ArcaF/Maxwell screen report

[Daniel Geiger]

Here's a short report on how the focussing screen by Bill Maxwell works on an Arca F-line with 141 standards. Maxwell makes after market focussing screens that are supposed to be quite bright (see other threads on this forum), as replacements for OEM screens. A potential problem with the Arca is, that the Arca uses a fresnel/ground-glass sandwich, so the question of focus shift arises, when one replaces the Arca sandwich with Bill's single screen (plus protector glass).

I tested it with a desk-top set-up, using my new Rodenstock 180 mm Macro Sinaron wide open at about 1:1 and focussed on a slanted surface on the tip of a pencil with the OEM ground-glass/fesnel. After locking everything down, I unscrewed the OEM pieces, and put the Maxwell groundglass/protector glass in. The focus stayed exactely the same. In theory, the removal of ~ 2 mm fesnel should cause a focus shift of ~1/3 of its thickness = 0.6 mm, which is definitely noticeable. But I could not see a focus shift with a 6x loupe, and I could not improve that focus at all. I want to emphasize that this is not a test with lasers on an optical bench, but what you will actually see when you use the equipment for picture taking.

What I did notice is the brightness of the screen, looks about 1 f-stop brighter. What a difference! Took it out for a spin today to shoot some mushrooms and a Peonia. The screen performs just as well outdoors. In the past when I checked the corners of the screen, I had to tilt the loupe and look from the outside towards the center of the screen to get reasonably bright image. With the Maxwell screen, it's rather the reverse: to check the corners you look from the center of the screen out, which is much easier as I hardly have to move my head around.

I also use Ron Kulkas' ground glass protector (piece of moded plastic). The Maxwell pieces are a bit thicker than the OEM, so to make it fit again I had to file a groove in Ron's potector, which took the better part of 2 minutes.

So, if any of you Arca users wondered about it, here's the answer. Keep the Arca pieces for back-up.

[Bruce Watson]

I've got a Maxwell screen in my Toho. You gotta love these screens. Very nice indeed.

[Doug Dolde]

Good report. My Field (171mm) has such a good screen I would not have thought Bill's would be better.

On a crappy Ebony yes but an Arca?

[resummerfield]

The Arca has their fresnel between the gg and the lens, and I think Arca has separate mounting tabs or pads for their gg and their fresnel. So when you installed the Maxwell screen, did you place it on the tabs for the Arca gg or the Arca fresnel? Were there any factory installed shims, and if so, did you remove them or leave them in place? Thanks!

[Brian Ellis]

When I bought a Maxwell screen for my Master Technika the screen came with some replacement screws and shims as I recall, together with instructions for mounting the screen. Did you get nothing like that? I've used almost every brand of screen there is I think, from plain ground glass to Beattie to Linhof Super Screen, to OEM Fresnels, to BosScreens. Maxwell is the best of the bunch IMHO. The only thing even close is the BosScreen.

[KenM]

Well, that about does it. I think I'll be getting a Maxwell screen for my MT - thanks a lot, Brian, geez. :-)

I made the mistake of calling Bill Maxwell on the phone a few weeks back. Man, can that guy talk. And talk. And talk. But it appears that he knows what he's doing with respect to screens...

[Frank Petronio]

I can't imagine a better screen than what is standard on the Arca... How is the Maxwell with wide angles? The Arca was excellent with all my lenses.

Really though is there a way to measure? Because I really thought the Arca screen was the best ever and I can't imagine something brighter and better unless is radioactive or magical.

[Leonard Evens]

I use my Maxwell screen with lenses from 75 mm through 300 mm on my Toho FC-45X. It works fine with the 75 mm lens.

[Daniel Geiger]

E. Summerfields: Indeed, the fresnel is mounted in a small depression towards the lens, while the gg lies above that, supported by different set of place-holders. There were no additional shims, except for the milled depressions/place-holders in the rear standard. I placed the Maxwell screen exactely where the ARCA screen was before, ground surface towards the lens, and the protector glass away from the lens. The screwed-in metal clasps got a bit deformed, when I tightened them with the Maxwell pair in, because it is a bit thicker than the ARCA gg alone. As the clasps are made of some thin, deformable strips of metal, there was nothing to worry about.

Brian Ellis: The Maxwell screen came along with instructions on how to mount it. I called Bill once, and got an extremely detailed explanation on the various factors. An other customer apparently told him, that the Arca told that customer that the Arca did not need any adjustments due to the removal of the fresnel, but Bill could not quite understand that, so cautioned me about it. That is also why I did my table-top test, to see what adjustment would need to be done.

Frank Petronio & Doug Dolde. Well, I was also wondering how good it could be. I was in for a hefty (good) surprise. It IS magical! (though hopefully not radioactive) Went out today again. Used it with my 90 XL (my widest), and it is just gorgeous. The image is also cleaner-crisper than with the Arca gg. Bill apparently makes a different screen for ultra-wides, where the 90 is just a border-line case. I have the "regular" version.

[Harley Goldman]

I have the Arca F-Line Classic and the Toho with a Maxwell screen. I set them up side by side and compared the brightness of the two screens with the same lens. They seemed very, very close. I was not inspired to get a Maxwell for my Arca, but on the Toho it makes a huge difference.