Master Technika why the shims beneath the ground glass?

[Jordan]

So why did Linhof complicate things by having the ground glass need shims for focus alignment? Why wouldn't a ledge on the frame suffice? I would like to maybe add a brighter screen and know if my alignment is correct without the need to send it away to the service place. I've changed out my ground glass on other cameras plenty without ever having to consider this. Linhof clearly makes a beautiful camera, but a bit particular.

[Brian Ellis]

I don't know why they didn't design the camera differently than they did. But when I replaced the original screen on a Master Technika with a Maxwell screen Maxwell sent replacement shims to ensure a correct fit with the new screen. And when I replaced the original screen on a Tech V with a BosScreen the new screen was designed to use the existing shims. The only time I would think you'd have a problem is if you just buy a generic screen without getting either new shims for the new screen like Maxwell or a screen made for your model camera like BosScreen and I don't think I'd want to use a screen made by someone who didn't do one or the other.

[Jack Dahlgren]

shims generally allow adjustment if needed. So if the back is too far away they could use a different thickness of shim rather than thinning the back. Shims are kind of old-school.

[William Whitaker]

Sticking my neck out on this one, but Technikas are/were designed to use cammed lenses as well. The shims may possibly be so the ground glass focus can be matched to the cam focus.

[Peter K]

Sticking my neck out on this one, but Technikas are/were designed to use cammed lenses as well. The shims may possibly be so the ground glass focus can be matched to the cam focus.

A shim between shutter and lensboard does this job better. But the gg should be aligned so the focus plane is the same as the film surface.

[Frank Petronio]

They standardized the cams from the V onwards, so once the cams were a fixed item I guess they needed a way to adjust the ground glass.

Seeing there have been so many different fresnel options, it's one of those things you'd always want to check with a used Technika. Since they are valuable cameras, letting Marflex give it a look over always seemed worth the cost. Martin is very honest and straight-forward.

Since I don't like fresnels or trust (my use of) large-format rangefinders, I prefer the way Sinar does their back - you can slip any old glass on top of a referenced surface. Use an external fresnel if you like, but don't leave the thing mounted to your camera to muck things up and get in the way of actually seeing the image.

Or on my Crown you simply never mess with it, something breaks you just get another $200 camera lol.

Wista, Arca, the Chinese, all tie you into their fresnel choices unless you want to monkey around retrofitting a Maxwell or something else, and then you still need to check distances and test, so the Linhof isn't any worse in that regard. I bet a lot of people have slightly off distances but because they stop down to >f/16 they never notice.

[Bob Salomon]

Unless you have a Boss screen where the image forming plane is between two sheets of glass or have some other exotic screen where the imaging forming plane is not on the front facing surface then you have no worry about the shims.

The ground side of the gg faces the lens and is placed directly onto the shims. The thickness is immaterial as the critical surface is on the shims.

So there is no need to send your camera out to change the gg since adjusting the shims is not necessary to change the focusing screen. Unless someone was tampering with the back.

So just like Frank's camera, you can put any gg on the shims and the gg will be in the proper location. In other words, the shims were set at the factory to the proper distance and the user should have no reason to set them any differently. They are what assure not only proper focus on the film when using the gg but also with the rangefinder when you use that as well.

Why the shims? Some people have multiple Technika cameras so from the V on all Technika 45 cameras had a zeroed gg. This was done by adjusting the shim settings on all V and Master Technika Classic models so they can share the same cam if that cam's lens was used on another body.

[Neal Chaves]

There's a bit more to it than that. Every late Tecknika camera has the focusing track set up on a "hard stop" so that the combination of the view on the shimmed ground glass and the "infinity" position of the focus track and RF match up with the film plane. This is unlike the Crown and Speed Graphics which can be cammed and set up on "hard stops" but come from the factory with cams that often set up on "soft stops". If unqualified wingnuts have messed with either camera, all bets for accurate focus either on GG or by RF are off.

[Bob Salomon]

There's a bit more to it than that. Every late Tecknika camera has the focusing track set up on a "hard stop" so that the combination of the view on the shimmed ground glass and the "infinity" position of the focus track and RF match up with the film plane. This is unlike the Crown and Speed Graphics which can be cammed and set up on "hard stops" but come from the factory with cams that often set up on "soft stops". If unqualified wingnuts have messed with either camera, all bets for accurate focus either on GG or by RF are off.

Neal,

The Technika IV and later cameras accommodate a series of Folding Infinity Stops. One for each lens cammed. These, as well as the focusing scale for each lens, are installed at the time the lens is cammed. A Master Technika is only shipped from the factory with a Folding Infinity Stop installed if the lens was ordered for the camera at the same time as the camera. If the lens is ordered after buying the camera then the stop is installed either by the Linhof service center in your country or by the user in conjuction with an installation kit that includes a target that you have to place on a window.

[Neal Chaves]

No, those are bed stops for the lenses on the camera bed. There are hard stops for the focus track located at the front bottom of the track. They were adjusted for the standard spec for infinity and then pinned there. These stops come to bear on the front cover casting. Don't ever take those stops off (They are pinned on!) if you don't understand the mechanism.