Homemade 35mm Adapter

Paul Bettner · November 24th, 2003, 02:13 AM

From the mini35 manual, it looks like the relay lens is something that goes between the DV camera lens and the ground glass, but in your set up it looks like the DV camera lens is just shooting the picture of the ground glass directly...

that's where I'm confused... it looks from your pictures like the DV camera lens is just sticking through the back of the box and taking a picture of the ground glass directly. Where is your "relay lens"? Is it a piece of glass that I can't see or is the relay lens just the lens of the DV camera itself?

Sorry about my confusion... maybe it's because the mini35 manual is for an XL1, which fits on the front of the camera directly instead of in front of a built-in lens like your camera?

Another question (Sorry, I should probably just wait for you to post more a more detailed website): How do you figure out the right distances between the back of the film lens, the ground glass, and the DV lens?

Finally: how did you fix the vignetting? I thought that required the use of some sort of fresnel piece?

paulb

p.s. it looks like eBay is a good place to find "real" ground glass. Just do a search for it and it turns up many results. With an 8x10 sheet of real ground glass and a circular glass cutter to make it the same size as a CD, maybe you can get a much better result (less light loss.)

Agus Casse · November 24th, 2003, 02:50 AM

Well, yeah you are right i am shooting directly to the ground glass, i use the term of "relay lens" just to undertand where it is positioned, sorry for that, my bad...

about the vigneting, you have to zoom in until it is gone, my cam has the manual focus broken (reason that i build the adapter!!) so to help the auto focus, i use a magnifying glass that i had from a wide conversion lens (the last glass magnify).

you can always get better ground glass if you buy it from a profesional, but my challenge was to build it with less than $10 (the cdrs box)... just to prove that the P+S adapter price is far overvalued, and you can get really good results with less, a lot less money.

I just shoot my self smooking a cigarette if you want to see, i can upload it in a couple of mins. (my baterries of the adapter are running low and it is 3am to go and buy another one, so you will notice that the ground glass speed isnt too fast) .

Paul Bettner · November 24th, 2003, 02:57 AM

Awesome... I will start experimenting soon! (Maybe tommorow?) Thank you for answering my questions!!

Is the magnifying glass required to make the set up work, or is that only in your case because of the broken manual focus? If it is required, where does it go in the setup?

I'd love to see more footage from the device. As much as you have! (I can host files for you also if you need bandwidth/web space - just let me know - paulbweb@hotmail.com)

paulb

Agus Casse · November 24th, 2003, 03:01 AM

Nah, it is not necesary to have the magnifying glass, i had the problem that when i zoomed it it went out of focus, thats why i used it... from there you should have no trouble at all.

Tomorrow we will shoot a TV spot with the adapter, lets see how it handle.... what i know for sure, is that i will need a lot more lighting equipment cause the ground glass loose a lot of light in the process.

Agus Casse · November 24th, 2003, 03:43 AM

http://altoque.tv/35mmAdapter/spotAdapter35mm.wmv

Some sample... hey.. i was bored... :)

Paul Bettner · November 24th, 2003, 03:55 AM

Oh man... I'm sure you feel the same way: that footage, even as simple as it is, looks just phenomenal coming from a TRV18... incredibly film-like, as they say. What else are you doing to that footage besides the adapter? It looks de-interlaced to me - does it have any other filmlook effects?

I'm very interested to see how this adapter handles in daylight.

Please keep us updated on how the shoot goes tommorow, as well as posting any more footage you have! I can't wait to get started building my own...

thank you so much,
paulb

Agus Casse · November 24th, 2003, 04:05 AM

I only use color corrector in premiere pro, in the daylight the adapter works perfectly, cause you have also the option to control the iris from the lens, that means less grain, i can underexpure and still get high light coming from the lens... it is a pretty tricky thing at first, but then you can have great control and excellent picture.

