vignetting of 75 mm lens on Linhof Master Technika

[Henry Carter]

When range-finder focusing a 75 mm lens (in my case a 75 mm Grandagon N) on the Master Technika the edge of the camera bed intrudes into the 4X5" negative. Linhof recommends using slight lens rise to correct this, as stated on page 15 of the current instruction manual:

"Please note:
The combination of 75 mm wide -angle lenses and 4x5" film may cause slight vignetting even with the groundglass in horizontal position. For range-finder focusing with 75 mm lenses, a slight lens rise is therefore recommended."

Does anyone have any experience using lens rise when range-finder focusing the Technika, and if so, what is the optimum amount of rise? I was thinking of starting with about 3 to 4 mm of lens rise as I'm not sure how much "slight" translates to.

Regards,

[Jay Lnch]

Henry, did you try dropping the bed at the same time?

[tor kviljo]

I have never had the Master Technika, but I have used several earlier ones, super-technika 6x9, technika III & IV and 70. On all these, use of supervide lenses required that the bed were dropped (to only the first click on IV's and the other with several positions drop-bed if I recall right) , repositioning the front standard with backward tilt + rise. This were necessary to get lower part of focussing bed out of field of view + being able to push focussing track in to main camera body for focussing at infinity. I belive the drop bed-first position & max. backward tilt exactly contradicted each other, making it easy to zero the camera in vide-angle mode.

[Henry Carter]

In a 4X5 Master Technika you cannot drop the bed when range-finder focusing because of the lens cam in use. If you were not using the range-finder, and hence no cam, then of course you could drop the bed. The above quote is from the instruction manual for the camera, and the recommended solution is to use "slight" lens rise when range-finder focusing with a 75 mm lens.

All that I am specifically asking is how much lens rise have experienced users found to be optimal when range-finder focusing with a 75 mm lens on a Master Technika?

[David A. Goldfarb]

My 75mm lens isn't cammed for my Tech V, but I think you're going to need to determine this for yourself, because it will depend on whether someone else has the same lens on the same lensboard with the same amount of shimming and the infinity stop in the same place. What I would do is focus the lens at infinity, check the groundglass, and raise the lens the appropriate amount. If you want to be able to do it quickly on the fly, then mark the position in a way that's easily readable (say by drawing a line or a dot on the front standard and/or lensboard frame).

[David A. Goldfarb]

And as an afterthought, you might want to mark two positions--one for horizontals and one for verticals.

[KenM]

With my Grandagon-N 75mm on my MT, I need to use 1 crank of rise when the back is horizontal, and about 4 1/5 cranks when vertical. With this lens you don't have to drop the bed, which is nice since you can focus using the standard focusing controls. You just slide the bed back all the way, and slide the lens just onto the track and focus away...

[martin_4668]

Hi Henry

"1 crank" ...is that part of the metric vs inch dispute on this site ??? I like it though. I am sure just 3-4 millimeter should do it. Shoot a few tests - that my recomments.
I am still waiting for my tech V + 75/4,5 from camming at Linhof germany. It has been there for 7 month now....I am not kidding !! If I wasn´t so good friends with them, I would a bit disappointed....
Even though....you know that a Technar + 75 would be the appropriate solution for you...:-) or my Alpa + Apo-helvetar 48

[Henry Carter]

Thank-you all for your helpful replies.

One crank of the rise lever resuts in about 3 to 4 mm of lens rise, and so this is what I used when shooting yesterday. Using one crank is also easy to remember and repeat. I await the results...

Martin, it sounds like you should send your Technika and 75 mm lens to Marflex in New Jersey for camming. They are the US service centre for Linhof and likely are the best place in the world for Linhof repairs and servicing. Waiting seven months to have a lens cammed is not acceptable, so you should perhaps insist that Linhof send your camera directly to Marflex as a consequence.

I have long lusted for a Technar for wide angle hand held shooting, with either a 75 mm (or even better) a 65 mm Grandagon N. The ALPA with 48 mm Apo-Helvetar would be an excellent 6X9 alternative.

Skaal!

[David A. Goldfarb]

I've been waiting about that long for a set of fresnel clips from Marflex, and I've heard other reports of long waits. I think their turnaround times depend significantly on the parts they have in stock from Germany.