I found a Great focusing screengreenspun.com : LUSENET : Large format photography : One Thread
Just thought I'd share information about the focusing screen I bought for my 6 x 9 Horseman VH. I bought it from Bill Maxwell at Maxwell Precision Optics, (404) 244-0095. He makes focusing screens for all size cameras. His screens are wonderful and very reasonably priced, all considering. All Bill's screens are custom fitted to your camera, lenses and shooting style. They're very fine grooved fresnels, that are extremely bright and contrasty. When I focus using my 4x Schneider loupe, the fresnel lines are barely noticeable because they're so fine. Bill truly understands optics and can explain much better than I can, but, in short, in an ideal world, we would have separate fresnels for each lens. I compromised by getting two: one for my 58 mm XL and 75 mm, and one for my 135 mm and 240 mm lenses. The one that's optimized for the longer lenses also works very well with the 75 mm. The screen for the 58 mm is amazing. No light fall off in the corners. It's so bright I can focus with just the pop up focusing hood. I've shown them to a guy who owns the local camera shop who is a fanatic (he owns about 30 cameras) and he says they're nicer than anything he's seen including the Boss screen and the various bright screens. Bill Maxwell also designs screens for a few very high priced large format camera manufacturers. My screens, fitted to the backs, including shipping were about $150 each. Considering the many phone calls, patient explanations, personal service, and great product, I consider it a bargain. After looking for the perfect screen for the last 4 months or so, I've found it (or them since I ended up getting two).
-- Howard Slavitt (email@example.com), May 28, 1999
Howard thanks for the tip. If I understand you correctly you got a back or at least a groundglass frame for each of these screens. Is that correct?
-- Ellis Vener (firstname.lastname@example.org), May 28, 1999.
Yes, Ellis. I put the screen that Bill recommends for 4 x 5 users who only want one screen to use with a wide variety of focal lengths (the one that works best with the 135 and 240 mm lenses and also works well with the 75 mm lens) in the normal back. I have the screen maximized the 58 mm in the monoreflex viewer frame. It is so bright and contrasty that it makes using the camera with the monoreflex viewer seem like I'm using a modern SLR. BTW, I've been using the screens for about a month now, and my slides have all been dead on sharp; it makes focusing (and composing) very easy.
-- Howard Slavitt (email@example.com), May 28, 1999.
Howard, I've called Bill twice today and always get their answering machine. I'm beginning to get concerned about the "patient explanations, personal service, .." comment. Are they typically that hard to get in touch with?
-- Carlos Co (firstname.lastname@example.org), May 28, 1999.
Bill has always gotten back to me within a day of leaving him a message on his machine. Once you talk to him I suspect you'll see what I mean. He is very patient to explain the optical principles involved with the various focusing screens. He also consults for various manufacturers and has, it seems to me, tested pretty much every screen out there at one time or another.
-- Howard Slavitt (email@example.com), May 30, 1999.