Fresnel Lens Question

I have a new-to-me Linhof 4x5 ground glass back that doesn't have a Fresnel lens. Has anyone tried using one of the thin, soft plastic fresnels from places like Edmunds or Ultraoptix instead of the "official" manufacturers fresnels? I'm wondering if the angle and spacing of the grooves is critical. (Registration is not an issue with these backs, the fresnel goes on top of the factory set ground glass.)

Thanks,

Tim

You have to remember Fresnels are lenses in them self, hence they have a focal length that is optimized to a certain length lens, but I am sure you will be able to find something that will give you a better view, depending on what your going to use for a lens.

Dave Parker
Satin Snow Ground Glass

I bought a Linhof Technikardan 45 used about three years ago. I felt the ground glass was too dark for me to see much at the edges. This proved out while photographing my white 1955 Porsche Speedster in a well lit studio with a 90mm Rodenstock Grandagon-N f4.5. It doesn’t get any lighter than that. My mentor was using his Linhof 8x10 studio camera and everything showed as bright as a TV set. He saw a large sand bag by the tire in a head on (front) shot. I had already made the shot not seeing the bag on the edge on the gg. Fortunately there was time to move the sandbag and re-shoot.

I found this question had been explored before on the LF pages and by Paul Butzi http://www.butzi.net/reviews/linhoftk45s.htm. On their recommendations I bought the BosScreen . I found mine new on Ebay, but Bromwell Marketing in Pittsburgh imports them from the Netherlands. http://www.bromwellmarketing.com/. Yes it costs more than what you are looking at, but can you always re-shoot what you didn’t see? How often can an amateur borrow a studio with a 10x20 soft box hung from the ceiling and have a pro looking over his shoulder?

John Powers