Paul,
The extinction resolution between the straight and through adapter framegrabs are not comparable because of the difference in framing.

Alain, if you fill both the entire CCD capture area with the entire resolution chart (you're zoomed in too much at the moment) you'll have a far more realistic gauge of your cameras resolution and the loss through the adapter.

The arrow points on the edges should touch the edge of the framegrab.

Brett
 

Yesterday I change the magnification lense for a lense that I took from a old super 8 camera that I have sacrifice,(Shame on me), whitch is 50mm and the first test was from one lens only,like I say before I tough that the two other element are not a obligation,but yes it is , and the secon is whit the three element.
So yes it's just magnifing lens.

maybe I should post a photo of my working space , it look like sacrifice table.)

The resolution chart is whit the whole adapter.

I am starting production on a short film in 2 weeks and would love to use this with my PD150. Is there any way I can pay someone to build me an adapter cheap and quickly?

Does anyone have plans to post a tutorial on this? I have seen the images of the Aldu35, yet was wondering if there could be some instructions put with that. Also, this may have been discussed in the other static thread but, how do you determine distances of lens, GG, magnifier, etc? Aldain, the footage looks great! Looks like I am going to have a collection of A-35's...an agus35 already and looks like I'll have to build one of these too! Thanks for all the work everyone!

Clay

I'd like to second the request for tutorial, I'm a little lost on the technical aspects of this and how it all goes together.

The distances needed are the same for the Agus and Aldu -- you just need to setup proper flange focal length and get your ground glass within a reasonable distance from your video camera's macro lens so as to afford it enough room to zoom in and fill the screen with the projected image.

That's it.

I don't have the time/money/energy at the moment to put up a tutorial on a static solution, but plan to when the time comes (if no one else steps forward ahead of me...)

But, basically, you've got 5 objectives with this project:

1. Get a macro lens or macro filter setup for your DV camera that is +7 or greater.

2. Obtain properly ground glass, or similar material.

3. Assemble a light and dust-proof housing that attaches your adapter to the front of your DV camera, and can accomodate your ground glass, with a mount for 35mm film lenses at the front. I'd suggest making a trip to Home Depot and looking at the PVC they've got...

4. Place the ground glass at the proper flange focal length from the rear of your 35mm lens.

5. Figure out a way to attach the setup to your camera.

Should be even easier than building an Agus provided you outfit yourself with the right materials.

- jim

step 2a- (addendum) I believe Alain used a clear UV filter, and ground that down to a GG.



Thanks for the summary Jim

Possible Breakthrough
 

I may have found something that works. Last night I found plastic holders that you put your negative pictures into. If you hold them from a distance of something you can't see through it, but if you place it right on something it's clearer than tracing paper. I used it and it seemed to work fairly good. I think someone else should try it though, because my adapter isn't built very good and is hard to line up the 50mm lens correctly (it kind of sags down a bit. Hard to explain).

Anyway, this very thin plastic has no grain, but you'll want to keep it in the best condition possible. It's a semi opaque clear plastic material from a distance (if you hold it up to your eyes and put your hand about 6 inches away, you'll barely be able make out what' you're looking at), but looks highly tranparent the closer you get to the object (hold it up to your eye put your hand real close and you'll see it perfectly. Place it on letters and you can see them almost as good as looking at them without the plastic covering them, move the plastic a couple of inches above letter and the letters will virtually disappear).

Try it. This stuff came from "Longs Drug Stores" and holds your negatives.

Corey: I know exactly what you're talking about. Didn't think of that. Good idea!

My aluminum oxide should be here Monday. I'm really looking forward to trying to make a ground glass. However, I'm going to try the route of starting with 600 grit and grinding the whole thing with just that. I know it'll take a while, but hopefully I can get some acceptable results.

As with others, I will post some images as soon as I get something going. I must say that I am a little worried now that I realize I should have an achromat/diopter, and they cost way more than I was expecting.

Also, are any of you working on an adjustable version, to accomodate lenses with different flange focal lengths?

Hey guys do you think having a 30mm by 20mm gg will result in a significant field of view loss? I asked John Jay about it he said that it is possible to gain back the field of view by using a 35mm instead of a 50mm slr. I was wondering about the barrel distortion on the 35mm is it very noticable? Also does anyone know where i can find a fast 35mm and a 50mm lens with the same threading size. I am thinking of using zenit's b gg for this adaptor which is around 30mm by 20mm.
All comments are very welcome.

Corey

The idea about the plastic was great. As soon as I read that I went looking through my old photos and found some to try. The image did look great on the plastic, nice and bright and sharp. But even with my little Sony TRV-11 I could definitely see grain and imperfections in the plastic.

Great idea though.

also we want to try and stay away from plastic as a GG because its not very good at light transmition, like the plastic GG's in the Agus35. I had to turn the gain almost all the way up for a 'normal' image, u just loose too many stops.

Glass is BETTER!! the Alain35 is proof of that.

Actually...

