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08-24-2010, 08:08 AM   #1
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(m42)Carl Zeiss Aus Jena metering problem

My new tessar 50mm 2.8 came in today. Its my first screwmount lens. I set my aperture manually, but when I take a picture, the blades dont move.

When I push the preview aperture button on the lens the aperture works, and I can meter and take pictures that way as long as I hold down the button.

Moving the off/on button to aperture preview doesnt work.

my question is how do I take pictures without holding the aperture preview on the lens?

08-24-2010, 08:27 AM - 1 Like   #2
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Unless you're using a screwmount era film camera, the aperture blades are not going to move when you take a photo. Not on your DSLR at least.

My guess is that you need to modify the aperture activation pin in the back so that it is constantly depressed even in the manual mode. You need to open it up from the back, and use either a piece of aluminium foil shaped into a tube like bit, a section of ball point pen (the inside thin plastic piece that holds the ink) or a section of a q tip. Forum member Melissa has a great tutorial on fixing it with a q tip piece. You should PM her. Unfortunately, her tutorial is for a Helios but the design should be similar.

Honestly, I wouldn't bother fixing that. I love pressing the aperture button on the lens to take a photo at a previously dialed down aperture. This lets me switch from f2.8 to f8 with a quick touch of the button. You'll find yourself taking photos faster with it.
08-24-2010, 09:27 AM   #3
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Original Poster
thanks for the help!

I'm going to keep it the way it is.
08-25-2010, 10:50 AM   #4
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Note that most screw-mount lenses (including Zeiss ones) have an auto/manual slider. When using it on a DSLR, you have the slider in the manual setting, then the aperture closes and opens as you move the ring. The downside is that the viewfinder dims as you stop it down, but it allows you to shoot in Av mode without worrying (too much) about metering.


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