Linhof TK GG & Fresnel Replacement

**LarryT** · 22-Mar-2014, 08:16

I need to remove the groundglass and fresnel on my Linhof TK23 for cleaning and may want to replace the GG while I’m at it. This brings up the question of which GG to get and a few procedural questions:

1) The Linhof pricing sheet lists two different groundglasses, and one with a clear center spot. What is the purpose of the clear center spot?

2) To remove the GG, the TK23 has two plates that hold down the GG, there are three screws in each plate but it looks like only the two outer ones hold the plate, so what is the center screw for?

3) Another forum thread indicated there were four positioning screws under the GG to correctly align the GG and that there MAY be spacers on these screws, do they exist on the TK?

4) There appears to be just one fresnel retaining clip, what is the best way to remove the clip and the fresnel without damaging the fresnel?

Thanks for any help anyone can provide, just trying to make sure I don’t screw anything up!

Regards,

Larry

**Ari** · 22-Mar-2014, 08:23

Larry,
I just received my TK45 back from Blazes, the Canadian Linhof repair shop.
I needed a new GG/fresnel and the GG/fresnel also needed to be calibrated, so I sent it to the pros.
I'd suggest you contact the Linhof service centre in the US, can't remember the name, but I believe they are in New York.
They can answer all the questions and install the GG correctly, which is a little tricky on a Linhof.
In answer to question #2: the centre screws are meant to hold a fresnel, and work in such a way that the fresnel can easily be removed for critical focusing, or when a fresnel is not needed.

**Bob Salomon** · 22-Mar-2014, 08:44

1: The center spot was primarily used for macro and micro photography.
2: You remove all 3 screws on 1 plate and loosen the ones on the other end. That way, once you lift off the one without the screws you can slide the GG out from under the other hold down bar.
3: These are on all Linhof 45 cameras.
4: The modern Linhof cameras have a sliding silver metal clip screwed onto the middle screw at either end. To remove the Fresnel, or install it, you just swing them to one side. Older cameras had a lift-up Fresnel clip which was an option. To remove either type, lift off the Fresnel and unscrew the screw holding whichever clip you have from the hold down bar.