I have followed a guide to generate gerber files in altium designer. This guide first goes to "File/Fabrication Outputs/Gerber Files" to generate gerbers and to open a CAMtastic file where you can see and edit them.
Until here everything is clear, but then the guide exports gerber files from CAMtastic to another folder, where gerbers are saved.
The thing is that some gerber files generated through the "Fabrication Outputs" option in the File menu have different size from the ones generated from CAMtastic throught the export command, although I didn't edit them at all in CAMtastic.
I am confused... why are they different? which ones should I use?