I surf the web and do some light photo editing
The MacBook Air will do these tasks easily enough, as long as you don't start creating 4 GB HDR images in Photoshop. All in all, this is the type of user that the MacBook Air was made for.
I'm a serious photographer and will edit my photos in Photoshop
Even with the souped-up 13.3-inch MacBook Pro, you'll encounter problems using the MacBook Air. Since this version of the MacBook Air (13.3-inch, 4GB of RAM, 256 GB hard drive) costs as much as a MacBook Pro 15, the MacBook Pro 13 or 15 are much better choices for this.
I do some video editing
The processors on both MacBook Air models are slow when compared to the ones available on the MacBook Pro and other laptops. If you do quite a bit of video editing, then you should opt for another laptop.
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