Linhof to Sinar Adapter boards

[Ron Bose]

The original Linhof Technika lensboards have an off-centre drilled hole to accept the lens/shutter. So when an adapter board is fabricated specifically for Linhof to Sinar, why is the smaller board always placed centrally ? Hence the lens axis is a little lower when mounted on the Sinar.

Is there any real value in having an adapter fabricated with the Linhof board positioned higher up so that the lens axis is central ?

Thanks in advance ...

[Bob Salomon]

"The original Linhof Technika lensboards have an off-centre drilled hole to accept the lens/shutter."

Not necessarily so.

If you look at the front of the board the hole appears low. If you turn the board over the hole is milled in the center of the light trap on the rear of the board. This is the actual area that fits into the hole in the camera's front standard. So while it appears low to a Technika or TK it is actually centered in the hole and zeroed on the center of the gg when the front and rear standards are in the 0 position.

While only Sinar can answer why they place the hole where they do on their adapter we checked the Kardan to Technika and the M679 to Technika and the they are made so they line up properly on their respective cameras.

In practice with other then very short lenses any off-centering with your adapter should not create a problem.

Of course with wide angle lenses it could be a problem as the lenses have a hot spot and you will no longer have the hot spot ceneterd on the film. In practice this may not bother you as Linhof has intentially mounted the lenses (58 and 135mm) on the Technorama 612 8mm off center to give the effect of lens rise. While most users of the camera with the 58mm use the center filter no one has ever come back to us to complain about uneven coverage due to the offset 8mm.

[Dave Schneider]

When I made my Technika to Sinar adapter I made it so the lens will line up with the center of the Sinar board. I also built it so the lens would be position in exactly the same spot fore and aft, in other words the Technika board is flush with the surface of the Sinar board. This wasn't really necessary, it just looked nicer and actually made fabrication a little easier.

[Juergen Sattler]

I just had two Linhof to Sinar Lensboard Adaptors made by SK Grimes and they took the lower Linhof holes into consideration. My lenses on the Sinar board sit now dead center as they did before I put them on the Linhof boards. SK Grimes did a really nice job with these adaptors - highly recommended!

Juergen

[Kerry L. Thalmann]

If you turn the board over the hole is milled in the center of the light trap on the rear of the board.

This statement is incorrect. I own several genuine Linhof lensboards, and when I turn them over the hole is obviously milled below the center of the circular light trap.

However, this is by design. As Bob correctly stated, the below center position of the mounting hole is required to mount the lens so that it will line up with the center of the ground glass on Linhof cameras.

Kerry

[Ron Bose]

Thanks for everyone's input.

I have cancelled my order for an 'unadjusted' adapter board and will ask SKG to make me one which centres the resultant position of the Linhof drilled hole in the centre of the Sinar adapter.

This will make life easier alround and I won't have a permanent 'fall' movement set everytime I line up the Sinar to it's zero position.

It will also make life easier when I use it on my 8x10 as well ...

Thanks again.