Cosmin Rotaru · November 24th, 2003, 04:11 AM

Hi Agus.
From the pics and your explanation I figured I could help you get better results...
"the ground glass loose a lot of light in the process"
A very fine GG will take away the vigneting but will also loose allot of light. A coarser GG will let more light to pass thorough, but you'll also gett allot of vignetting. You can get both a vignetting free image and also enogh light from the GG by combining a coarser (spinning, of course) GG and a fresnell lens. The fresnell lens, put in front of the GG (as close as posible) will even the light on the surface of the GG. (in front of hte GG - that is between the GG and the 35mm lens). Another thing to remember is that the fresnell lens, like any other lens, has its own focal point. The lens of the camcorder should be in that focal point of the fresnell, oherwise you'll not get rid of all vigneting. Now, depending of that focal distance, you'll need a "relay lens" so you can zoom in and focalize the camcorder on the GG.

Otherwise, with plenty of light, your footage looks great!

I hope you understand my bad english...

PS: You smoke to much! :)

Peter Sciretta · November 24th, 2003, 09:07 AM

I'm willing to pay someone to make me a working adapter...

Agus?

anyone?

Jean-Philippe Archibald · November 24th, 2003, 09:09 AM

Hi Angus!. It is very entertaining to follow your experimentation with you. But, maybe I am a stupid person (!!!) but I can't find a way to play your samples. Can you tell me which codec I need yo istall? or any other tips please?

Thanks a lot, and your adaptor look awesome!

P.S.: Which "film lens" are you using?

Nicholi Brossia · November 24th, 2003, 11:49 AM

Jean-Philippe,
I kept getting an error message as well (unknown error # C00D11CD) and became very frustrated because of how interesting this is. Finally, I downloaded the clip to my harddrive (right click - save target as) and it worked perfectly. Hopefully that's what you're running into.

Agus,
Great job on the mini35 project. I can guarantee that I will be visiting your website. I'd like to suggest something too... maybe you could set up a donation link (through paypal?) so people, like myself, can send you a small "thank you for all your work" donation after using your free plans. You definately disserve full credit for this discovery and it would be nice to recieve something in return.

Agus Casse · November 24th, 2003, 01:05 PM

Donation for what ?... come on guys, i learned a lot in this forum, it is time to give something back, also if this forum wouldnt exist, i would never knew how to build it.

Hey peter... come on, dont be lazy, it is a very fun project to do, once you get the projection coming in the ground glass, you just need to put all together....

Wish me luck, today i will shoot a tv spot.. hope the adapter really works in the real world.

Agus Casse · November 24th, 2003, 01:20 PM

<<<-- Originally posted by Jean-Philippe Archibald :

P.S.: Which "film lens" are you using? -->>>

I am an Minolta 50mm 1:2 lens from a SLR minolta camera, but i saw some 35mm lens from nikkon, with zoom, and focus control in like aprox $450 (reason that i willl shoot the video today, perhaps i could buy it if they take the ad)

Paul Bettner · November 24th, 2003, 05:13 PM

Agus, how did you figure out how far to place the 35mm lens from the CD and the CD from the lens of the DV camera?

paulb

Peter Sciretta · November 24th, 2003, 07:09 PM

I am horrible at building anything, couldn't even put together a dolly right, with help...

so the offer is out there... if anyone can build one of these please email me an offer, cause I am looking to buy such an adapter

Thanks

Peter

November 24th, 2003, 04:11 AM	#38
Cosmin Rotaru Major Player Join Date: Feb 2003 Location: Romania, Timisoara Posts: 453	Hi Agus. From the pics and your explanation I figured I could help you get better results... "the ground glass loose a lot of light in the process" A very fine GG will take away the vigneting but will also loose allot of light. A coarser GG will let more light to pass thorough, but you'll also gett allot of vignetting. You can get both a vignetting free image and also enogh light from the GG by combining a coarser (spinning, of course) GG and a fresnell lens. The fresnell lens, put in front of the GG (as close as posible) will even the light on the surface of the GG. (in front of hte GG - that is between the GG and the 35mm lens). Another thing to remember is that the fresnell lens, like any other lens, has its own focal point. The lens of the camcorder should be in that focal point of the fresnell, oherwise you'll not get rid of all vigneting. Now, depending of that focal distance, you'll need a "relay lens" so you can zoom in and focalize the camcorder on the GG. Otherwise, with plenty of light, your footage looks great! I hope you understand my bad english... PS: You smoke to much! :) __________________ Cosmin Rotaru

