This is really just a sanity check!
Background: The current standard Pi Rasbian image is 3.8GB in size. If I write that to (say) an 8GB card it'll only give me access to that 3.8Gb until I resize the partition (for which Raspbian includes scripts).
Assume I *don't* do that resize.
I set things up the way I want on the Pi, and I then want to create a new image of the SD card to restore to another card (possibly a different size). "dd" will get me an 8GB image by default (since it's an 8GB card) but am I correct that I can safely limit the image to the exact size of the original Rasbian image?
The objective here is that (a) writing a 3.8GB image to a new card is much faster than writing an 8GB image, and (b) that it will safely write to any 4GB/8GB/16GB/etc card (where an 8GB image might not fit on a different model of 8GB card). The third benefit (c) of a smaller image is less of a concern as I can compress it anyway and unused space should pretty much disappear that way.