View Full Version : Fresnel Ground glass
Who makes one piece fresnel ground glass? I know that Maxwell, Wista, Canham. Is there another manufacture? Which of those screens is the best?
The Maxwell (which I have) is actually three pieces: 1) GG; 2) fresnel; 3) protective cover glass.
I doubt you'll find a one-piece combination GG/fresnel since they require fundamentally different manufacturing processes.
- Leigh
I have a Canham screen and a Wista. Both one piece, requires protective glass.
timparkin
2-Jun-2012, 02:11
The Maxwell (which I have) is actually three pieces: 1) GG; 2) fresnel; 3) protective cover glass.
I doubt you'll find a one-piece combination GG/fresnel since they require fundamentally different manufacturing processes.
- Leigh
Hi Leigh,
My maxwell is a combined ground glass and fresnel (a moulding with the fresnel on one side and his brilliant ground glass surface on the other). The cover glass is from my original ebony. I didn't know he made different ones..
Tim
The Wista fresnel screen is very good a one piece combined screen & fresnel with a protective cover, there's also Beattie screens I have one on one of my 10x8 cameras, again very bright. I also have 3 cameras with glass screens and separate fresnels these aren't quite as bright as the Wista & Beattie but still very easy to use without a darkcloth (just the Grfalex hoods).
To a large extent it depends on how much you want to spend. In the UK the Beattie screen for my 10x8 is £350 ($535) to buy new and a 5x4 screen is not that much leee £315, US prices may are quite a bit cheaper. Luckily for me the seller just gave me a new boxed Beattie screen with my camera :D
Ian
I think Tachihara also makes a GG/fresnel that requires a glass overlay.
I had Canham, and had Wista, never had Maxwell, never compared them side by side. Has someone compared these side by side?
The Maxwell (which I have) is actually three pieces: 1) GG; 2) fresnel; 3) protective cover glass.
Not the Hi-Lux screen. It's one molded piece (with the focus surface--not actually ground--facing the lens and the Fresnel facing the user) and one sheet of clear cover glass.
Rick "who's never seen a Maxwell screen that used two parts for the focus surface and the Fresnel" Denney
Bob Salomon
4-Jun-2012, 09:29
Wista makes ground glasses:
211214 with grid pattern
211221 with 69 marked
Wista makes Fresnels:
211229 for most 45 lenses
211230 for long 45 lenses
Wista makes Protection glass:
211240 45 plain glass protection glass
211241 45 protection glass with grid lines
Wista does not make a ground glass with a Fresnel on one side.
Many years ago we sold the Super Screen made by FresnelOptics in Rochester, NY. This was a plastic screen that was frosted on one side to serve as a focusing screen and it had a Fresnel on the opposite side to give even illumination across the field. To protect the Fresnel surface from scratches/dust/fingerprints/etc. we also offered a cover glass with either a CM grid pattern and corners for 66/67/69/612 (Linhof 612 not the smaller ones) as well as a scale to comute exposure factors with image ratios to 1:1. This system has been discontinued for many years. The main reason that we discontinued it was that there were two long (5") unsupported sides on some camera systems and under high heat these could lead to the acrylic material bowing and no longer being positioned exactly at the film plane. This can be a problem with all plastic focusing screens.
At the same time that we offered the Super Screen Boss offered a screen made originally for film projection duplicating which was made from 2 layers of glass with a layer of paraffin between them.This also served as a combination gg/Fresnel type system but you had to use one made for your specific camera system so the wax layer was positioned properly at the film plane. So if you had a Linhof and wanted to use a Boss screen from another camera the wax layer would have been incorrectly positioned and you would have been out of focus by the thicness of the front piece of glass.
Very strange Bob. I've just checked and my screen on my Wista 45DX which is a one piece fresnel/screen with a protective cover and has the Wista brand name on it. They came with these screens as standard in the UK and I rang the UK importers for the price of a new one about 4 years ago but decided against getting one because they were quite expensive (it was for another camera).
