How accurate should a Linhof Rangefinder be?

[Mrsmartacus]

Dear All

I've recently purchased a used, but in pristine condition Linhof Master Technika. I'm familiar with large format cameras and am fairly sure I'm following the instructions correctly but it appears that when I focus using the rangefinder, the image is out of focus on the GG (and vice versa). I've extended the bed until it clicks in, pulled the lens board out to the infinity stop and ensured that all movements are zeroed. It's out across the entire focussing range - from near by to infinity but only by a small amount - around less than a 1/8th of a turn of the focussing ring. I estimate that at around 10ft the difference between the two focussing points is around 1ft. Some of this variance will of course be made up by depth of field when I stop the lens down, but I would have thought that the range finder would focus on the same point as the GG screen. My sense is that its enought to make a difference when undertaking portraiture and one of the reasons I purchased that type of camera was the rangefinder and its ability to focus quickly and accurately without resort tot he GG screen and a dark cloth.

I guess my question is: am I doing something wrong, how accurate should the RF be and should I get it recalibrated?

Many thanks in advance

Andrew

[Bill_1856]

Properly set up, technika rangefinders are superb.
First, check that your cam is fully slid home against the post that determines infinity location. If that is right, then check that the cam number corresponds with the serial number of your lens.
If both of those things are okay, then the problem is the infinity stops on the camera rails, and you will have to move them so that the lens is in focus at some point which agrees with the rangefinder.

[David A. Goldfarb]

Have the camera looked at. Both the groundglass and the rangefinder need to be calibrated so that they agree and match the film plane, and the stops need to be set accurately. Also, be sure there are no obvious problems like one of the lens cells being partially unscrewed.

Meanwhile, you might also make some focus tests on film. Shoot wide open with the camera on a tripod, using a known target positioned with a ruler along the lens axis and see which is more accurate. It could be that the rangefinder is correct, and the groundglass is not.

[Leigh]

It could be that the rangefinder is correct, and the groundglass is not.
The groundglass is correct by definition unless the camera has been damaged.

If the infinity stops are set for a different lens, it will affect the rangefinder calibration, but the groundglass focus should still be correct.

The infinity stop must be at the correct location for the lens in use.
Some cameras of this type allow installation of multiple infinity stops for different lenses, with unused ones flipped up out of the way.

- Leigh

[David A. Goldfarb]

The groundglass is correct by definition unless the camera has been damaged.

If the infinity stops are set for a different lens, it will affect the rangefinder calibration, but the groundglass focus should still be correct.

- Leigh

Not on a Tech V or a Master Tech. There are are screws that allow for the fine adjustment and squaring of the groundglass. The reason that cams are interchangeable on a Tech V or a Master Tech is the groundglass is "zeroed," which is not true on a Tech IV or III. On the earlier cameras, the cam is calibrated both to a single camera body and a single lens, and cams are not interchangeable between camera bodies.

If you want to be able to purchase, say, a used lens with a Tech V/Master Tech cam, you'll want to be sure the groundglass really is calibrated properly as well as the rangefinder, and you're not just fudging it by adjusting the infinity stops, or you won't be able to count on all the cams to focus accurately.

[Neal Chaves]

Be sure the lens is focused at infinity when on the stops and with the track all the way back. If it is not focused correctly, either not reaching, or going beyond infinity focus, the stops are not set correctly. Before doing anything, try this. Fold down the stops and position the lens on the track for correct infinity focus. Now try range finder focusing and see if it agree with the ground glass. If it does, simply reset the stops. Of course, any number of things could be wrong, especially if "experts" have been "adjusting" the RF.

[Oren Grad]

If it does, simply reset the stops.

As implied by David's comments, if the GG is not properly adjusted, agreement between the GG and the infinity stops simply means that both are mis-adjusted, and on-film results will be off.

[Otto Seaman]

The Technika rangefinder should be scary accurate, spot on. What gets most people is the parallax error introduced when you rangefinder focus on something close by pointing the camera down, but are actually shooting straight and level. That can be a few inches right there and it is very easy to do without thinking or assuming it's a Leica that would not create as much of a difference.

