Whenever an astronomer takes a picture of an object in the sky, they usually want to analyze either the color of the image or the amount of light being produced and then recorded in the image. In both cases photometry is the tool an astronomer will use when this analysis is necessary.

Below are listed links to other internet pages that can help. Choose the link to the specific interface you are using.

All are free programs. (Subaru Makalii will need some correspondence in one month to work again.)

Aperture Photometry Tool (This program works on Macs and PC's)

Salsa J (This program works on Macs and PC's)

Subaru Makalii (This program works on PC's only)

DS9 (this also only explains color imaging)