B&H sell the same Wista 4x5 Groundglass/Fresnel Combination in the US.
Ian
Kevin Crisp
4-Jun-2012, 10:03
I've looked at the Canham GG side by side with the Maxwell and they look identical. I think they are identical. If you call the owner and tell him you have a Canham DLC and you're interested in a Maxwell he'll tell you not to change what you have. I did tell the owner I thought the Canham certainly looked like his product and he changed the subject. Other than cost, I can't fault the Maxwells, they are great.
The Maxwells and the Canhams I have seen are a soft plastic combined GG/fresnel with a clear cover on the back to protect it. No third piece is involved. I have one of the basic level Maxwell screens and the one which is one step up and supposed to be brighter. Only two pieces on all of them.
Bob Salomon
4-Jun-2012, 10:35
Ian,
They are not in our Wista factory price list or even mentioned on the Wista web site.
Wista's GG/fresnel jumped in price over the last year, based on B&H prices.
The fabulous GG/fresnel they make used to be around $160, now it's at just under $300.
Do you know what happened, Bob?
Bob Salomon
4-Jun-2012, 10:50
Yes,
From 2001 to this year we had not changed Wista prices. Then the prices caught up with the times and we had to raise them Feb. 1st.
Hugo Zhang
4-Jun-2012, 11:26
Who makes one piece fresnel ground glass? I know that Maxwell, Wista, Canham. Is there another manufacture? Which of those screens is the best?
Yanke? I have them in my Graflex Super D and Gowlandflex and they are not bad.
Hugo
Yes,
From 2001 to this year we had not changed Wista prices. Then the prices caught up with the times and we had to raise them Feb. 1st.
Fair enough; I wish it had been done gradually.
Thanks for the answer.
Yanke? I have them in my Graflex Super D and Gowlandflex and they are not bad.
Hugo
Ditto; mine is in a Technikardan 45, and it performs very well.
Bob Salomon
4-Jun-2012, 11:50
"Fair enough; I wish it had been done gradually.
Thanks for the answer."
So do we, but 10 years with no change in price could be called gradual, depending on your view point.
...At the same time that we offered the Super Screen Boss offered a screen made originally for film projection duplicating which was made from 2 layers of glass with a layer of paraffin between them.This also served as a combination gg/Fresnel type system but you had to use one made for your specific camera system so the wax layer was positioned properly at the film plane. So if you had a Linhof and wanted to use a Boss screen from another camera the wax layer would have been incorrectly positioned and you would have been out of focus by the thicness of the front piece of glass.
My impression of the Bosscreen was that it improved evenness at the expense of central brightness, by increasing dispersion. An advantage to it is no Fresnel lines. But the wax layer was reportedly not without its heat-related problems, in addition to the alignment problem that you mentioned.
The Maxwell improves both brightness and evenness, and the Fresnel lines are so finely molded that they are all-but inivisible, and no problem to focus through even with a 10x loupe. Another feature of the Maxwell is that the molded focus surface does not have the surface fractures that ground glass does, which looks like black grain through a small aperture. The Maxwell is even smoother than my acid-etched Sinar screen.
Yes, it's expensive. But especially for use with short lenses, it's worth it.
Rick "whose weak eyes benefit from a good screen" Denney
Sal Santamaura
4-Jun-2012, 16:54
The Maxwell (which I have) is actually three pieces: 1) GG; 2) fresnel; 3) protective cover glass.
I doubt you'll find a one-piece combination GG/fresnel since they require fundamentally different manufacturing processes...
Hi Leigh,
My maxwell is a combined ground glass and fresnel (a moulding with the fresnel on one side and his brilliant ground glass surface on the other). The cover glass is from my original ebony. I didn't know he made different ones...
...the Hi-Lux screen. It's one molded piece (with the focus surface--not actually ground--facing the lens and the Fresnel facing the user) and one sheet of clear cover glass.
