plastic focusing screens

Dave Parker · Sep 17, 2005

Sandy,

Send me your address, and a format, I will be happy to send you a screen to evaluate, the only thing I ask, is evaluate it fairly.

Dave

Peter De Smidt · Sep 17, 2005

Linhof used to make a plastic screen with a built in fresnel called the Super Screen, and they sold a glass plate to protect it. I had a Super Screen for awhile on a 4x5. Viewing was very good, but the screen did flex a little more than a regular ground glass. (I didn't have the glass protective plate. It had lots of format lines on it which I didn't like.) I worried that placing a loupe on it might actually change focus, at least in the middle. {Is viewing screen flex a problem with 8x10 and bigger cameras?}

Didn't Minolta sell Accumatte screens to other manufactures for awhile? Their screens had very good reputations. On my 4x5 I have a Maxwell screen which I'm very happy with. In 8x10 I'm happy with a regular Sinar ground glass. If that every breaks I'll get a Satin Snow.

sanking · Sep 18, 2005

Satinsnow said:
Sandy,

Send me your address, and a format, I will be happy to send you a screen to evaluate, the only thing I ask, is evaluate it fairly.

Dave

Dave,

I will send you a PM with the address and fit information. It will be a pleasure to evaluate a satinsnow screen, though from the numerous other comments I have no doubt but that it is a quality product.

Sandy

Jim Chinn · Sep 18, 2005

Satinsnow said:
Sandy,

It was not a critizim at all, that is not what I meant, and I am glad you found a screen that you like, actually I have several thousands square inches of various plastics around my shop that can, and do work very good for screens, they are very expensive, quite a bit more than the average user will pay, which is why I went to work developing the process I did, but again, not saying anything bad at all about plastics, its good stuff, just a bit expensive and most plastics will shift color(albeit slight in certain materials) in a couple of years, we are always doing R&D to see if there is something better, but again, not saying anything bad..

Dave

Thre is plastics out there that can accomodate everything you ask for. I did extensive research and will look for my notes for the exact product name. I remember I found the trade name in an article about ballistic glass. This particular plastic machines and mills almost like steel and polishes to a perfect clarity. It is also used in scientific applications where a chemical is mixed with it (it might have been a thin seperate element in the plastic) and when an electrical charge is applied the glass can go completely dark. Dave may know the name from these references. I recall that it was produced in 1" thick sheets and cost about $40 a square inch. I think I figured at the time that after machining and polishing you could have an industructible GG or 8x10 electro-chmical shutter for about $4200.

Like Lee pointed out, the real problem is protecting the GG when the camera is not in use during storage and transprotation.

Dave Parker · Sep 18, 2005

Jim,

There are a couple of different types of plastics that reacte the way your describing, one is electrical charged and there is a version that is alway light reactive when the spectrum goes above a certain level, these the light reactive ones are very common in the welding field, the electrical charged plastics are used in aviation quite a bit and have adjustments for certain levels of dark..very high tech and very expensive stuff, I have a couple of 6 in pieces of each, the light reactive plastics are really comming down in price though.

Dave

sanking · Oct 18, 2005

Dave,

You offered to send me a screen to evaluate. I contacted you by private email shortly thereafter but have not received any recognition of my message. Did you receive my message?

Sandy

Satinsnow said:
Sandy,

Send me your address, and a format, I will be happy to send you a screen to evaluate, the only thing I ask, is evaluate it fairly.

Dave

Dave Parker · Oct 18, 2005

sanking said:
Dave,

You offered to send me a screen to evaluate. I contacted you by private email shortly thereafter but have not received any recognition of my message. Did you receive my message?

Sandy

Yes Sandy,

I received the message and I will ship one to you soon..Thanks I look forward to your review of our screens.

Dave

sanking · Oct 18, 2005

Satinsnow said:
Yes Sandy,

I received the message and I will ship one to you soon..Thanks I look forward to your review of our screens.

Dave

Hi Dave,

Thanks a bunch for your response. If the screen is as good as I am lead to believe by the favorable comments of other users I will probably wind up buying more than one.

Best,

Sandy

TracyStorer · Oct 18, 2005

Hey folks.
For many many years, I used a "fresnel one side, diffusion on the plain side" focusing screen on the Polaroid 20x24. When I came to CA and started working on the camera I have now, (Polaroid/Wisner/Storer 20x24) I could not find the appropriate Fresnel. (infinity conjugate on the wrong side) What I have been doing for the last 8 years is using a large fresnel layered with a piece of P-95 Clear Plex.
This is also my setup for 14"x17". "Practically unbreakable" is a huge draw for me, especially in the large sizes.
The P-95 is frosted on one side, but the diffusion is light, very uneven illumination unless used with a fresnel. For 5x7 and 8x10 I use the P-95 with cheap "page reader" fresnels for composing, then drop the fresnel back in the bag for fine focusing. A drawback of the P-95 is the texture is a bit coarse, so smaller format users may not be able to find good detail to focus.

Dave Parker · Oct 18, 2005

TracyStorer said:
Hey folks.
For many many years, I used a "fresnel one side, diffusion on the plain side" focusing screen on the Polaroid 20x24. When I came to CA and started working on the camera I have now, (Polaroid/Wisner/Storer 20x24) I could not find the appropriate Fresnel. (infinity conjugate on the wrong side) What I have been doing for the last 8 years is using a large fresnel layered with a piece of P-95 Clear Plex.
This is also my setup for 14"x17". "Practically unbreakable" is a huge draw for me, especially in the large sizes.
The P-95 is frosted on one side, but the diffusion is light, very uneven illumination unless used with a fresnel. For 5x7 and 8x10 I use the P-95 with cheap "page reader" fresnels for composing, then drop the fresnel back in the bag for fine focusing. A drawback of the P-95 is the texture is a bit coarse, so smaller format users may not be able to find good detail to focus.

And the purpose of your post was???

I am a bit confused as to what you are trying to say here Tracy..

Thanks

Dave Parker
Satin Snow Ground Glass

TracyStorer · Oct 18, 2005

Satinsnow said:
And the purpose of your post was???

I am a bit confused as to what you are trying to say here Tracy..

Thanks

Dave Parker
Satin Snow Ground Glass

WHAT I WAS SAYING IS "YOU CAN USE P-95 WITH A FRESNEL, IT WORKS WELL WITH SOME CAVEATS" FURTHER, "I USED TO USE SOMETHING JUST LIKE WHAT SANDY MENTIONED, BUT HAVE NOT BEEN ABLE TO REPLICATE IT EITHER"

Dave Parker · Oct 18, 2005

TracyStorer said:
WHAT I WAS SAYING IS "YOU CAN USE P-95 WITH A FRESNEL, IT WORKS WELL WITH SOME CAVEATS" FURTHER, "I USED TO USE SOMETHING JUST LIKE WHAT SANDY MENTIONED, BUT HAVE NOT BEEN ABLE TO REPLICATE IT EITHER"

And your reason for Yelling????

I was asking a legitimate question, I am always looking at the different things that go around in the screen industry..

So please, why would you yell, when someone was asking a legitimate question?

Now I am really confused!

Dave Parker
Satin Snow Ground Glass

TracyStorer · Oct 18, 2005

PMs exchanged. all is fine. I'll post more about my various focusing woes and experiences for everyone soon.
Tracy

laz · Oct 18, 2005

Must be a full moon tonight!

plastic focusing screens

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