Cropping Without Stretching the Face

Two photos can both be correct and be different shapes. The US wants a square; the UK, the Schengen countries and most of the world want a taller rectangle; Canada wants a taller one still.

That matters because the obvious way to move between them is the wrong way.

The shapes

Why stretching fails

Scaling a square image into a rectangle without cropping makes the face taller and narrower. It looks subtly wrong to a person and definitively wrong to a facial comparison system, which measures distances between features. Those distances no longer match your face.

This is worth stating plainly because image editors make it the default. Dragging a corner handle usually preserves the ratio; dragging an edge handle does not, and the result looks close enough that people submit it.

The rule is simple: crop to change shape, scale only to change size. Cropping discards pixels and keeps proportions. Scaling changes size and must keep the ratio identical.

Cropping correctly

Start from the largest original you have. Cropping throws pixels away, so a photo already cropped to one country's size has less to give when re-cropped to another.

1. Decide the target ratio from the table above.
2. Crop the original to that ratio, positioning the head so the chin-to-crown measurement lands in the required range.
3. Scale the crop to the required physical size at 300 DPI or better.

Head height is the constraint that decides where the crop sits, not centring. A crop that centres the face but puts the head at the wrong proportion of the frame is refused, and it is the most common fault in home-produced photos. Head height covers the ranges.

Why the head cannot simply be centred

Every specification leaves more space below the chin than above the crown, because the shoulders need to be visible. Centring the head vertically produces too much headroom and too little chest, which reads as wrong even before it is measured.

The rough rule is that the gap above the head should be around a third of the gap below the chin, though the exact figure varies by country. This is the part that is genuinely fiddly by hand and the reason the country pages position the crop for you.

Converting between countries

If you have a correct US photo and need a UK one, do not convert the print. Go back to the original photograph and crop again to 35 x 45. The US crop has already discarded the extra height a 35 x 45 photo needs, so anything derived from it will either be stretched or have the head at the wrong proportion.

Keeping the original at full resolution is the whole trick. Every specification can be produced from it, and none can be reliably produced from another specification's output.

Trimming a print

If you are cutting prints by hand rather than having them cut, the tolerance is tighter than it feels. A 35 x 45 mm photo trimmed to 34 x 44 is outside specification, and a millimetre is easy to lose to a wandering blade.

Cut against a steel rule with a sharp blade, and cut all the copies in one pass rather than one at a time. Scissors are the usual culprit: they follow the hand rather than the line, and the error accumulates along the cut.

Printing with a thin registration border and trimming to it is more accurate than trying to cut a borderless print to size by measurement, because you are following a printed line rather than a ruler held against paper.

Checking a crop before printing

Measure the digital file rather than the print. In any editor that shows dimensions, the ratio of width to height should match the table above to within a pixel or two, and the head should measure the required proportion of the total height.

Doing this before printing costs nothing. Discovering it after printing costs the paper and the trip.