Photoshop on the Mac is the same as Photoshop on windows... with the exception that just about any time you're supposed to hold CTRL + any other key... on a Mac you hold COMMAND + that same key.
I use Aperture -- which is $79 on the App Store. Aperture and Lightroom are _very_ similar in terms of functionality.
Apple originally created Aperture because Photoshop isn't actually intended as a tool for photographers... it was a tool intended for publishers. Apple wanted to get rid of a lot of the complexity and create a program that, for the most part, does what you would have traditionally done in a darkroom with the goal of also
(a) managing massive numbers of images -- it's a digital asset management app and is designed so that even if you shoot heavily and all the images you have cannot be stored on the hard drive because there's just too many... Aperture can manage offline images (stored on external drives) and can also support multiple libraries (but creating multiple libraries usually isn't necessary.)
(b) it's optimized for "adjustment" (the sorts of things you'd do in a darkroom) and not designed for wholesale edits. Whereas Photoshop will allow you to do things to a photo that don't represent reality (e.g. adding things to an image that weren't really there or distorting the image beyond anything possible in reality, etc.) Aperture (and Lightroom) allow you to apply "adjustments" such as exposure, shadows & highlights, color, noise, sharpening, curves & levels, etc. It does do blemish fixing and has simple edit tools such as cloning. Just about any adjustment that could be applied to a "whole" image can also be "brushed on" (or you can pply it to a whole image and "brush away" what you don't want) to create localized adjustments. ALSO... you can apply changes to one image and copy those adjustments to a whole set of images instantly because you don't open files "one at a time" like you do in Photoshop. You can also have plug-ins. As the tool is not intended to replace Photoshop, you'd still need a tool like Photoshop (which is the SAME Photoshop on a Mac as on Windows -- no differences there) for more aggressive editing.
(c) it's designed for a RAW workflow and it's non-destructive. You can edit JPEGs, but since JPEG is more of a final output format and RAW provides better adjustment latitude, the tools are optimized for RAW. To save space, everything you do to an image is not technically applied to a real physical image. It's merely recorded as meta-data. It knows how much you moved each adjustment and if you applied an adjustment in a localized area it records where the adjustment was applied. But this just builds a list of changes you've made. When you open an image, it opens the original... and then applies all those changes again instantly to render the "version" of the image as you left it the last time. You can actually turn any adjustment on or off at any time (if you don't like how you applied one adjustment, you do not have to clear the image back to the original and start over.) You NEVER lose the original data.
Nearly (but not quite) everything I need to do to an image I will do in Aperture. It's very rare that I actually have to invoke Photoshop (which, btw, you can do directly from Aperture -- I just right-click on the image, pick "Edit in Photoshop" and it creates a duplicate (so as to not lose the current version) in which it applies all adjustments and then sends that image to Photoshop. When you quit Photoshop it saves directly back into the Aperture library again.
The difference is... it's much much faster to edit lots of images in Aperture than it is in Photoshop.
Adobe... seeing this as a very real threat, then created Lightroom to prevent the mass exodus. Since Apple created Aperture, it's only available for the Mac. This was a huge benefit to Adobe because Lightroom runs on both Mac and Windows. Lightroom is essentially designed to go toe-to-toe with Aperture (and it does this extremely well). But because you can get Lightroom on either platform, Lightroom is more popular. The downside to Lightroom is that it's made by Adobe... which means that like everything else Adobe makes, they sell it for far more than anything similar to it.
But there's _very_ little that you can do in Aperture that you can't do in Lightroom and vice versa. Neither is "substantially" better than the other since they were basically both designed to do the same things. As such, I like Apple's licensing and pricing better... which is that you buy it once on the App Store and it's licensed to every computer you own and this license is substantially less than what you'd pay for LIghtroom (especially if you own several computers.)
Tim Campbell
5D III, 5D IV, 60Da
