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.

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?ViewItem&item=2983758246&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

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.

As far as still camera bodies are concerned as I remember there are third party lens adapters out there already for anyone who wants to fit say a Minolta on a Nikon or perhaps a Nikon on a Canon (etc..). Personally Im into this project not only for the DOF but I plan on using PL mount anamorphic lens so I can double my vertical resolution of my footage. So I'm going to have a PL mount on my adapter. Not to mention they have PL to Nikon mount adapter rings out there so you get the best of both worlds. More expensive for sure but the mini35 becomes twice as useful.

Anyways back to the first heardle - the achromat macro/diopter type lens. This has been real hard to find. There are equations at www.dvxuser.com on how to determine the power of the diopter thats going to work for you but nothing beats trial and error. I own a DVX. This is one of the hardest cameras to find a diopter for because of both its lens diameter and poor minimum focus distance (dvx100a model does a better job). I've determined I need at least a +16/5x power achromat to see the target area size of 24mm x 18mm. I have only seen this spec in optics for high end loupes, hand held aspheric magnifing lens and microscope lenses. Obviously the microscope lenses are too small to shoot through but perhaps these achromat loupes lor a large magnifing lenses like these might do the trick:

http://www.edmundoptics.com/IOD/DisplayProduct.cfm?productid=1784

http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=97287&is=REG&BI=155

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2983326078&category=30030

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2376274020&category=16508

http://www.eschenbach.com/catalog/subfamily.asp?18

Now these are all smaller in diameter then 72mm but, to a point, that shouldnt matter because we're most likely zooming in just a little anyways. Hope these help.

Todd,

I think an official prototype is a great idea...it would be great if they can keep it as simple as it is and compatible with 52-58-72mm(for dvx100) lens threads..or i guess using a step up ring would work for everyone...The point is keeping it simple and cheap...logically i think the best would be just to produce the macro,ground glass combination with the slr lens mount on single adapter so everyone can use their own choice of lenses...hopefully they won't exaggerate the price of this simple and great idea.

Thanks to everyone

Is there such a thing as a f-mount to Canon FD mount adapter?

I piddled around on ebay and found a few other adapters to and from canon FD's, but didn't notice a nikon to canon one.

Jeremiah

Since the general consensus is toward hand-grinding lenses, I've got a few questions fo those of you financially equipped to take the leap into purchasing aluminum-oxide and your other components:

What grade of aluminum-oxide is the minimum needed to successfully create a GG? #500?

As a subset of this question -- what grade is optimal?

I've taken note of the link to sub-micron aluminum-oxide (which is $23.20 a pound, BTW) but I'm wondering if this is, in fact, a superior solution. In other words -- would it be possible to create too fine a grain?

Is the goal to create gaps between grains that are just wide enough to allow light to pass through, but at the same time, create fine enough grains so as to never pick them up on the CCD? What's the balance between these two, if any?

Or is the desire just to create a uniform frost of a particular opacity, with grains merely small enough to not be seen -- and all else is fair game?

- jim

I can tell you that any light passing straight thru the glass without hitting the "frosted/grain" would be wasted as it wouldnt help produce the projected image. As far as the shape fine grain - past it needing to be smaller than what the camera's CCD can pick up - Im not sure what texture would work best. It would be fair to say some textures would scatter the light differently then others. For example some would add more of a unwanted diffused look to the image while others may be very effecient and diffuse the image only as much as it needs to to create a image on the groung glass. These effecient textures would most likely produce a image that can only best be viewable straight on because most of the light isnt being scattered too much and wasted. In the end its a interesting point that probably can only be answered by a optical designer.

The adapter Made in China ???

Here is my final adapter.

http://ideaspora.net/aldu35/ALDU35.JPG

Alain Dumais

Alain --

Man, that sucker's huge.

- jim

okay, if that's the final adapter, then we should have enough to move ahead with specifications to send to the manufacturing company. Does anyone have any specific instructions together?