Rick "who's never seen a Maxwell screen that used two parts for the focus surface and the Fresnel" DenneyBill Maxwell only offers his Hi-Lux acrylic combination focus screen / fresnel up to 5x7 inches. For anything larger than that, he says the screen is insufficiently rigid.
In sizes above 5x7, Bill sells fresnels that must be combined with conventional ground glass screens. They can either be placed between the ground glass and photographer's eyes, in which case they are susceptible to scratching, or between the ground glass and lens, which requires milling out the camera's back to account for focus shift, but protects the acrylic fresnel from scratches.
In my 6.5 x 8.5 and 8x10 cameras, I've installed Satin Snow glass with Maxwell fresnels over them. I'm sufficiently nearsighted that peering over my eyeglasses provides enough "magnification" to preclude needing a loupe, thereby mitigating the scratch risk.
Ian,
They are not in our Wista factory price list or even mentioned on the Wista web site.
Wista's GG/fresnel jumped in price over the last year, based on B&H prices.
The fabulous GG/fresnel they make used to be around $160, now it's at just under $300.
Do you know what happened, Bob?
Yes,
From 2001 to this year we had not changed Wista prices. Then the prices caught up with the times and we had to raise them Feb. 1st.
You've just told us you don't sell this combination Wista screen that we can buy from B&H and elsewhere, now you're telling me you've raised the prices for them.
Bizarre when you don't sell them.
The Wista website is awful, always has been, but these screens were in the Japanese printed English language literature I picked up from the UK importer in the mid 80's. I forget now the name of Teamwork's founder/owner, he died tragically young of cancer, but he was one of those rare genuinely nice helpful people, I bought quite a few things there. He told me one of his customers had wanted to sell his Wista, Teamwork couldn't pay what he wanted and make anything re-selling it and said sell privately via the BJP Classifieds (then very good). It never appeared instead a few months later a Wista appeared in AP, (an unusually rare purchase by then) so I called - same camera :D
There's something odd here Bob, I have to say you are always consistently helpful, knowledgable, etc, so I don't doubt what you're saying. Perhaps these are old screens the supplier has ceased trading but some places have spares in stock still. As the whole combo is plastic (fresnel/screen & protective cover plate) they maybe too difficult to break so few if any spares have been sold :D
Ian
Bob Salomon
5-Jun-2012, 03:16
Wista did package a sandwiched screen with a gg, fresnel and cover glass. That we did sell in the past.
But they did not sell a combination acrylic screen like the Super Screen with a frosted side on one side and a Fresnel side on the other.
Currently a sandwich screen is not in the Wista factory price list.
Sal Santamaura
5-Jun-2012, 10:01
Wista...did not sell a combination acrylic screen like the Super Screen with a frosted side on one side and a Fresnel side on the other...Perhaps Wista didn't sell a combination acrylic screen as an accessory, but that might have only been because they delivered cameras with one already installed. I'd have expected it to at least be available as a replacement from their parts department.
My first non-monorail metal camera, purchased in the early 1990s, was a Wista VX. I still have it. In January, 1994, seeking improved viewing, I bought and installed a Beattie Intenscreen in the VX. As a side note that's actually on topic, Maxwell screens are vastly better than the Intenscreen.
In the process of installing that Intenscreen, I removed and kept Wista's original acrylic one-piece acrylic focus screen / fresnel as well as the factory gridded cover glass. Attached are two images of them; the second is a bit tighter so one can see the Wista name molded right in the frosted rear, fresnel-ringed front (except for its center) screen.
Very bizzare as the Wista combination screens are still availbale from B&H and many of us have them fitted from new.
Ian
Sal Santamaura
5-Jun-2012, 20:28
...the whole combo is plastic (fresnel/screen & protective cover plate)...
...as well as the factory gridded cover glass...I should point out that the cover sheet which came from the factory in my VX (purchased new) is made of glass, not plastic. Grid lines are painted on that cover glass.
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