Knight Optics claims their plastic diffusers are better transmitters than glass.

I've written them an extensive email inquiring about the plastic diffusion screen's optical properties. Here's to hoping it's worthwhile.

- jim

I'd like to compile a gallery of everyones projects for quick reference.

So if you need your images hosted somewhere and you'd like to add to this compilation please go to the galleria

http://www.visionengine.com/galleria

Everyone interested in having a static adapter built--

I've contacted a Chinese optics company about having these built once an 'official' prototype has been nailed down. If we can put together all of the detailed requirements, they will more than likely be able to build a quanity of them (they're waiting for the details and quanity). So . . .if you're interested in getting in on this for the cost of having them built, shoot me an e-mail with your name and camera type. I'll keep a tally and let everyone know the price they give me once everything is finalized. I'm not looking to make a profit on these at all, I just want something built professionally as I'm sure most of you want as well, and we can get the price down the more we order.

I'll also need an official specification. Whovever wants to provide that can send it to the company directly. Just let me know and I'll provide the e-mail. That way, whoever provides the spec can work with the company with whatever questions they might have. Alain-- if you end up being the one to provide the spec, let me know and I'll help you clean up your english. :)

Any thoughts on this? Feedback would be appreciated.

Oh, a couple of issues that I just remembered, is there a way we can make pretty much the whole adapter standardized for different camera types (except for attachment rings)? Also, do we want to include a 35mm lens in the orders, or do we want to be able to add our own? If we go the "add our own" route, what ring adapters should be included?

I think the 35mm lens should be left out as many of us already have one we could add. Having one in the price would greatly increase the cost. Stepping rings are again something that can be cheaply added seperately. I think just having the base unit made to a good standard would be enough. More importantly is some kind of supprt/rail system for it.

Todd,

as people reply to you they should be sure and mention for what camera they want it for and I guess maybe you should have a tally of what cameras are and the numbers of each.

Good idea, Kevin. Please be sure to include camera type in your e-mails.

Simon, I tend to agree. The only reason I mentioned the 35mm lens was because this company already manufactures them and I think they are pretty cheap. I'll get a price with/without just in case someone needs one.

Rods/rails will be very important for this and we'll want to inlcude rods support in the official design.

Ah well, if they do good lenses it might be worth it depending on the cost. Further to my email to you, I use a Canon XM1 (GL1)

Well the simpler the design the better and the cheaper to make. Perhaps we should pick one lens mount (I vote Nikon F mount) and just allow the back of the system to have a big hole you can point the DV camera lens into. We add our own macro lenses, ect. Give the unit a tripod threading at the bottom and we can find our own ways to mount the unit and the DV camera together.

Sort of a half built project when we get it and then we adapt it for our own cameras. I think that would be the best way to ensure it works with everyones camera no matter how big or small they are.

Just my opinion

Mike I think this is a great idea, as each camera will require it's own rail and macro lens system.

Here is what I built in the meantime, its a rods system for my cam.

Now I need a matte box and a finished Alain35!

http://www.aequantum.com/images/rail5.JPG

I think that the part where the camera goes in needs to be able to have, for example, a 58mm (or whatever the largest camera size there is) thread that we can screw our own step down ring to. Otherwise if the camera is just sticking through the hole a load of light is allowed to leak in ruining the picture quality.

Simon, the possible problem with that is the DVX100 has a 72mm lens diamater.

Just a thought. Has anyone looked into magnifying the image before it hits the ground glass? Like using a larger ground glass and magnifying the image to say three times it's normal size. This would seem to solve a couple of issues. If the ground glass image was bigger the ground glass wouldn't have to be as finely ground as Alains is. There would also be need for less powerful macro lenses on the DV camera.

I assume it wouldn't be as easy as sticking a magnifying glass between the 35mm lens and the ground glass. But why not?

Mike--

Nice thought but at what point does the projected image begin to bleed over the sides of the ground glass? For those who have a mock-up already, is there a way to tell the size of the image you are getting? And what about the fresnal solution on the Agus35?

And as far as the 72mm on the dvx100, we might have to make one adapter for dvx owners and one for everyone else . . .

Yes, the DVX-100 is a big problem. Perhaps if enough DVX owners can get together they might be enough demand to make 2 versions?

All dvx owners should also check out the advances on this project at www.dvxuser.com. Go under the "cinematography" thread followed by the "mini35" thread.

As far as magnifing the 35mm lens' image before its projected on the ground glass...I wish it worked that way but apparently doesnt. In doing so you will change you the DOF characteristic of the lens in a negative way. If one could just make it larger without a effect then a even better solution would have been just to make it smaller instead so that the image project straight on to the camera CCD instead of the ground glass (in the case of the XL1). But if that worked P+S Technik would have never gone through the trouble of using a intermediate image/ground glass system. Optically I dont know why this happens but I would love to hear from a optical designer about it.

Speaking of optical designers, I'm hoping that once we submit our spec that this chinese company will be able to provide some insight into problem solving/overcoming some of these issues. They seem to be a pretty sophisticated outfit. They may even be able to solve the orientation issue . . .

