Not so sure about this Fresnel lens

[Laminarman]

On my new F2, I ordered the fresnel lens, which sits atop the GG. I have to be looking quite DOWN at it, not head on, to get a bright view. Also, is that hole in the center there for a purpose? If I line myself up square to the camera it's pretty dark, only when I'm above center quite a bit is it brighter. Is that normal? Not sure if I should take it off and try without it, I hate monkeying with something already, only got it last night.

[Doremus Scudder]

Some photos would help...

Normally, if you have to "look down" to see the image, the lens and film are not aligned (e.g., the lens is lower than the optical center or tilted back, putting the optical center lower). Make sure your camera is in zero position, remover the Fresnel and see if the image is correct on the ground glass. If so, you may be installing the Fresnel improperly, i.e., not parallel to the ground glass.

Is the "hole" in the center of your Fresnel actually a hole? Or is it just a smooth surface without the concentric rings? If the latter, most Fresnel screens are designed like this to give you and area of fine focus in the middle.

Hope this helps,

Doremus

[Laminarman]

Doremus, it was installed by Chamonix so I left it alone. That being said I took it outside in the snow just now and took a distant shot, and it was perfectly fine. The camera was lined up. What I did earlier was an indoor, pointing down at a table and had some tilt and rise employed , so not sure if that was it. So outside it was just great, f5.6 lens, cloudy nasty day. I'll try inside again this weekend and see if maybe your thought about OC is the issue. I underexposed the negatives, but they are evenly underexposed, no vignetting.