35mm Adapter Static Aldu35

Mike Tesh · February 10th, 2004, 02:53 AM

Course you could always just take any old LCD screen and mount it upside down. If it has a 1/4 inch screw threading on it somewhere this shouldn't be a problem.

A lot of these LCD's that offer flip and reverse options are for mounting upside down when the original video comes in correctly (i.e from a DVD player). We're dealing with video that doesn't come in correctly. So any LCD mounted upside down will work for us.

Brett Erskine · February 10th, 2004, 03:47 AM

Nope. I wish. This mistake has been made countless times on these threads before and I'll mention it again. You need to ALSO correct the image Left to Right. RMPP.

Alain Dumais · February 10th, 2004, 09:27 AM

If you rotate a lcd monitor to put it upside down it is flip left to right also. That's what I did.

Alain

Paul Doss · February 10th, 2004, 10:35 AM

If you rotate a lcd monitor to put it upside down it is flip left to right also. That's what I did.

That is absolutely right! It seems too simple but it works. If it is rotated 180 degrees it will be fine. Think rotating not flipping.

Paul

dvdof.com

Brett Erskine · February 10th, 2004, 02:10 PM

Wow I cant believe I looked over something so simple. Your right. I guess I missed that idea because I was working on another problem and thinking in terms of the simple limitations of prisms/mirrors. Great! Thanks.

Alain Dumais · February 11th, 2004, 11:18 PM

What's up here ?

Does any body as built something ,any improvement?

Brett , have you already find a good lcd monitor that you have try?

Alain

John Gaspain · February 12th, 2004, 01:45 AM

I just got my 1000 grit Alum Oxide in today from the rockshed, so I should have a working prototype soon. BTW therockshed.com ships FAST and they are cheap, my total w/ S/H was $8.35 for a pound!

Brett Erskine · February 12th, 2004, 02:14 AM

Nope. Still looking for that small LCD with vertical and horizontal picture squeeze/expand controls. Would love anybodys or everybodys help in find it. Check out the thread on LCD's for this project for more info.

Damn were close huh guys.

-Brett

Richard Mellor · February 12th, 2004, 04:59 AM

my 1000 grit aluminum oxide came in yesterday. from the rock shed http://www.therockshed.com/grit.html it was the same price 8.35 a pound shipped. i will be getting a lens in a few days.
alain will a uv lens be ok . i think i remember you used a skylight lens

Alain Dumais · February 12th, 2004, 10:00 AM

Yes Uv. but be shure to use a glass one ,not plastic.
Tiffen are good and you can unmount it easealy ,it is screw.

Alain

Richard Mellor · February 16th, 2004, 08:15 PM

I found a site that seems to be a good place to buy a lcd http://www.azo-store.com/newlcd/index.php3?sesid=C;NO1CM3ZEO8DFLBBHPC you can make an order as small as twenty five dollars . I also had an idea if we were to extend the length of the strap to the lcd maybe we could just turn it around .

Jonathon Wilson · February 18th, 2004, 04:32 PM

Provided you didn't mind spending $50-$100 (or slightly more), and provided you could physically find a place to put one of these in the image path, and provided that you didn't mind the inevitable additional loss of light that one of these would create, a Dove Prism as seen here:

http://www.edmundoptics.com/IOD/DisplayProduct.cfm?Productid=2034

Would be very nice for both an image 'rotation' which has the effect of both the top-to-bottom and left-to-right inversions we've been hunting for. This would happen right in the light path, so no LCD-flipping-gymnastics would be required.

The expense is yet another piece of glass to shoot photons through.

(Sure am enjoying these threads, all)

-Jonathon Wilson
Film Composer, camera/photography hobbyist
Austin, TX
jonathon@aqua-web.com

Eric MacIver · February 18th, 2004, 06:40 PM

Perhaps I'm a bit confused, but the way I see that this system has to work is as follows:

----------------------------------

Camera -> Normal Lens -> Achromatic Diopter ->
Light-proof "Spacer" #1 -> Ground Glass ->
Light-proof "Spacer" #2 -> 35mm Lens Adapter ->
35mm Lens of Choice.

Camera: I am using an XL1s, which has the ability to change the lens and it mounts right next to the CCD.

Normal Lens: For the XL1s, this would be the 16x AF lens that ships with the camera. For other cameras, this would be the built-in or default lens.

Achromatic Diopter: Power needed will vary depending on what camera and/or lens combination you are using. This allows the normal lens (above) to be able to focus on the image being projected on the Ground Glass.