The orientation issue isn't a problem. Each lense inverts. It's just expensive. You could have an arrangement that is

35mm lense--GG----parrallelogram prism (or mirrrors arranged in the same way---Anachromatic lens----Parrallelogram prism--- camera.

I've been expermienting with this type of arrangment with mirrors on a tabletop. It works alright. It just needs someone who can make it to a high degree of competence! The camera focuses on the reflection of the GG in the last mirror in the chain.

Another thought
 

Related to the whole idea of these devices, is there a way of doing remote focus with modern DV cameras? I use Glidecam a lot and so the focus critical nature of such lenses would make it essential for such use.

What I meant to say was a remote focus that operates by way of a roller that adjusts the 35mm lens as opposed to the camera itself which wouldn't make any difference other than to defocus the entire picture!

Simon, I have seen one for Arri cams, so naturally it cost Thousands of dollars just cuz its Arri made.

Essentially it was a large gear affixed to the lens with a stepper motor fixed on the rods. It could be made, but not easily.

I think it was called a 'follow focus'

like this but with a motor.

http://cgi.ebay.com/ws/eBayISAPI.dll...&category=4691

Remote Focus:

http://www.unitcine.com/

cheaper than most of the bigger names I've seen. The main 'big' Hollywood remote focus systems are made by a company called Preston.

Hope this helps.

I'm still interested in what others have discovered is the most viable alternative to hand-ground glass??

This, IMO, is the biggest hurdle to leap at the moment. Rail systems can wait.

Anyone purchased materials or heard from Knight Optical? I've written them twice, but to no avail.

American companies haven't responded, either.

- jim

Well Jim, Its my take that the GG issue has been solved

Alain's homemade GG made from a UV filter would be optimal for these reasons:

Pro's
1. The glass is already optical quality
2. UV filters are cheap and readilly available
3. It only takes an hour to make
4. No glass cutting required
5. Filters are already threaded and ready for adaption

Con's
1. Aluminum Oxide grit is only available online unless you have a telescope shop around.

I just need to get off my ass and order some grit!

I found this place, it has SUB MICRON GRIT! cheap as hell too at a pound for $14.79 [AL-601]

http://www.micronmetals.com/aluminum_oxide.htm

35mm end
 

I personally have a Canon A-1 35mm lens...and I'm sure others have something different than an f-mount.

Would it be possible to front thread the thing with something that an adapter (either a 52mm thread to f-mount adapter, or a thread to canon fd adapter) could fit on?

Might save some of us from buying new camera lenses. (especially when we don't even own the cameras they go to)

Jeremiah

I only suggested a Nikon F mount since it seems to be the most prevelant in the 35mm industry. It's the only mount that hasn't changed in 50 years and because of this there is a large variety of both Nikon and third party lenses made for this mount over that period of time. You can buy an old used lens or a brand new one, a cheap lens or an expensive top of the line one and they all will work.

Sure there are a lot of people that have a lot of money invested in lenses for other camera systems. Consider though that their primary reason for buying those lenses were for the still camera they go to. A camera they still have and can still use with those lenses. This video adapter would constitute "a new camera" or "new camera system" thus buying lenses for it would be a given.

If the adapter just so happened to work with lenses you already owned then great. But it should be expected that as a new camera system new camera lenses may be required.

Just as a note though, I suggested the Nikon F mount for the reasons above and not because of any bias. I actually own more Minolta MD mount lenses then Nikkors. But looking at the broad scope of it the F mount would seem to be the practical choice for the reasons stated above. Versus trying to cater to everyone and their lens mount biases. Because trying to look at it from an engineering/production point of view the simpler the product the cheaper and easier to build. In other words it's easier for everyone to fit the product then it is for the product to try and fit everyone. Sure it may not be the most desired route, but in the end it would make it cheaper for us which is the whole motive behind all these discussions and projects.

If everyone decided to go with a Canon FD mount instead I wouldn't not buy the adapter. To me it would be the same as buying an XL1 knowing full well that my Nikkors or Minolta MD lenses wouldn't work with it. That I was buying into a new camera system and would need new lenses for it. But then again I look at the notion of this factory produced video adapter not as an extra toy or extension of my existing 35mm lenses but as a new tool in itself that may require it's own set of lenses and accessories. But if it does what it's meant to do it would be worth it and still only be a fraction of the cost of a min35.

Just as an addendum

I think we're all going to have enough on our plate trying to figure out how to mount our DV cameras to such a factory adapter. Keeping the front end of it as standarized as we can would be our best route. Different 35mm lens mounts have different flange to focal plane distances. Having to deal with lens mount adapters (possibly special made ones) on top of having to deal with the DV camera alignment would be even more troublesome. If we build the front end to a specific standard (such as the F mount, or a different mount) then at least we know that part of it will work no matter what when we attach a lens made for that mount. From there the only thing we have to troubleshoot is the DV camera fixture.