Alain,

Can you post some clips with the new adapter if you have time...

Thanks

Off the subject a little, the look of Alains adaptor makes me wanna get some barn doors too for the complete pro look! :-)

Nice work Alain!

Hey Alain what EXACTLY are you using for your macro lens?

Hoya sells +10 two element achromat macro filters. They are the single strongest photo marketed screw on macro lens I've ever found and they are chroma aberration free.

They come in 55mm, 52mm, and 49mm sizes and sell for about $67 here:

http://www.2filter.com/hoya/hoyacloseup07.html

heres some info on them

http://www.camerastore.com/cat_003_hoya/003macro.html

Brett Erskine
Director of Photography
Premiere Visions
1761 W. La Palma Ave., Suite #302
Anaheim, CA 92801 www.CinematographerReels.com
BErskine@CinematographerReels.com

Brett,
Do you think one of the Hoya lens could be used with the DVX and a stepup ring?

alain it looks great. I am waiting for the order of aluminum oxide
I can't wait to start work on the aldu35 your hard work with the ground glass was the breakthrough .I remember the clip of the hand painted pottery. this device will help the small filmmaker
create a artistic look that was beyond our means. this is truly
a device for the people. thank you for all your hard work

As far as whether or not the above Hoya macro lens will work on the DVX with a step down ring - the short answer is you wont know for sure without trying it. I have a DVX and I plan on doing the following to get a better idea if it will work before I buy:

1)A quick referance could be made by grabing anything that measures just under 55mm such as a ruler or another type of filter and hold it in front of the DVX's lens. See if you can zoom thru the filter (or past the 55mm markings in the case of the ruler)

2)For the DVX you'll need a macro lens like the Hoya but more than one stacked on top of each other to make it a total of at least a +13 diopter rating. And if you plan on using 35mm MOTION PICTURE lenses you'll need it all to add up to a +16 or greater. The second macro lens doesnt have to be a +10. Hoya and alot of other companies make +3, +7, etc. But its absolutely necessary that they both are two element achromats.

3)Remember that between the step down ring(s) and the two somewhat thicker Hoya filters stacked on top of each other - it will add a bit more length to the system in front of the lens so you might have to zoom in just a bit more than if you simply had one lens on.

The simple fact that this will add about a $100 to the project is sure to deter some people but for thoughs looking at this adapter as a professional solution and are unwilling to sacrifice a noticeable amount of image sharpness for 35mm DOF the investment is well worth it.

I really appreciate your homework and truely would like to have the option of both SLR lens and Arri or PL lens options. Looking forward to your test results.

Bret (and others): I am working on one of these devices for my Canon GL2. My aluminum oxide is expected to arrive today and my uv filter is waiting.

As far as I understand from reading these posts, I want to take the projected image from the ground glass and have it fill the entire frame of the camera, by enlarging the projected image via a separate magnifier and/or zooming in on the image.


For the GL2 in particular, with a 58mm filter thread, what would you recommend in the way of a diopter/achromat/magnifier?


Currently, all I have for my GL2 is the WD58h Wide Angle lens, which I don't think would be of any use for this project.

Any help from you guys would be really appreciated!


,Frank

Each camera's stock lens has different characteristics so you may or may not need such a powerful diopter. Trial and error is going to be the best way for you any anyone else that wants to find out what power diopter they need for their particular camera.

The easiest way to do it will be to go down to your local camera shop that has thoughs cheap single element diopters (often in a three pack of +1, +3, +5) and start stacking them until you can fill the frame with a square measuring 24mm by 18mm. When you find the perfect combination add up all the filter powers and thats the power that you'll need to find in a achromat (two element)diopter.