Light-proof Spacer #1: This is simply a tube cut to the correct length for your Achromatic Diopter to be able to focus on the Ground Glass (because they obviously cannot be stacked directly on eachother). This should also be long enough so that the projected image captured by the achromatic diopter and original lens, lets the CCD see the full frame.

Ground Glass: Glass or other material that has been "frosted" on one side so that the light/image coming in from the front of the adapter is projected upon it. The smaller the grains that create the "frosting", the better, and if the grains are smaller than the size of the pixels the CCD picks up, they should be un-noticeable.

Light-proof "Spacer" #2: This is cut to the right length for the 35mm lens in front of the adapter to project its image at the correct size on the Ground Glass, which should be the size of a 35mm piece of film. The length of this spacer can be determined by viewing the chart located at: http://www.gregssandbox.com/gtech/filmfacts/flange.htm

35mm Lens Adapter: A mechanical adapter mounted to the spacer, allowing the use of interchangeable 35mm lenses.

35mm Lens of Choice: self explanatory.

----------------------------------

1) Can anyone correct me if I am wrong on any of this, or missing anything?

2) For the XL1s, can anyone suggest how we might cut out the need to mount this all to the end of the Normal Lens?

3) If the above was possible, wouldn't we NOT need to worry about flipping/rotating the image?

I ask because I have a business contact that can make small runs of precicely designed metal, and he is local, in the US. If we could come up with a set of specifications for the metal adapters, I can have him create them at a relatively low cost.

If we were able to get the metal parts made at a good price, we might also have the ability to get a pre-produced GG supplement. I also know someone that MIGHT be able to manufacture that as well.

Just thinking we might be able to get this whole thing produced in a professional-strength package, with rails and more for under $1k per unit (perhaps even considerably less, depending on materials and features). Any thoughts or help?

Jonathon Wilson · February 18th, 2004, 06:55 PM

One area that deserves more attention before embarking on mass-production efforts would be that mentioned by Brett - the use of a condensor or aspherical lens prior to the ground glass. In virtually all of the test images and film posted, there has been a certain amount (sometimes negligable) of fuzziness and/or darkening in the corners caused by spherical distortion. This is specifically what aspherical lenses are for. (Aspherical or condensor or I've heard them called 'split' fresnels, which is wrong are a lens which is concave on one side and flat on the other. Imagine a standard magnifying glass, but split in half.. and you just take one half). In most of the diagrams I've seen, the aspherical lens is pressed right up against the surface of the ground glass, such that you could even 'grind' the flat side of the condensor for the same effect.

Many times, a second aspherical sits pressed against the other side of the image plane in the other direction. I believe this is basically the function our diopters/macros are performing, and as we're trying to focus through the existing camcorder lens already, I don't think there's any way to include this second reversed condensor. The advantage to including it right on the far side of the ground glass is fewer lens-to-air connections. Each one of these (and we already have a lot) introduces a decrease in contrast, and potential increase in halos and flares. It would be nice to decrease these wherever possible.

The aspherical basically removes spherical distortion (corners should be as clear as the center), while amplifying the existing light level (which we could all benefit from in a system like this).

I'm hoping to press a condenser smack up against my ground glass in my current design attempt (first attempt, so I'm sure there will be many other bugs I have to work out that y'all have already solved) and see if I can remove spherical artifacts while increasing light. We'll see how it works.

I'm no expert, but do some reading on asphericals - they may be the next area of possible improvement for an already sweet DIY adapter.

Mike Tesh · February 18th, 2004, 07:37 PM

Jonathon Wilson
Do you know where to get a condenser lens? I've been having trouble finding one on the net.

Also I like the idea of just grinding down the flat side of the condenser to work as the ground glass element. It seems like it would save trying to mount two different elements together. But would there be a downside to this?

February 10th, 2004, 02:53 AM	#181
Mike Tesh Major Player Join Date: Jan 2003 Location: Detroit MI Posts: 253	Course you could always just take any old LCD screen and mount it upside down. If it has a 1/4 inch screw threading on it somewhere this shouldn't be a problem. A lot of these LCD's that offer flip and reverse options are for mounting upside down when the original video comes in correctly (i.e from a DVD player). We're dealing with video that doesn't come in correctly. So any LCD mounted upside down will work for us. __________________ ScapeFilms.com \| My Photography \| IMDB Profile

February 10th, 2004, 09:27 AM	#183
Alain Dumais Regular Crew Join Date: Jan 2004 Location: Montreal Canada Posts: 86	Brett If you rotate a lcd monitor to put it upside down it is flip left to right also. That's what I did. Alain __________________ http://www.kheops-tech.com/~ad3d/

