You have a photograph you like. Can it become a passport photo? The honest answer is that it depends on how it was taken, and you can tell before you try.
1. Was the camera far enough away?
This is the one people never check and the one that cannot be fixed. A photo taken at arm's length has the wrong facial proportions - the nose rendered large, the ears small - and cropping does not change proportions.
A photo taken from a metre and a half or more is fine. A selfie is not, however good it looks.
2. Is there enough resolution left after the crop?
This one is arithmetic. A passport crop keeps the head and a little shoulder, so the final image is a small part of the original frame.
You need the crop to be at least the required pixel size - typically 413 by 531 for a 35 by 45 mm print at 300 DPI, or 600 by 600 for a US square. If the face occupies a quarter of the frame in a 12-megapixel photo, the crop lands around 1000 pixels tall, which is comfortable. If the person is a small figure in a landscape, it will not.
Enlarging to reach the number does not help. It produces the dimensions without the detail, and sharpness checks notice.
3. What is the background?
Replacement handles colour and objects. It does not handle a shadow across the face, hair merged into a dark background, or a busy pattern directly behind the head that leaves the segmentation ambiguous.
A plain wall, a clear sky or an evenly lit surface behind the head all work. A bookshelf usually does not.
4. What else is in the frame - and on the face?
Another person's shoulder at the edge of the crop, a hand, sunglasses, a hat, a wide smile, a head turned three-quarters, eyes looking away. All are refusals, and none is fixable by cropping.
This is where holiday photos usually fail. They are taken outdoors in sunshine, which means squinting, hard shadows and often a hat.
The quick test
- Was it taken from more than a metre and a half away?
- Is the face looking straight at the camera, neutral, eyes open, no glasses?
- Is the background behind the head plain and evenly lit?
- Does the head fill enough of the frame that a passport crop still has the pixels?
Four yeses and it is worth trying. One no and a new photo is faster than the argument.
Crop from the original, always
One practical rule. If you need the same photograph for two documents - a passport and a square visa upload, say - crop each one from the original, not from the first crop. Re-cropping a crop puts the head and eye line in positions that were correct for the old frame and wrong for the new one, and it throws away pixels twice.
IDShot works from the original photo each time, so switching a picture from one document preset to another re-crops from the full image rather than from the previous export.