View Full Version : Technika rangefinder focusing problem

27-Dec-2003, 08:32
Hey there,

Maybe there is someone who can explain the problem i'm having with my Linhof Technika IV. Couldn't find it in the archives...

I've checked the rangefinder focus on the groundglass and there is a significant difference between the two. I'm using a linhof/schneider 150 mm with the correct cam. I'm thinking the following:

-some misalignment in the rangefinder system -groundglass not aligned right

Any ideas? thanks in advance!


Bob Salomon
27-Dec-2003, 08:40
1: The cam has the serial number of both the camera and the lens? If not you need a new cam. 2: Is there a fresnel screen installed or an enhanced viewing screen? If so is the fresnel below the ground glass as the IV was designed for? Or is it on top of the GG. 3: If the screen was changed was it properly installed or was it just dropped in? 4: Have the ground glass shims been adjusted by other then a qualified technician? 5: The back is the original one from the IV and not a newer one from a V or Master?

27-Dec-2003, 11:46
It could certainly be what Bob said. Or more likely it could be that the infinity stops are incorrectly positioned, and need to be reset (an easy job). (One out of three lenses on my IV came installed with that problem.)

Bob Salomon
27-Dec-2003, 12:09
Before you start playing with the infinity stops you should bear in mind the following. The infinity stop screws have sharp points so they "eat" into the chrome rails they are mounted on. When you move the stop you will leave small, permanent, marks on the rails. If your cam has matching serial numbers for your camera and the lens then your stops are probably properly placed. If the numbers don't match you need a new cam. If your rails show a series of small pock marks then your stops are probably improperly installed due to use of the wrong cam. To solve the problem service should reset the stops and make a new cam.

27-Dec-2003, 12:30
thanks for the help everyone. Here's what i can answer:

-I'm using the correct cam for the lens (serial number matches)

-the fresnel. Now that's a good one. I am using a fresnel AND i've changed the groundglass. Here's the setup: i've removed the original groundglass and replaced it with a bosscreen, wich as you probably know is a double layer of glass. The focusing plane is a layer of parrafin wich is at the same position as the original groendglass. On top of that (so on the outside of the groundglass, not on the lens side) i use a fresnel. It was at this position when i got the camera, so i never checked if this was correct. also, if i were to place it on the other side, wouldn't that move my focusing plane to a incorrect position? I placed the bosscreen myself, but it is a snug fit and it seems impossible to install it in the wrong position.

Furthermore, the back of the camera is original. And i cant find out what "groundglass shims" are. So if you have any more advice...



27-Dec-2003, 13:19
Off to Marflex to have the Bosscreen properly fitted.

Bob Salomon
27-Dec-2003, 13:27
Ditto. Send it in for service. You can call them at 973 808-9626. Their address is Marflex Service 16 Chapin Road Pine Brook, NJ 07058.

And with the Boss screen why add a fresnel screen?

The shims are the adjustable metal rectangular pieces the ground glass sits on. They are still there I hope.

27-Dec-2003, 13:45
ok guys. I'm sitting here and i have the camera back in front of me. It could very well be the groundglass but i don't understand how it could be improperly fitted. This is what i'm seeing:

the groundglass sits on both sides on a raised edge milled out of the camera back. there is nothing adjustable there, just two 'steps'. the bosscreen rests on the upper step. When the groundglass is inserted, it 'falls' on these steps and really can't go anywhere else. So what could go wrong?

And does anyone know the proper postion for the fresnel? is it on the lens side, so resting on the lower step/edge or is it on top of the groundglass, so on the viewers side?

thanks again,


Bob Salomon
27-Dec-2003, 13:51
Someone has removed the 4 shims apparently. They sit on 4 very smalladjustable pins.

On the IV the fresnel was installed under the ground glass. On the V some were under and some were over. On the Master the fresnel sits over the ground glass.

Since someone has removed the shims - and possibly the pins - your camera needs service to re-position the focusing screen where it belongs.

29-Dec-2003, 15:01
Ok guys, thanks for the help. I'll have it checked out!