[Tatiana]

In Photoshop, pictures with 72 dpi display full size(at 100%) when I go to view > print size. But pictures with 300dpi display at 24%. Why is this, I thought the higher the resolution the better, and the bigger it should print.

[Tatiana]

A little update...it's not just that 72 dpi displays at 100% and 300dpi at 24%. The higher the dpi, the smaller the rint size in general. Help, anyone?

[Mb]

Higher resolution creates higher quality prints (to a point) but not bigger prints. Higher resolution images have more pixel information per square inch (dots per inch) than lower resolution ones; the size of the pixel changes rather than the size of the image. This extra detail doesn't come from nowhere, though. A 300 dpi document is actually roughly 4 times the size of a 72 dpi document because each square inch of the image, when printed, will have 4 times as many dots.

Viewing at print size is just like printing--apparent image size remains constant regaredless of resolution. A computer monitor's resolution happens to be 72 dpi, so a 72 dpi file displays at the same size printed and onscreen. A 300 dpi document, however, as we already know, is four times the size of a 72 dpi document. Thus it has to be viewed at 1/4 size (technically 72 / 300 = 24% original size) onscreen to appear the same size as the 72 dpi document (the print size.)

I realize this isn't very clear; I would try to explain it better (with a diagram) if I had more time. But this is what you need to worry about: higher resolution means better quality printing; I usually use 300 dpi. There is nothing wrong with what you describe.

[strata]

for me 300 dpi usually displays the absolutely correct print size... I mean if I open up a 21x29.7cm 300 dpi document and press show print size it'll show an A4 on screen, but if I do it with a document of the same size at 72 dpi, it'll be, as said, roughly 4 times smaller... so I use it to check paper sizes and such too... oh well