Originally posted by vanyagor Can you explain what a correctly exposed image means in this case.
Not in just a sentence or two. But any number of books on the subject will. The short version is just what I already said: any simple subject should be rendered with 12-13% reflectance what this actually means in practice is the tricky part. at least, that's correct from the camera's perspective. Whether or not it happens to meet your persoanl expectation for that particular scene is another matter.
Quote: I thought that a correctly exposed image is when the whole histogram is within the range
that's not even always possible. Depending on the metering mode you use and the scene, it's entirely oossible a correct exposure will clip at one end or the other.
Quote: In fact one has to look at color histogram too, not just the luminance histogram. Is that correct?
one desn't "have" to do any suchthing. Regarldes of what is techically correct from the standpoint of metering standards, what matters is how like the image itself.
Quote: Can you explain why wrong exposure wide open implies that it is camera's fault?
Because the camera meters with the lens wide open. It measures the actual amount of lens reaching the sensor, not the amount that would reach the sensor if the lens were stoppsed down.
Quote: Could it be that the aperture just doesn't open fully for whatever reason
if that were happening, then the camera would be metering that way, too. So the exposure should still match the shot.