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08-30-2014, 01:28 PM   #1
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150mm showing wrong aperture in viewfinder

Hey guys,
I've just bought a Pentax 645N with a Pentax-A 150mm f/3.5 anda a Pentax-A 75mm f/2.8 LS. And for some reason whenever I use the 150mm and look through the prism the aperture doesn't match with the one in the lens. The only one that matches is 3.5, the rest are off by half a stop. Do any of you know what is going on?(the 75mm LS doesn´t have problems with this though)

08-30-2014, 04:26 PM   #2
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It could be a slight misalignment of the aperture lever, but it's more likely just rounding error. Your exposure should still be correct. If it bugs you should might just want to set it to "A" and use the e-dials to select the desired aperture.

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