February 11th, 2004, 11:18 PM	#186
Alain Dumais Regular Crew Join Date: Jan 2004 Location: Montreal Canada Posts: 86	What's up here ? Does any body as built something ,any improvement? Brett , have you already find a good lcd monitor that you have try? Alain __________________ http://www.kheops-tech.com/~ad3d/

February 12th, 2004, 01:45 AM	#187
John Gaspain Major Player Join Date: Oct 2003 Location: WA-USA Posts: 371	I just got my 1000 grit Alum Oxide in today from the rockshed, so I should have a working prototype soon. BTW therockshed.com ships FAST and they are cheap, my total w/ S/H was $8.35 for a pound! __________________ The glory of the World passes by.

February 12th, 2004, 04:59 AM	#189
Richard Mellor Major Player Join Date: Nov 2003 Location: cambridge ma Posts: 247	aluminum oxide my 1000 grit aluminum oxide came in yesterday. from the rock shed http://www.therockshed.com/grit.html it was the same price 8.35 a pound shipped. i will be getting a lens in a few days. alain will a uv lens be ok . i think i remember you used a skylight lens

February 10th, 2004, 03:47 AM	#182
Brett Erskine Major Player Join Date: Dec 2003 Location: Anaheim, CA Posts: 445	Nope. I wish. This mistake has been made countless times on these threads before and I'll mention it again. You need to ALSO correct the image Left to Right. RMPP.

February 10th, 2004, 10:35 AM	#184
Paul Doss Regular Crew Join Date: Feb 2002 Location: Gulf Shores, Alabama Posts: 57	If you rotate a lcd monitor to put it upside down it is flip left to right also. That's what I did. That is absolutely right! It seems too simple but it works. If it is rotated 180 degrees it will be fine. Think rotating not flipping. Paul dvdof.com

February 10th, 2004, 02:10 PM	#185
Brett Erskine Major Player Join Date: Dec 2003 Location: Anaheim, CA Posts: 445	Wow I cant believe I looked over something so simple. Your right. I guess I missed that idea because I was working on another problem and thinking in terms of the simple limitations of prisms/mirrors. Great! Thanks.

February 12th, 2004, 02:14 AM	#188
Brett Erskine Major Player Join Date: Dec 2003 Location: Anaheim, CA Posts: 445	Nope. Still looking for that small LCD with vertical and horizontal picture squeeze/expand controls. Would love anybodys or everybodys help in find it. Check out the thread on LCD's for this project for more info. Damn were close huh guys. -Brett

February 12th, 2004, 10:00 AM	#190
Alain Dumais Regular Crew Join Date: Jan 2004 Location: Montreal Canada Posts: 86	Richard Yes Uv. but be shure to use a glass one ,not plastic. Tiffen are good and you can unmount it easealy ,it is screw. Alain __________________ http://www.kheops-tech.com/~ad3d/

February 16th, 2004, 08:15 PM	#191
Richard Mellor Major Player Join Date: Nov 2003 Location: cambridge ma Posts: 247	lcd I found a site that seems to be a good place to buy a lcd http://www.azo-store.com/newlcd/index.php3?sesid=C;NO1CM3ZEO8DFLBBHPC you can make an order as small as twenty five dollars . I also had an idea if we were to extend the length of the strap to the lcd maybe we could just turn it around .

February 18th, 2004, 04:32 PM	#192
Jonathon Wilson Regular Crew Join Date: Feb 2004 Location: Austin, TX Posts: 182	Dove Prisms for Image Rotation Provided you didn't mind spending $50-$100 (or slightly more), and provided you could physically find a place to put one of these in the image path, and provided that you didn't mind the inevitable additional loss of light that one of these would create, a Dove Prism as seen here: http://www.edmundoptics.com/IOD/DisplayProduct.cfm?Productid=2034 Would be very nice for both an image 'rotation' which has the effect of both the top-to-bottom and left-to-right inversions we've been hunting for. This would happen right in the light path, so no LCD-flipping-gymnastics would be required. The expense is yet another piece of glass to shoot photons through. (Sure am enjoying these threads, all) -Jonathon Wilson Film Composer, camera/photography hobbyist Austin, TX jonathon@aqua-web.com

