Initial Report: Maxwell Screen on Wista DX II

In the spirit of giving back to the large format community, I am posting my experience installing a custom focusing screen from Maxwell Precision Optics. I was unhappy with the Wista stock screen because while it is quite bright, it is a VERY directional screen. If I moved my head a bit from the optical axis, the screen would darken (worst with wide angle lenses). When I put a 90 mm lens on I found it almost impossible to focus.

In talking with Bill Maxwell, I learned that I could install the screen myself. I was previously under the impression that the fresnel was under the ground glass for this camera and so was concerned about getting correct focus point. However, Bill told me that he was familiar with the Wista and the fresnel was outside the ground glass.

Following his directions, I removed the cover glass and popped out the old screen. Since the new screen was not the exact size of the old one, I removed the strips on either side which held it in postion and replaced them with some black rubber material he had sent along. After cleaning the cover glass with Windex, I reinstalled it.

Compared to the stock Wista screen, the Maxwell screen isn't quite as bright, but it is MUCH less directional. The fresnel lines are very fine, about like those on the Tachihara I previously owned. It is more directional than the Tachihara screen, but also much brighter. I would say that it is probably the best compromise between brightness and directionality. I had no problem focusing a 90 mm lens, and the image was relatively even across the field--not much of a "hot spot" (the stock Wista screen was terrible).

Conclusion: while the screen isn't cheap, I am very happy with it so far. It is better than either the Tachihara or Wista stock screens by a significant margin.

I have also used the Maxwell screen on an Ebony 23S. The screen didn't appear to be significantly brighter than the stock Ebony fresnel, but did have a much more even illumination with wide lenses. Also, the most important factor to me was that the harsh circular fresnel lines that previously hampered my focusing were all but gone. The Maxwell screen is much easier to look at under a 6x loupe than the stock screen. Installation was a breeze as well. Another happy Maxwell user.

When I spoke to Bill, he suggested that his screens are optimized for a particular focal length lens, and performance is (somewhat) compromised with other lenses. Do you know what focal length your screen was optimized for?

No, I don't. I told Bill that I wanted to use lenses from 90 to 300 mm. My understanding is that he has a "standard" screen that is set to handle that range, but you can get other screens to meet your needs. My screen is the "Hi-Lux 4.7 Brilliant Matte Focusing Screen for 4X5 cameras".

John,

Do you have a Wista that was purchased new or used? Is it a current product or an older product? The manufacturer changes there GG and fresnel screens as improved ones come along. In addition Wista also makes a special fresnel just for long focal length lenses.

Do you know which Wista frenel screen you had?

Lastly Wista uses a sandwiched construction for their GG and frenel screens consisting of the GG, the fresnel and either a clear or ruled cover glass. Is this the way your GG and fresnel was installed?

My Wista was purchased used, but was bought new in July, 1999 by the person who sold it to me. My Wista had two parts, a sandwich part which is GG and fresnel screen, and a clear cover glass. The GG was facing the camera lens, the fresnel was on the outside under the cover glass. The Maxwell screen had the same design of GG toward the lens and fresnel on the outside (right under the cover glass).

But what fresnel was in it?

And did you happen to try to compare what yours looked like vs a current Wista system?

The fresnel was engraved with "Wista", so I am sure it was the stock screen.