Dark focusing screen -- solutions?greenspun.com : LUSENET : Large format photography : One Thread
I just bought a used Horseman VH (6 x 9) technical camera. The focusing screen is pretty dark, especially at the corners, and worse when using wide angle lenses. It doesn't have a fresnel in it, but I can order one from the manufacturer. Should this help? I read the threads concerning the various brightening screens and found the reviews inconclusive. It sounds like the Boss is the best, so maybe it's worth $150 to try it. Nobody seems to like the Beattie Intensescreen for large format, although I had one on a Nikon F3 years back and had really liked it on that camera. I'm leaning towarding trying the Horseman fresnel first (it only costs about $30) and then if I don't like it, I'll spend more bucks on a Boss or Beattie. Also, I'm going to get a black cloth from Darkroom Innovations (instead of my jacket); hoping that will help. Any other ideas? BTW, I also have a monocular focusing viewer (which looks to me to have a built in fresnel lens) and that was also pretty dark in the corners when using a wide angle lens. Are these types of complaints about the viewing screen normal for someone who's new to view camera photography?
-- Howard Slavitt (email@example.com), November 01, 1998
Hi Howard, When I started LF photography I had same complaints as you have. A good focusing cloth will help you. I think using a jacket is not good idea particularly when you are in bright condition. As for fresnel screen, it will brighten corners a little when you use wide angle lenses, however, it may make difficult to evaluate definite focusing for diffused light. I recommend you to use a focusing cloth first. I use a Boss on my 4x5, but just plain grandglass for my 8x10 with no problem.
-- Shigehiro Ishii (firstname.lastname@example.org), November 02, 1998.
I agree that you need a decent dark cloth for openers, and the one sold by Darkroom Innovations is excellent. Next I would try the fresnel lens just because of its price. See how you like it - if things still look too dim you could try the Bosscreen but you need to realize that the Bosscreen strictly speaking isn't a "bright screen." What it does is spread the light out evenly around the ground glass (a non-technical description), thus allowing you to see and compose somewhat better than with just a ground glass. I had the Bosscreen on my Technikardan and it was a big improvement over the plain ground glass that came with the camera. For me, the plain ground glass was useless - I had to keep moving my head around to find the bright spot and I couldn't view the entire scene at once and so couldn't compose anything.l The Bosscreen is also better than a fresnel lens when using a loupe because the loupe enlarges the circles in the fresnel lens, thus making it a little more difficult to focus. Again, though, if the fresnel lens is only $30, and the Bosscreen is around $150, why not start with the fresnel lens?
-- Brian Ellis (email@example.com), November 02, 1998.
Brian -- have you or anyone else used the Linhof "Super Screen?" How does it compare with a Fresnel or Boss screen?
-- Henry Stanley (firstname.lastname@example.org), November 04, 1998.
For what it's worth, I've use a Beattie on a Pentax 67 and on a Tachihara. As a comparison, I now have a fresnel with my Toyo AX.
Without doubt the Beattie is brighter. In fact, with a Tachihara and a fresnel placed right beside my Tach. and Beattie, it measured 1 stop brighter in the sky (top center of the frame).
It was slightly more difficult to focus the Beattie but the overall focusing (corners) was easier.
IMHO, if the darkness bothers you, don't hesitate to add a brighter screen. Pay some attention to requirements of installing the screen as on certain cameras the plane of sharpest focus will change and your camera must be adjusted to compensate
-- Mike Long (email@example.com), November 04, 1998.
For what it's worth, since my original post, I've obtained an Arca Swiss 6 x 9 fresnel, which fits the Horseman after it's sanded down. The image is now much brighter and easier to focus. The corners are clearly visible and evenly illuminated. Although the fresnel lines are a bit distracting when focusing, IMO it's well worth the compromise and cost.
-- Howard Slavitt (firstname.lastname@example.org), November 04, 1998.