CCD Images in Photoshop 5 What format Fitts/Tiff ?

CCD Images in Photoshop 5 on a MAC

I would like to post process my images on my MAC with photoshop 5. What format is best on a MAC?
Fitts or TIff or other?

What software do I need on a MAC to view these files in photoshop 5?

I share Fitts file from my observatory PC with my MAC but a can not open them in the MAC. What software do I need? Thanks Craig

I would suggest Tiff, fits requires "Fitts Liberator" to import Fitts files and properly work with them. Most everyone that I know stacks and preprocesses subs and then coverts the master stacks to TIFF or combines them and exports the RGB in TIFF and Luminance separately in TIFF and combines the Lum with the RGB in Photoshop.