...essentially diffused the bright round light.

Hope i didnt offend Agus by constructing such a bad test agus35 ...

let me know if you have any questions or comments


chris.

<<<-- Originally posted by Louis Grimaldo : I have been getting all my materials together to build an Agus35 with a DVX100. I bought a 30 pack CD spindle but I am not sure where i should place the spinning CD. Would it be better to place it by the Camcorder lens or the SLR 50mm lens? Should you place the CD as close to the lens as possible? -->>>

it depends on your lens and camera, like mine is 1 3/4" away from the 50mm ans 3/4" away from the camera.

Just experiment untill you get a clear projection on the gg.

hehe...I guess I better let the cat out of the bag now- (mine is adjustable :) I will post some pics of my setup in a while.

John,

Great freaking idea!!!!! Adjustable, perfect. I think I am going to lay off awhile, waiting for all beta tests to yeild the perfect final result. You guys are awesome!

Clay

posing a thought ...and asking a question ....

isnt there some sort of material out there ...like wax paper .....that you could put in the place of the GG ........like ..the translucent screen in an SLR camera. ......that way ..you could have a clean enough image ..without having to spin the projection screen (ground glass)

my question is ......what percentage of the original picture ...(720 X 480) are you losing.......by zooming in to the image close enough to eliminate vignetting.

for exampe ...are you ending up with ....a 680 X 420 image?? ....


chris

OK I'll take a stab

# 1 even a very pure frosted (Wax Paper) type substrate is going to have issues because your taking 24-30fps it going to look like your filming thru a screen because the grain will not change overtime, unlike film who's grain is organic like due to changing it's pattern every frame. at least thats my take on it.

and #2
your not losing any resolution because you have not hit the cameras CCD's yet they are going to take a 720X480 sample of what ever they see.

I'm working on my plans right now, I really look forward to seeing what everyone comes up with.

Luke

heres my version,

im still experimenting with having to zoom slightly. I think that I can get the camera closer to the gg.

the gg is adjustable by moving the fan frame along the guide bolts.

I have a fresnel lens 1/8" away from the gg mounted on guitar wire.

I am using a Sima wide angle lens that I got at Bestbuy for $30 then removed the WA lens portion leaving the macro in place, If I just move the cam 1/2" closer I have a great picture without zooming, but I dont have a good way to secure it properly so I left it alone for now.

I also noticed that the final image is very dark, I might need a lighter gg

http://www.imagestation.com/picture/sraid92/pca37d824a102290f6a018832f9788a14/fa531005.jpg

http://www.imagestation.com/picture/sraid92/p13887b61f0791cf595427ac76b863548/fa531004.jpg

http://www.imagestation.com/picture/sraid92/pd377ca006084d6c60555434c2779084c/fa531009.jpg

http://www.imagestation.com/picture/sraid92/p903d9d22a9eca56f659aef6ea5db817c/fa53082e.jpg

http://www.imagestation.com/picture/sraid92/pdca90aa84d2b4e2aabf3b86f7bc002c8/fa528f0c.jpg

gaspain

Interesting. VERY interesting. I may have to steal your idea of using the fan casing when I make mine. And is that a fresnel lens in the shot where the CD is off?

<<<-- Originally posted by Jon Yurek : Interesting. VERY interesting. I may have to steal your idea of using the fan casing when I make mine. And is that a fresnel lens in the shot where the CD is off? -->>>

ya thats the fresnel, im still unshure of the proper distance away from the GG, rit now its about 1/8" away (1/4" would be better)

Im pretty happy with using the fan. Its quiet and smooth. I used a part from an old DVD player to hold the CD, gluing that on center of the fan was a pain to get it centered. I also had to trim alot of plastic of the shroud with a mill so the GG wouldnt rub.

<<<-- Originally posted by John Gaspain : <<<-- Originally posted by Jon Yurek : Interesting. VERY interesting. I may have to steal your idea of using the fan casing when I make mine. And is that a fresnel lens in the shot where the CD is off? -->>>

ya thats the fresnel, im still unshure of the proper distance away from the GG, right now its about 1/8" away (1/4" would be better)

Im pretty happy with using the fan. Its quiet and smooth. I used a part from an old DVD player to hold the CD, gluing that on center of the fan was a pain to get it centered. I also had to trim alot of plastic of the shroud with a mill so the GG wouldnt rub. -->>>

Originally posted by John Gaspain : heres my version,

im still experimenting with having to zoom slightly. I think that I can get the camera closer to the gg...

Very cool. I'm using that same box housing from Radio Shack, but my design isn't nearly as industrial.

For those of you using the CD motor -- I noticed my portable CD player uses two "AA" batteries. Would upping that to a 9v stress the wiring or motor itself?

