Question for those familiar with Aperture and any of the PhotoShops ..... If I decide to edit the photo using photoshop, what happens to the original image when I end the photoshop editing (remove background, multiple layers for masking etc) and in what format are the results imported back into Aperture?
If you go the automated route and launch PS from within Aperture. Aperture makes a temp file with your image in it in PSD, TIFF or some other format. Inside PS you do "save" and PS overwrite the temp file and quites the Aperture grabs control of the file and saves it as a "version" of the image. Did I ge that right. You can customize the details to some extent too. The thing is that you don't see the image file unless you go looking.
iPhoto works about the same way. There is a preference called "external image editor". You tell it what program to use and iPhoto makes it mostly transparent. Aperture is about the same.