Fresnel Ground glass

[Songyun]

Who makes one piece fresnel ground glass? I know that Maxwell, Wista, Canham. Is there another manufacture? Which of those screens is the best?

[Leigh]

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

[Songyun]

I have a Canham screen and a Wista. Both one piece, requires protective glass.

[timparkin]

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

[IanG]

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

Ian

[Ari]

I think Tachihara also makes a GG/fresnel that requires a glass overlay.

[Songyun]

I had Canham, and had Wista, never had Maxwell, never compared them side by side. Has someone compared these side by side?

[rdenney]

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 - HP Marketing]

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.

[IanG]

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