cameracropioszoom
iOS devices with cameras allow the user to "zoom" into the image being captured. This does not move any lenses or anything; it is a digital zoom and is conceptually equivalent to cropping in post.
However, I would like to know if there is any (however small) difference in output between an image that is captured while zoomed in and one that is only cropped after the fact.
But of course Preview!
To resize: Choose Tools > Adjust Size, then enter the size you want to change the image to, then click OK
To crop: Click the "Select", then click and drag to select the area of the image that you want to retain. Next, choose Tools > Crop or press Command-K. If you crop too much, you can press Command-Z or choose Edit > Undo to undo the crop.
Mystery solved! Behold the following two screenshots. The first is from Camera 1:
and the second from Camera 2:
See the difference? One of the cameras had a DCIM folder as a top-level directory (created, I can only assume, when I used that camera once to take a still photo) and the other did not. Apparently the presence of that folder is what caused the OS to recognize it as a "device".
I just used Camera 2 to take a single photo, then connected it to my Mac. It now has a DCIM folder, and iPhoto launched immediately. That appears to have been it.
Best Answer
In digital zoom, the camera scales up the pixels to give out the photo with the same resolution as with no digital zoom photo. In cropping, the cropped photo has lower resolution compared to the uncrossed photo.
So I can say that digital zoom is conceptually equal to cropping and then scaling the cropped photo back to its original resolution. The output photos would be the same if the scaling algorithms used in digital zoom and in post scaling are the same.