Maintaining Aspect Ratio while Image Cropping using Preview I like the convenience of being able to crop jpg/png images with Preview, but I would also like to be able occasionally to restrict the aspect ratio of the cropped image. This is useful, for instance, if I want to prepare images for printing in 4x6 or 5x7, while avoiding any surprise cropping made by the photo lab.

I am hoping there is a quick and easy way to do this (i.e., without needing to invoke the behemoth of image editing for this elementary task). Are you aware of one?
In Photo (not iPhoto) click Edit



then Crop



then Aspect, and finally Original

.

As of this writing (August 2016), there is no way to do this using Preview or any other stock program in El Capitan. Photo is nearly stock though, and it's easy enough using Photo.