I recently acquired a Nikon SW 120/8 to use as an ultra wide on my Canham 8x10 (with fresnel lens). Naturally, when the lens arrived I simply had to look through it. The first thing I noticed was a terrible double image off axis. It gradually gets worse the farther from the center of the ground glass I look. The double image is so bad in the corners that I can't tell if the image is in focus.
Being curious by nature, I put a 150mm lens on the camera and carefully checked the corners of the GG. The double image effect shows up with this lens too although it's much less noticable and it's easy to check the focus in the corners. I can even see a very slight double image in the corners with a 210mm.
I haven't shot the 120 yet but images taken with the 150 are sharp to the corners with no sign of the double image on the film. This leads me to believe that the double image is being caused by wide angle lenses and the fresnel. Is that possible? I've never seen this effect on my Tachihara 4x5 (also with fresnel) using lenses as wide as 55mm.
On the Canham the fresnel lens is located in front of the ground glass, nearer to the lens, that is. If I remove the fresnel would I need to shim out the ground glass?
Are there any other solutions? I suspect I'll really like the extreme wide angle view of the 120 but currently it's almost unusable.
Thanks for your help.