Photoshop's main tool bar
Adobe's Photoshop and Apple's Aperture are similar in that they both have digital image-editing capabilities. However, Photoshop is explicitly designed for performing detailed edits. As such, it offers more image-editing options than Aperture. In contrast, Aperture's purpose is to organize images, speed up work flow and make it easy to find desired files. Thus, Photoshop and Aperture are not competitors as much as they are complimentary tools for different stages in the image-editing process.
Aperture Features
Aperture allows users to edit the metadata of their images. This means that you can use the program to input information about each photo such as where a picture was taken, with what camera and for which client. The program then allows you to organize your images into groups based on this information. In addition the program allows you to perform global edits. This means that you can apply an edit to a group of images all at once. While these edits are not as involved as edits in Photoshop, they serve as a time-saver for photographers who need to apply only a few minor changes to large amounts of files.
Photoshop Features
One of the primary advantages of Photoshop is its ability to support multiple layers within a given file. This is key to the program's ability to perform complex edits. Using this feature, users can place different elements that make up an image on different layers. They can then apply certain edits to certain layers while leaving others untouched. Photoshop also allows users to place masks on its layers. A mask is content that sits on top of a layer's main content. This allows users hide a part of a given layer and to blend the layer's content with the mask's content.
Limitations
Aperture is limited in that it lacks most of the editing options present in Photoshop, layers and masks being two of the most powerful and widely used. However, unlike Aperture, Photoshop doesn't provide users the same global view of their files. That is, Aperture can display previews of many files at once and allow users to edit files without having to open them. Photoshop doesn't have this ability.
Considerations
When you make an edit in Aperture, the edit only applies to the file while it is open in Aperture or once you import it into another program. The original file remains the same. In contrast, if you edit an image in Photoshop, it applies to the original. This can pose a problem if you make an error then save a file that you do not have backed up.
