exposure help

[TeeZeeMee]

i lately have been shooting with my D90 during the day and most of my shots are overexposed according to the after shot histogram.
i normally use Aperature priority and wonder what it is that im doing wrong? I normally shoot at 200-400 iso during the day with strong sunshine and whatever shutter speed the camera sets.
should i just start going fully manual to get better exposures? I shot tonight in shutter speed priority and i seemed to be able to dial in the exposure better

i have read up a bunch on the triangle and understand how each plays their own role, i will be practicing a lot more for sure. just wondering if i may be overlooking something?

 

[KmH]

What do the histograms look like?

If there is a lot of bright sky or other highlights in a scene, a histogram will show quite a few pixels to the right side of the histogram.

Some types of highlights need to be over exposed.

The way digital images work, most of the time you want to ETTR, Expose To The Right side of the histogram, particularly with a scene-referred image.

That is because fully 1/2 of all the image data is in the brightest stop of exposure, and each dimmer stop of exposure only has 1/2 of what was left. http://www.adobe.com/digitalimag/pdfs/linear_gamma.pdf

http://wwwimages.adobe.com/www.adob...ly/prophotographer/pdfs/pscs3_renderprint.pdf

 

[TCampbell]

Any distribution of the histogram can be a good exposure as long as the graph isn't "climbing the walls" on the left or right. As you learn about the histogram, there can be a tendency to believe the bulk of the graph should be in the middle -- but this completely depends on the exposure (and frankly if it were all in the middle the photo would usually look dull.)

Photos that are intended to be dominated by darks will have the bulk of the data to the left. Photos that have a lot of brights & whites will have the bulk of the data to the right. That's not an indicator of an over-exposed or underexposed shot as long as it isn't so far the right (or left) that some data is jammed against the wall.

 

[Ysarex]

Show us photos.

TC -- if the histogram graph climbs the wall on the right side relative to what should have been difuse highlights that = overexposure = failure. However some left side wall climbing is often very appropriate. In high contrast lighting conditions it is expected that some degree of shadow detail will fall into black.

Joe