Also...my latest trip to Home Depot had me looking over the sandpaper section. I've already used 150 on my GG, and 600 was nowhere in sight. Agus, and others who've experienced success with their design -- can we see close-up, clean shots of your GG?

- jim

On my trip to HomeDepot the finest grit sandpaper I could find was 400 grit. It seemed to work well.
Mike

If not using sandblasted or chemically etched glass, I would be inclined to get hold of some 600 grade lapidary grit (silicon carbide), clamp two clear CD disks back to back with a firm seal around the inner hub and outer diameter edges, put a bunch of bearing balls into a gemstone tumbler barrel with the grit and water, turn it on and leave it to its own devices for a few hours.

As long as the two disks have not moved against each other or grit got in between them, you should end up with two clear disks with a translucent surface on one side and smooth on the other.

I would do only one pair in a barrel at a time as sliding edges will cause long scratches not short pitts.

Just a thought.

i am using 2 AAA batteries (1.5 volts each) on the cd motor and I think thats going too fast and making more noise then it should... not nearly as much as the radio shack kiddie motors but noticable noise... any suggestions?

BTW: What project box size you guys using?

Bob, you're actually close to the mark on how to create real ground glass. You basically take the grit, add a bit of water, and rub two pieces of glass together for about 20 minutes. Using that method you can create better-than-professional-grade true GG, if you take your time at it :-)

paulb

<<<-- Originally posted by Peter Sciretta : i am using 2 AAA batteries (1.5 volts each) on the cd motor and I think thats going too fast and making more noise then it should... not nearly as much as the radio shack kiddie motors but noticable noise... any suggestions?

BTW: What project box size you guys using? -->>>

7x5x3, its takes a bit of heat to make the GG fit without rubbing

what do you mean by heat?

may burn the motor out if it doesn't it will spin REALLY FAST!

I took the motor/CD holder out of an old portable CD player, snapped a CD into it and connected it to 3v. WHOA! It spins too fast. The gyroscopic effect was very pronounced and I was concened if my"Agus35 Mark 12 Pro Rev 1.0" was jerked to quickly the CD might come of holder!

I then connected it to a single 1.5v cell and its much better. It still spins at a good rate.

Tom

<<<-- Originally posted by Peter Sciretta : what do you mean by heat? -->>>

fire, use a mini blow torch or windproof lighter to melt the inside of the box to fit

by fire/heat what exactly did you do to the box because i have the exact box and can't figure out how to make the lens fit?

<<<-- Originally posted by John Gaspain : <<<-- Originally posted by Peter Sciretta : what do you mean by heat? -->>>

fire, use a mini blow torch or windproof lighter to melt the inside of the box to fit -->>>

www.elpez.com/agus35test.mpg linked

Here are two pictures of my quick-and-dirty attempt to make one of these things. It works! Now I'm going to spend a few dollars and make a nice one.

The lense was biult into a 35mm camera and by the time I wrestled it out it could no longer be focused. I changed the motor on it and had to mount the lense backward to get it far enough from the GG. The big gash in the side is from only having 100 packs of CDs and having to cut a huge hole to shove my camera into.

http://vistatheater.org/~rhenry/agus35/agus35-1-front.jpg
http://vistatheater.org/~rhenry/agus35/agus35-1-side.jpg

For those looking for fine grit sandpaper, try the auto parts store in the paint section. They usually have really fine grit wet/dry paper for doing touch up or other paint/body work. I have gotten 1000 grit at auto part stores before. They should at least have 600...

I added an adjustable fresnel lens

http://www.imagestation.com/picture/sraid92/pdca90aa84d2b4e2aabf3b86f7bc002c8/fa528f0c.jpg

edited to say: HELL YEA! thats what i needed! its adjusted out a little over 1/4". This fixed any vignetting.

John,

A couple of questions:
1. Where did you get the freznel lens?
2. Where did you get the fan?
3. Is the box the one from Radio Shack?
4. When are we going to see some footage with the fix?
5. Plans?

Agus,
How are your plans coming?

Thanks in advance...
Clay

Hey John, what tool did you use to cut such perfect holes in the box?

<<<-- Originally posted by J. Clayton Stansberry : John,

A couple of questions:
1. Where did you get the freznel lens?
2. Where did you get the fan?
3. Is the box the one from Radio Shack?
4. When are we going to see some footage with the fix?
5. Plans?

Agus,
How are your plans coming?

Thanks in advance...
Clay -->>>

1-Walgreens $1.50
2-computer store
3-radio shack
4-I need a better GG, so in a while
5-Just look at the pictures for now

<<<-- Originally posted by Paul Bettner : Hey John, what tool did you use to cut such perfect holes in the box? -->>>

I used a hole saw attachment on my milling machine, a drill should work tho