35mm Adapter Static Aldu35

[Brett Erskine]

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/Disp...productid=1784

http://www.bhphotovideo.com/bnh/cont...&is=REG&BI=155

http://cgi.ebay.com/ws/eBayISAPI.dll...category=30030

http://cgi.ebay.com/ws/eBayISAPI.dll...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.

[Aykut Ozen]

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

[Jeremiah Rickert]

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

[Jim Lafferty]

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

[Brett Erskine]

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.

[Alain Dumais]

The adapter Made in China ???

Here is my final adapter.

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

Alain Dumais

[Jim Lafferty]

Alain --

Man, that sucker's huge.

- jim

[Todd Birmingham]

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?

[Aykut Ozen]

Alain,

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

Thanks

[Simon Wyndham]

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!

[Brett Erskine]

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

[Taylor Moore]

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

[Richard Mellor]

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

[Brett Erskine]

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.

[Taylor Moore]

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.