What's the difference between the 4D size and 4R size of digital photos?

1, digital photos of different specifications:

4R Size: A photo with the aspect ratio of 3 (height): 2 (width). The actual print size of 4R is10.3cmx15.2cm. ..

4D size: the photo with the aspect ratio of 4 (height): 3 (width), and the actual size printed in 4D is15.2cm×11.4cm. ..

2, the photo size is different:

4R size: the actual size is 6 inches *4 inches, that is,10.2cm×15.2cm. ..

4D size: the actual size is 6 inches× 4.5 inches, that is,11.4cm×15.2cm. ..

Extended data:

The size of photos is usually in inches, 1 inch ≈2.54 cm. An x-inch photo means that the long side of the photo is x-inch. For example, the length of a 5-inch photo is 2.54x5 =12.7cm; The length of 12 inch photo is 2.54x12 = 30.5cm. ..

ID card, physical examination form, etc. Most of them are one inch smaller than 22×32mm, the photo size of the second-generation ID card is 26mm×32mm, the ordinary one-inch photo is 25m× 35mm, and the photo size of China passport/travel permit is 48mm×33mm, in which the head width is 15mm ~ 22mm and the head length is 28mm ~ 33mm.

Baidu encyclopedia-photo size