Brett Erskine
Director of Photography
Premiere Visions
1761 W. La Palma Ave., Suite #302
Anaheim, CA 92801
www.CinematographerReels.com
BErskine@CinematographerReels.com

Heres another option for a macro lens. Its a double element thats aprox. +16.7 in power and the beauty is you only need one of these. The glass itself measures 40mm and woud need to be fitted into a aftermarket filter ring. You can find it here:

http://www.edmundoptics.com//IOD/DisplayProduct.cfm?productid=1749

Stock Number: NT45-218

Brett Erskine
Director of Photography
Premiere Visions
1761 W. La Palma Ave., Suite #302
Anaheim, CA 92801
www.CinematographerReels.com
BErskine@CinematographerReels.com

Alain how is the hot spot issue with this static solution?

How are people resolving this issue?

Alain good progress!
Couple questions for Brett and Alain.
Brett how is the Chinese idea going?
Alain what is that lcd maximizer you are using? Does it help out a lot?
Seems like your adapter is the what i am going for in a way.

Brett: Thanks! If that one is the only piece I would need, then I'd be willing to spend that for it.

I appreciate your research and input!


,Frank

Dmitri take another look at the past post. I don't have anything to do with that idea. It would be nice if it ends up working out though.

On a side note we have a hell of alot more people reading versus contributing to this thread. More of us need to get involved and less of us should be just waiting in the shadows while everyone else does all the work for them. Want this project finished faster/better? I cant under rate the importance of getting involved. To everyone else great job!

I am looking for an adapter that will let me clip in my 50mm lens to my device, any ideas?

Thanks

Alain's got new (and improved!) footage up:

http://ideaspora.net/aldu35/newclip.wmv

(right-click, save-as)

- jim

My order of 120 and 240 grit Al. Ox. has arrived. I have to wait 4 weeks for 600 grit. Has anyone found 500 or 600 grit that is not on back order? Thanks

Todd:
I got my 600 grit from here:
http://www.sisweb.com/ms/sis/alumoxid.htm

Cost me under $15 for a 4oz bottle + shipping. Ordered it last week (Thursday) and it is in now.

Very friendly people on the phone. I recommend them.

,Frank

Found another place for aluminum oxide.

http://www.rocks4u.com/

It's a rock polishing company. I called them and have all sorts different grits of aluminum oxide. He even mentioned some sort of diamon dust stuff that they have up to like 100,000

Anyways they seemed pretty cheap and shipping is only going to be a couple of days.

<<<-- Originally posted by Frank Ladner : Todd:
I got my 600 grit from here:
http://www.sisweb.com/ms/sis/alumoxid.htm

Cost me under $15 for a 4oz bottle + shipping. Ordered it last week (Thursday) and it is in now.

Very friendly people on the phone. I recommend them.


,Frank -->>>

whats up with the extra $10 'handling fee'?, makes the total $25 plus s/h = $30+ , I wouldnt pay that out of sheer principle.

Dont forget the issue with the hot spot. Hot spots on the ground glass are due to both your cameras viewing angle and the angle at which the 35mm image is being projected at. The greater its off axis from the camera the worse the light fall off on the edges. And dont just zoom in past it. That a cheap way around that will make alot of other things worse (DOF, grain, FOV, exposure, etc.).

How do you fix it properly?

Just look at a SLR viewfinder for the answers. Right before the light hits the ground glass in a still camera's viewfinder it goes through a small lens thats job is to redirect the image coming from the 35mm lens and send all angles straight at the ground glass. Thats why their arent any hot spots in you still camera viewfinder. It also makes the whole system more light effecient. Alot of people dont seem to be including this lens in their design and choosing to just zoom past it all. For everyone the lens I talking about is called a condensor and come in two types (fresnel and a regular lens). I highly recommend that you dont choose the fresnel type because the ridges of its design will project themselves on your ground glass and will be viewable to your video camera.

Brett Erskine
Director of Photography
Premiere Visions
1761 W. La Palma Ave., Suite #302
Anaheim, CA 92801
www.CinematographerReels.com
BErskine@CinematographerReels.com

John: Sorry, I forgot to mention. Since I called the order in, the guy said they wouldn't charge that handling fee. May sound wierd, but apparently they charge that for internet orders.

,Frank