10-Dee-Q wrote in post #5534430
What is "Auto Lightig Optimizer" ?
It's similar to having the camera do an "auto levels" adjustment on the image. This helps give the "ready to print" results that people have come to expect from digicams.
What is "highlight Tone Priority" ?
HTP exposes the image at one ISO level below the indicated ISO level, thus increasing the amount of highlight headroom in Raw by one stop. The in-camera JPEG conversion then corrects for this, using a curve that gently compresses the extra highlights. Canon Raw converters presumably can do the same kind of correction—most third-party Raw converters don't and merely show the Raw file as being one stop underexposed.
can you please tell me when i should turn them on or off ?
They're options because some people like them one way and some like them another. If you're shooting Raw, you probably will want to leave them both off. If you're shooting JPEG, then it depends on what settings give you the results that you like.
i knew that we used to cover the vf when taking picture in bulb mode so thus the metering will be more accurate, but how about when taking pics with the liveview ?
do we still need to cover the vf ?
No, you don't need to. The reason that you cover the viewfinder in Bulb mode is to prevent stray light coming in the viewfinder opening from fooling the metering sensors in the viewfinder. Those metering sensors are not used in Live View mode, and the mirrors are up and blocking any light coming in the viewfinder from reaching the main sensor.