问题
Is there any way to get the exposure settings (aperture, shutter speed, ISO) for a photo taken on an iPhone?
An app running on the iPhone can use the UIImagePickerController interface for taking pictures, but that doesn't provide much info about the picture.
The EXIF data for a photo taken on the iPhone contains aperture info, but not shutter speed or ISO.
回答1:
This is not currently possible using the SDK. If it's something you think is needed, I suggest you file an enhancement request with Apple.
回答2:
Update, so people coming here would know:
In iOS 4 you can set exposure/white balance/focus to some extent. Basically you can control the mode (auto/continuous/fixed) and the point of interest for these parameters.
Regardless, if you are capturing still images - you can extract metadata from the image's exif information (actual exposure, shutter speed, iso, etc.)
HTH someone, Oded
来源：https://stackoverflow.com/questions/373357/obtaining-iphone-photo-exposure-information