Help with Ground Glass location

[gurrie]

I have a very nice Technikarden TK45S and it came with a fresnel lens behind the ground glass. I tried to get used to it but do not like how fuzzy it looks when I focus with my 4x loupe due to the concentric rings.
i just bought a Satin Snow GG and noticed that when I took off the fresnel lens there are 4 little shims behind the ground glass on the back. My question is where do I reinstall these shims when I receive the new GG? Were they just for the fresnel lens mounting or are they part of the TK45S original factory mounting. There is not much help with the Linhof stuff is there!!!
Any info will be greatly appreciated.
Thanks in advance.

 

[photobackpacker]

Clarify what you mean by saying the fresnel lens was BEHIND the ground glass. Do you mean that the fresnel was between the ground glass and the lens or it was closest to the photographer when viewing the image.

 

[PeterDendrinos]

You will notice if you look closely. That there are 4 little set screws under the glass. Those “shims” go on top of the set screws, and the GG lies on top of them. Keep in mind you may need to readjust your new GG to align it with the film plane.

Drop me a line if you need more info.

Pete

 

[Donald Miller]

You will notice if you look closely. That there are 4 little set screws under the glass. Those “shims” go on top of the set screws, and the GG lies on top of them. Keep in mind you may need to readjust your new GG to align it with the film plane.

Drop me a line if you need more info.

Pete

You should not need to reallign the ground glass so long as the ground glass front surface location has not been altered.

 

[MichaelBriggs]

If by "fresnel lens behind the ground glass" you mean that the Fresnel lens is between the ground glass and the photographer, and not between the lens and the ground glass, then you can remove the Fresnel lens without effecting the focus. The image forms at the ground surface, and optics on the photographer side of the ground glass don't change this. You can switch between different brands of regular ground glass by simply laying the new ground glass on top of the existing metal strips. In both cases the ground surface will be positioned in the same place, and that is what matters.

Some advanced screen are more complicated because they have a built in Fresnel. The Boss Screen is more complicated because the image forms inside the sandwich. Also more complicated is the situation where a Fresnel lens is placed in front of the ground glass, on the side that faces the taking lens. As long as none of these are involved, either before or after, swapping ground glasses should be easy. Of course, a photographic test wouldn't be a bad idea.

On your TK45S, the four metal strips aren't really shims. As Peter says, the metal strips actually sit on top of screws, so if necessary, the ground glass position can be adjusted by turning the screws. The was a longer discussion at http://www.largeformatphotography.info/lfforum/topic/501030.html.

 

[gurrie]

thank you all for your help. i am planning to buy a zig align tool to check the parallism of the gg to the fp.
aobtw the shims are between the gg and the lens side of the camera.
ed