Am I not able to add layers (adjustment layers) when working with a TIFF file? I have converted some RAW files to TIFF, then when I go to open them, ALL of the options under the Layers menu tab are darkened... I can't do anything.
Is this normal? Do I have to save it as JPEG before this?
With TIFF files, I need to convert them into 8-bit from 16-bit before I can photoshop them. Is there no way to retain the 16-bit depth while working in photoshop?
When you are WORKING WITH files, save them in "native" Photoshop format, which should support all of the features. When you are DONE, save a copy as a TIFF, flattening the layers.
TIFF is a format designed to be placed into other documents and printed, not particularly for editing.