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Bronica ETR Si matte screen misalignment
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PostPosted: Thu May 08, 2014 6:47 pm    Post subject: Bronica ETR Si matte screen misalignment Reply with quote

Hello everybody,

yesterday I received my Bronica ETR Si with two lenses. While shooting the first roll of film, I noticed that the focusing screen showed objects ~200 meters (~650ft) in focus even though I had set the lens to infinity. At first I thought it was a problem of the lens, but when I changed from the 75mm to the 50mm the problem persisted.
So I locked the shutter open and placed the ground glass where the film would be. Thankfully, the image looked focused there (so definitely not the lenses). When I put it back in, I noticed that the screen wiggled around a little. It seemed to be suspended from the two metal clips on the edges (one of those is loose). My guess is that these clips are holding the screen above the plane where it should be.

My alternative diagnosis would be that the mirror is misaligned, but because of the wiggling I'd say the fault really seems to be with the ground glass.

Is this fixable? How would I do this?

Thank you for your help.


PostPosted: Fri May 09, 2014 5:15 am    Post subject: Reply with quote

Common problem on many TLR and reflex cameras. Different cameras have different ways to adjust this, I don't know how its done with Bronicas.
The usual fixes are shims under the groundglass or adjusting the angle of the mirror.
If you have taken off the ground glass you may be able to see how it could be adjusted.


PostPosted: Fri May 09, 2014 10:24 am    Post subject: Reply with quote

There is a pair of screws on each side, maybe these move the ground glass up and down. I already tried to put two folded slips of paper beneath the focusing screen, this made the problem worse.

After looking at the construction of the area around the focusing screen I noticed a small recess on the front which looked like it was parallel to the pin on the front clip. As it turns out this is just the right size and position to hold the matte screen in place. No more wiggling and when the image is focused on the ground glass it's focused on the film plane.

Thank you for your suggestion.