What happens a lot of the time with otherwise mint cameras are home groundglass replacements and changing or loosing the shims/set screws, removing or adding fresnels, etc.

[Bob Salomon]

Are you using a cam that was cut to your specific lens? If so the cam is stamped with the serial number of the lens.

[dave_whatever]

The groundglass is correct by definition unless the camera has been damaged.

Or if the GG has been put in back to front, frosted side away from the lens for instance. That would give a uniform error across the range.

[Bob Salomon]

Or if the GG has been put in back to front, frosted side away from the lens for instance. That would give a uniform error across the range.

Or someone installed the Fresnel in front of the GG when the Gg was adjusted for the Fresnel to be behind it.

But the first question is about the correct cam.

[Leigh]

Or if the GG has been put in back to front, frosted side away from the lens for instance.
User screw-ups are included in the "damage" category. If the camera is not properly aligned, it's "damaged".

- Leigh

[Neal Chaves]

I had Technikas for years, a IV and a new Master in 1977, I used untill 1996. You will have to ask Bob Solomon for confirmation, but I don't agree that lens and cam compatability on the V and the Master was attained by adjusting screws on the ground glass of each individual camera. I feel it was attained by setting all cameras up to a standard cam in the redesigned RF mechanism which was then pinned in place.

The ground glass on any view camera back has to be accurately in place in the same position as the film in the holder once it is inserted. When a roll film back is used the same is true. What I suggested to the OP the same way I would proceed if I encountered a similar situation. Start with the basics when trouble-shooting, like first check the power cord. It may be, for instance, that someone swapped out one lens and cam for another of the same focal length without knowing that the infinity stops would need to be readjusted, even for two "identical" optics.

[David A. Goldfarb]

I have my Tech V sitting here in front of me.

Slip the groundglass panel off, and on the inside surface that holds the filmholder in place there are four tiny countersunk screws about an inch or so from the corners, each of which adjusts a small bar that the matte surface of the groundglass rests on. Adjustment of those four screws insures that the groundglass is in registry with the film plane and is parallel to the lens plane.

If you have an old camera that hasn't been for service in who knows how long, I'd have both the groundglass calibration and the rangefinder calibration checked before resetting the infinity stops.

[Otto Seaman]

And where in the USA would you do this? Nippon doesn't do cams (and was snotty-expensive) while the good service provider, Bob Watkins at Precision Camera Works, is training.

[David A. Goldfarb]

I don't suspect Precision Camera Works will be particularly cheap. They've serviced my Arca-Swiss B2, and the service charge was in line with the cost of the head.

When I first sent my Tech V to Marflex, I had two lenses cammed and the whole camera adjusted and one part and missing focus scales replaced, and I think it ran me around $1300. What's the point of owning such a precision camera, if it's not in perfect adjustment?

[Otto Seaman]

I don't begrudge Bob or the late Martin their fees at all, they are precision craftsmen of the highest order. Just pointing out that there is currently nobody in the USA qualified to adjust the Linhof cams, etc. I am sure that there are some other intelligent repair people who could set things right, but you'd want to make sure they know what they're doing. I don't have any idea what the alternatives are other than patience?

I do begrudge Nippon, who quoted me $900 for a new 45 Technika bellows and gave me a hard sell too boot. That's double what Marflex used to do them for. They lost my business for good.

[David A. Goldfarb]

Patience or sending it to the factory, I suppose. The Linhof website doesn't show any service shops in the Americas other than Nippon Photo Clinic.

[Bob Salomon]

Patience or sending it to the factory, I suppose. The Linhof website doesn't show any service shops in the Americas other than Nippon Photo Clinic.

Precision Camera will go to the factory in early Aug for factory training on camming. We will not open any further service centers in the USA.

[Mrsmartacus]

Dear All
Many thanks for all your contributions, it's really appreciated. I'll check through the advice and ensure that the cmaera is fully calibrated.

Andrew

[Jac@stafford.net]

A minor aside: One 'maybe' way to find if the infinity stop has been changed on your camera - locking it down should leave a dimple in the rail. If you find two dimples, then something has likely been changed.