November 24th, 2003, 09:09 AM	#40
Jean-Philippe Archibald Trustee Join Date: Sep 2003 Location: Saguenay, Québec, Canada Posts: 1,051	Hi Angus!. It is very entertaining to follow your experimentation with you. But, maybe I am a stupid person (!!!) but I can't find a way to play your samples. Can you tell me which codec I need yo istall? or any other tips please? Thanks a lot, and your adaptor look awesome! P.S.: Which "film lens" are you using? __________________ Jean-Philippe Archibald http://www.jparchibald.com - http://www.vimeo.com/jparchib

November 24th, 2003, 11:49 AM	#41
Nicholi Brossia Major Player Join Date: Jun 2003 Location: Oklahoma City, OK Posts: 389	Jean-Philippe, I kept getting an error message as well (unknown error # C00D11CD) and became very frustrated because of how interesting this is. Finally, I downloaded the clip to my harddrive (right click - save target as) and it worked perfectly. Hopefully that's what you're running into. Agus, Great job on the mini35 project. I can guarantee that I will be visiting your website. I'd like to suggest something too... maybe you could set up a donation link (through paypal?) so people, like myself, can send you a small "thank you for all your work" donation after using your free plans. You definately disserve full credit for this discovery and it would be nice to recieve something in return. __________________ Nicholi Brossia

November 24th, 2003, 02:13 AM	#31
Paul Bettner Regular Crew Join Date: May 2003 Location: Dallas, TX Posts: 42	From the mini35 manual, it looks like the relay lens is something that goes between the DV camera lens and the ground glass, but in your set up it looks like the DV camera lens is just shooting the picture of the ground glass directly... that's where I'm confused... it looks from your pictures like the DV camera lens is just sticking through the back of the box and taking a picture of the ground glass directly. Where is your "relay lens"? Is it a piece of glass that I can't see or is the relay lens just the lens of the DV camera itself? Sorry about my confusion... maybe it's because the mini35 manual is for an XL1, which fits on the front of the camera directly instead of in front of a built-in lens like your camera? Another question (Sorry, I should probably just wait for you to post more a more detailed website): How do you figure out the right distances between the back of the film lens, the ground glass, and the DV lens? Finally: how did you fix the vignetting? I thought that required the use of some sort of fresnel piece? paulb p.s. it looks like eBay is a good place to find "real" ground glass. Just do a search for it and it turns up many results. With an 8x10 sheet of real ground glass and a circular glass cutter to make it the same size as a CD, maybe you can get a much better result (less light loss.)

November 24th, 2003, 02:50 AM	#32
Agus Casse Major Player Join Date: Jul 2003 Location: Guatemala Posts: 322	Well, yeah you are right i am shooting directly to the ground glass, i use the term of "relay lens" just to undertand where it is positioned, sorry for that, my bad... about the vigneting, you have to zoom in until it is gone, my cam has the manual focus broken (reason that i build the adapter!!) so to help the auto focus, i use a magnifying glass that i had from a wide conversion lens (the last glass magnify). you can always get better ground glass if you buy it from a profesional, but my challenge was to build it with less than $10 (the cdrs box)... just to prove that the P+S adapter price is far overvalued, and you can get really good results with less, a lot less money. I just shoot my self smooking a cigarette if you want to see, i can upload it in a couple of mins. (my baterries of the adapter are running low and it is 3am to go and buy another one, so you will notice that the ground glass speed isnt too fast) .

