D200 Exposure Off in Shutter and Aperture Priority

[jhelms]

Something I have noticed lately, when using shutter priority or aperture priority on my D200, the camera seems to allow quite a bit of under and overexposure that you'd think could have been corrected by it changing the f-stop (or shutter) more aggressively.
For instance, recently I took some outdoor pics of some birds and I experimented with some fast shutter speeds. At iso400 and 1/1000 shutter speed (using shutter priority - and "isoauto" was off) the camera allowed an unusable amount of underexposure, while keeping the f-stop around 5.6-7.1 range. I kept thinking it would open up the f stop to more properly expose those.

Then in apeture priority on another set of test pics, I had some pics really blown out with the f stop opened all the way up to 3.5 on the 18-200VR lens. The shutter speed was hanging around 1/400th to 1/500th or so, plenty of room to speed it up to correct the overexposure, right?

I was hoping the camera would take more of an active role in those two modes to get the exposure correct, otherwise I might as well be shooting manual. Or maybe testing exposure in P/auto and then adjusting off that in manual mode.

[angevin1]

Both of these scenarios describe the same prob, right? Both are based on the camera deciding exposure adjustments necessary. So a reasonable guess is that the cam sees something you do not intend for it to see to make its decision. Which is why when I shoot in those modes I often have to point my lens away to a darker/lighter place to ensure I get correct exposure for the item i want exposed properly....this being w/o flash of course.

cheers, tom

[jhelms]

Both of these scenarios describe the same prob, right? Both are based on the camera deciding exposure adjustments necessary. So a reasonable guess is that the cam sees something you do not intend for it to see to make its decision. Which is why when I shoot in those modes I often have to point my lens away to a darker/lighter place to ensure I get correct exposure for the item i want exposed properly....this being w/o flash of course.

cheers, tom

Part of my confusion is that in P or auto mode, the exposures are fine, it's only wacky when in A or S modes.