I use a Canon PowerShot S100. My question is, why did I get this (for me) unexpected overexposure?
I was photo-documenting a project and wanted a close up with a good depth of field so I set
- Av mode f7.1
- auto ISO
- Compulsory flash mode
- Focus type - Macro/Close-Up
And got an overexposed result, the first picture.
Then I only changed Exposure mode from "Av" to "Program" and got a more reasonable exposure. Both pictures here are converted from CR2 to jpg without any enhancements in PhotoShop.
I compared EXIF data for the two exposures and found these differences and commons.
P Av
Easy shooting mode - Manual Manual
ISO Value - Auto Auto
Focus type - Close-Up Close-Up
Flash bias - 0 EV 0 EV
Auto ISO - 200 400
Base ISO - 200 200
FNumber - 2.00 7.10
ISOSpeedRatings - 640 1600
ExposureTime - 1/60 1/60
Exposure mode - Program Av-priority
ApertureValue - F 2.00 7.10
ExposureBiasValue - 0.00 0.00