November 24th, 2003, 02:57 AM	#33
Paul Bettner Regular Crew Join Date: May 2003 Location: Dallas, TX Posts: 42	Awesome... I will start experimenting soon! (Maybe tommorow?) Thank you for answering my questions!! Is the magnifying glass required to make the set up work, or is that only in your case because of the broken manual focus? If it is required, where does it go in the setup? I'd love to see more footage from the device. As much as you have! (I can host files for you also if you need bandwidth/web space - just let me know - paulbweb@hotmail.com) paulb

November 24th, 2003, 03:01 AM	#34
Agus Casse Major Player Join Date: Jul 2003 Location: Guatemala Posts: 322	Nah, it is not necesary to have the magnifying glass, i had the problem that when i zoomed it it went out of focus, thats why i used it... from there you should have no trouble at all. Tomorrow we will shoot a TV spot with the adapter, lets see how it handle.... what i know for sure, is that i will need a lot more lighting equipment cause the ground glass loose a lot of light in the process.

November 24th, 2003, 03:43 AM	#35
Agus Casse Major Player Join Date: Jul 2003 Location: Guatemala Posts: 322	http://altoque.tv/35mmAdapter/spotAdapter35mm.wmv Some sample... hey.. i was bored... :)

November 24th, 2003, 03:55 AM	#36
Paul Bettner Regular Crew Join Date: May 2003 Location: Dallas, TX Posts: 42	Oh man... I'm sure you feel the same way: that footage, even as simple as it is, looks just phenomenal coming from a TRV18... incredibly film-like, as they say. What else are you doing to that footage besides the adapter? It looks de-interlaced to me - does it have any other filmlook effects? I'm very interested to see how this adapter handles in daylight. Please keep us updated on how the shoot goes tommorow, as well as posting any more footage you have! I can't wait to get started building my own... thank you so much, paulb

November 24th, 2003, 04:05 AM	#37
Agus Casse Major Player Join Date: Jul 2003 Location: Guatemala Posts: 322	I only use color corrector in premiere pro, in the daylight the adapter works perfectly, cause you have also the option to control the iris from the lens, that means less grain, i can underexpure and still get high light coming from the lens... it is a pretty tricky thing at first, but then you can have great control and excellent picture.

November 24th, 2003, 09:07 AM	#39
Peter Sciretta Regular Crew Join Date: Nov 2003 Posts: 72	I'm willing to pay someone to make me a working adapter... Agus? anyone?

November 24th, 2003, 01:05 PM	#42
Agus Casse Major Player Join Date: Jul 2003 Location: Guatemala Posts: 322	Donation for what ?... come on guys, i learned a lot in this forum, it is time to give something back, also if this forum wouldnt exist, i would never knew how to build it. Hey peter... come on, dont be lazy, it is a very fun project to do, once you get the projection coming in the ground glass, you just need to put all together.... Wish me luck, today i will shoot a tv spot.. hope the adapter really works in the real world.

November 24th, 2003, 01:20 PM	#43
Agus Casse Major Player Join Date: Jul 2003 Location: Guatemala Posts: 322	<<<-- Originally posted by Jean-Philippe Archibald : P.S.: Which "film lens" are you using? -->>> I am an Minolta 50mm 1:2 lens from a SLR minolta camera, but i saw some 35mm lens from nikkon, with zoom, and focus control in like aprox $450 (reason that i willl shoot the video today, perhaps i could buy it if they take the ad)

November 24th, 2003, 05:13 PM	#44
Paul Bettner Regular Crew Join Date: May 2003 Location: Dallas, TX Posts: 42	Agus, how did you figure out how far to place the 35mm lens from the CD and the CD from the lens of the DV camera? paulb

November 24th, 2003, 07:09 PM	#45
Peter Sciretta Regular Crew Join Date: Nov 2003 Posts: 72	I am horrible at building anything, couldn't even put together a dolly right, with help... so the offer is out there... if anyone can build one of these please email me an offer, cause I am looking to buy such an adapter Thanks Peter