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12-05-2011, 09:50 PM   #1
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Zeiss Flektogon f/2.8 Zebra Problem?

Hello, I'm pretty new to photography. I've recently purchased a Carl Zeiss Jena Flektogon f/2.8 lens, the Zebra kind. I'll try to explain the problem (and I'm not even sure if there is one), as best as I can:

Let's start with the f-stop ring set at f/2.8 and the focus ring set at infinity. Now I begin to turn the focus ring clockwise, getting closer to the shortest distance of 0.18m. As the focus ring passes the 0.3m mark, it begins to turn the f-stop ring counterclockwise. Ever so slightly. By the time the focus ring is at 0.18m, the f-stop ring has turned to position f/4.

What's more strange is that the aperture blades are still in the fully open position (f/2.8). Now I turn the focus ring counterclockwise, back to the infinity position. The f-stop ring remains at the f/4 position, but the opening between the aperture blades gets smaller and smaller until it corresponds to the f/4 position at the moment the focus ring reaches infinity.

Is this how this lens is suppose to work, or does it need adjusting? Any help would be greatly appreciated.

12-05-2011, 10:50 PM   #2
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It does this while mounted to the camera? Or when you're holding it in your hand?
12-05-2011, 10:54 PM   #3
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It does that regardless if it's mounted on the camera, or in my hand.
12-08-2011, 04:59 AM   #4
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without seeing the lens and knowing exactly the focal length, it soundsas though it is setting the aperture ring to the effective aperture when close focusing, this is important especially for flash, so you know the real maximum aperture at close focus distances.

it sounds as though there is no means to go back the other way, i.e. focusing out from minimum to infinity, to retain the maximum setting.,

this may be normal.

.18 meters is awfully close to the subject

08-06-2015, 02:49 AM   #5
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My Flektogon zebra does the same.

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aperture, blades, f-stop, f/2.8, f/4, focus, infinity, pentax help, position
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