February 18th, 2004, 06:40 PM	#193
Eric MacIver Regular Crew Join Date: Sep 2003 Location: Los Angeles, CA Posts: 121	Mounting a diopter...? Perhaps I'm a bit confused, but the way I see that this system has to work is as follows: ---------------------------------- Camera -> Normal Lens -> Achromatic Diopter -> Light-proof "Spacer" #1 -> Ground Glass -> Light-proof "Spacer" #2 -> 35mm Lens Adapter -> 35mm Lens of Choice. Camera: I am using an XL1s, which has the ability to change the lens and it mounts right next to the CCD. Normal Lens: For the XL1s, this would be the 16x AF lens that ships with the camera. For other cameras, this would be the built-in or default lens. Achromatic Diopter: Power needed will vary depending on what camera and/or lens combination you are using. This allows the normal lens (above) to be able to focus on the image being projected on the Ground Glass. Light-proof Spacer #1: This is simply a tube cut to the correct length for your Achromatic Diopter to be able to focus on the Ground Glass (because they obviously cannot be stacked directly on eachother). This should also be long enough so that the projected image captured by the achromatic diopter and original lens, lets the CCD see the full frame. Ground Glass: Glass or other material that has been "frosted" on one side so that the light/image coming in from the front of the adapter is projected upon it. The smaller the grains that create the "frosting", the better, and if the grains are smaller than the size of the pixels the CCD picks up, they should be un-noticeable. Light-proof "Spacer" #2: This is cut to the right length for the 35mm lens in front of the adapter to project its image at the correct size on the Ground Glass, which should be the size of a 35mm piece of film. The length of this spacer can be determined by viewing the chart located at: http://www.gregssandbox.com/gtech/filmfacts/flange.htm 35mm Lens Adapter: A mechanical adapter mounted to the spacer, allowing the use of interchangeable 35mm lenses. 35mm Lens of Choice: self explanatory. ---------------------------------- 1) Can anyone correct me if I am wrong on any of this, or missing anything? 2) For the XL1s, can anyone suggest how we might cut out the need to mount this all to the end of the Normal Lens? 3) If the above was possible, wouldn't we NOT need to worry about flipping/rotating the image? I ask because I have a business contact that can make small runs of precicely designed metal, and he is local, in the US. If we could come up with a set of specifications for the metal adapters, I can have him create them at a relatively low cost. If we were able to get the metal parts made at a good price, we might also have the ability to get a pre-produced GG supplement. I also know someone that MIGHT be able to manufacture that as well. Just thinking we might be able to get this whole thing produced in a professional-strength package, with rails and more for under $1k per unit (perhaps even considerably less, depending on materials and features). Any thoughts or help?

February 18th, 2004, 06:55 PM	#194
Jonathon Wilson Regular Crew Join Date: Feb 2004 Location: Austin, TX Posts: 182	Ignoring of ASpherical Lens One area that deserves more attention before embarking on mass-production efforts would be that mentioned by Brett - the use of a condensor or aspherical lens prior to the ground glass. In virtually all of the test images and film posted, there has been a certain amount (sometimes negligable) of fuzziness and/or darkening in the corners caused by spherical distortion. This is specifically what aspherical lenses are for. (Aspherical or condensor or I've heard them called 'split' fresnels, which is wrong are a lens which is concave on one side and flat on the other. Imagine a standard magnifying glass, but split in half.. and you just take one half). In most of the diagrams I've seen, the aspherical lens is pressed right up against the surface of the ground glass, such that you could even 'grind' the flat side of the condensor for the same effect. Many times, a second aspherical sits pressed against the other side of the image plane in the other direction. I believe this is basically the function our diopters/macros are performing, and as we're trying to focus through the existing camcorder lens already, I don't think there's any way to include this second reversed condensor. The advantage to including it right on the far side of the ground glass is fewer lens-to-air connections. Each one of these (and we already have a lot) introduces a decrease in contrast, and potential increase in halos and flares. It would be nice to decrease these wherever possible. The aspherical basically removes spherical distortion (corners should be as clear as the center), while amplifying the existing light level (which we could all benefit from in a system like this). I'm hoping to press a condenser smack up against my ground glass in my current design attempt (first attempt, so I'm sure there will be many other bugs I have to work out that y'all have already solved) and see if I can remove spherical artifacts while increasing light. We'll see how it works. I'm no expert, but do some reading on asphericals - they may be the next area of possible improvement for an already sweet DIY adapter. __________________ http://www.aqua-web.com

February 18th, 2004, 07:37 PM	#195
Mike Tesh Major Player Join Date: Jan 2003 Location: Detroit MI Posts: 253	Jonathon Wilson Do you know where to get a condenser lens? I've been having trouble finding one on the net. Also I like the idea of just grinding down the flat side of the condenser to work as the ground glass element. It seems like it would save trying to mount two different elements together. But would there be a downside to this? __________________ ScapeFilms.com \| My Photography \| IMDB Profile