Bosscreen + Fresnel adaptable on Toyo VX-125?

[Paul Schilliger]

Has someone successfully mounted a Bosscreen on a Toyo VX-125? The GG-Fresnel co mbo of the VX is not bad at all, but I do miss the clear spot at the center and also the possibility to focus with a loupe without shading, that the Bosscreen a nd some other Fresnel combo (Horseman) provide. But it seems to me that mounting a Bosscreen on the Toyo would mean having to renounce the Fresnel. Any experien ce?

[Bob Kramer]

I know this doesn't exactly answer your question, but if you can't find a Bosscreen to fit your camera you might want to talk to Bill Maxwell (404-244-0095)about one of his focusing screens. I just got one of his screens for my 2x3 Galvin camera for which, due to the funky design of this "masterpiece" of medium format engineering ;-), Bill had to cut a custom size screen. It is amazingly bright. Most of the time I no longer need to use a dark cloth, and you can easily focus without shading the loupe.

[Peter Shier]

I second the motion on Bill Maxwell's screens. I got them for my 4x5 and Hassy and they are simply superb. Bill is also a really nice guy and will spend time explaining everything to you.

[andrea milano]

I have no reason to think that Maxwell's screens are anything less than perfect, if on the other hand, you still prefer the bosscreen(my choice because I am not aware of any European sources of Maxwell's products), they are available in any size.

[Paul Schilliger]

Thanks! Just to precise, the problem on the Toyo is that the fresnel is placed b efore the GG. The Bosscreen will fit into this space, but being thicker, will occupy the space needed for the Fresnel. And there is nothing to hold the Fresnel on the other side, but this can perhaps be remedied. Is there a website for Maxw ell products? Are they universally used, for wide and long lenses as well?

[Bob Kramer]

Paul, I don't think Bill has a website so you need to just give him a call. He will ask you a lot of questions about your equipment and what lenses you use in order to suggest what he feels is the right screen for you. I think he would suggest differenct products depending for instance on whether you mostly shoot with wide angle or long lenses. In my case, he also wanted to know what kind of movements I used with the wide angle lens that I use most often. Apparently the amount of rise movement I typically use led him to suggest a different type screen than what he was originally thinking would be best for me.

Bill does sell internationally, and is a really nice guy with an (to me, at least) amazing amount of knowledge regarding focusing screens that he is more than happy to share.

[Sal Santamaura]

Paul, before me is a sketch, faxed from Toyo's factory in 1997, showing their 4x5 camera backs. Dimensions included are distance to the groundglass matt surface (5.25 mm) and an offset of 0.5 mm partway through the fresnel, resulting in a line at 4.75 mm - - 0.187" - - labeled "Actual Focal Plane." There's no indication of how thick the fresnel is, but, if you measure yours with a caliper and subtract 0.5 mm, you'll know exactly where your focal plane should be located, regardless of what option (Maxwell, Bosscreen or other) you select.

[Paul Schilliger]

Thanks for the info!

[Sal Santamaura]

You're very welcome. If any of the that was unclear, just ask for further explanation.

[Larry Huppert]

Paul,

On the Toyo is the fresnel on the lens or eye side of the GG? If it's on the eye side, a properly shimmed Boss screen should be able to replace your GG. If memory serves me, a fresnel on the lens side of the GG will modify the location of the focal plane. If you remove the fresnel, and only have the Boss screen your going to have to be real careful that your focus isn't messed up.

The screen on a Canham DLC and a Maxwell are real similar. I ended up replacing my Canham fresnel with a Boss screen. They are entirely different products. As your probably aware, the Boss screen is *real* fine grained, but brightness isn't one of it's strengths. The Maxwell screens are very good fresnel screens, but it doesn't have anywhere close to grainless look of the Boss. Actually on my DLC, I've married a Boss screen with a clear removeable Maxwell fresnel which I place on the eye side of the Boss. If I shooting in bright surroundings, I just use the Boss. If it's more dim, I'll put the Maxwell in place for composition, but then remove it for fine focus.