I'm getting my passport renewed, but why should I pay for a simple instant photo when I can take my own with a better quality camera?
It is easy to take a digial photo and to crop and scale it to the right size. The application form says the photos must be 45mm high and 35mm wide, and the head between 32-36mm tall. Printing to a 4x6 inch photo at 300dpi requires an image that is 1200x1800 pixels in size. The passport photos will be 540 pixels high and 420 pixels wide--you can get eight photos onto one print. The head will have to be between 384 and 432 pixels tall. That was simple mathematics.
The difficult part was the things that they don't tell you:
So I had to do it three times before I got it right!
They are very particular about the size of the face. If you are doing it, I suggest including some 10% larger and 10% smaller pictures on the print.
Still, doing it this way I have a much nicer looking photo and paid a small fraction of the price for it... just don't count the time and effort it took!