Photons Missing In Action

Started Nov 24, 2009 | Discussions thread
atigun Contributing Member • Posts: 771
Re: Part 2: Aperture Control Accuracy

Should not the exposure be correct wide open, since that is where the light is metered? (If not, the body's metering could as well be involved). So when you write "Overexposes about 1/2 stop through entire range" do you mean all apertures except wide open?

I wonder ho much light falloff towards the edges wide open influences metering in different modes. Here is a visual example I performed a while ago with my D200, if possible with aperture controlled both from the lens and the camera. It needs updating as I have repeated it later with different bodies and more lenses, but not had time to put it together:
Some more info here:
http://otoien.zenfolio.com/p626313451/eac136c2

At 24mm my 12-24 only stopped down 1/3 stop at f/5.6 (overexpose +0.7 compared to wide open) and is going back to Nikon for adjustment/repair. In search for a correctly centered copy of this lens, I encountered several copies showing the same pattern if not quite as bad.

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Atigun valley, a place north in Alaska

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