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04-07-2009, 11:39 PM   #16
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QuoteOriginally posted by Marc Sabatella Quote
There's several things that could be going on here, most of which have already been touched on, but at least couple that haven't, and they are worth listing explicitly. Here are the ones I haven't seen others mention:

- With manual exposure lenses, multi-segment ("matrix") metering is not available - the camera will switch to center-weighted mode. That will create differences in exposure from what you might be used to, and since center-weighted mode cannot protect highlights like multi-segment can, it often leads to overexposure compared to muliti-segment.

- The lens could be defective - the aperture blades might not be closign quickly enough, causing the aperture to be larger when the pciture is taken than it should be.

Here is my restatement of the possibilities that have already been raised:

- It could be a combination of high ISO and large aperture that is causing the camera to need a faster shutter speed than it can actually. If the camera is reporting 1/4000" shutter speed, chances are good that it wishes it could gone faster. Reducing ISO or stopping down would allow the camera to shoot with.

- The K10D and K20D do have a specific issue related partly/mostly to the focus screen that causes poor exposure with manual exposure lenses, especially when stopped down.
The lens is a manual focus TOU FIVE STAR 500mm f/8. This is a very long, but THIN telephoto. I used the green button to meter the shot, and it exposed very brightly. I would manually increase the shutter speed to about two stops to get a desired result.

04-07-2009, 11:41 PM   #17
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QuoteOriginally posted by xjjohnno Quote
I've found that more of an issue with some lenses and not others. Some meter fine while others over expose so I won't go blaming the exposure metering so much as how it works with some lenses. And it's consistent with those lenses.
What kind of lenses?

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