Photo Gallery DK - Resolutions for laserprinting, graphic prepress films and photographic copying:

wanrong 2007-07-02

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Resolutions for laserprinting, graphic prepress films
and photographic copying:

In case the total size/resolution of a digital photo is known it will be easy to calculate the size of the photo in question for a specific reproduction method.

A digital photo having a total size of e.g. 3.000 x 2.400 pixels can be reproduced in the format 30 x 24 inches (76 x 61 cm) if the print method needs 100 DPI. The same photo can only be reproduced in the format 10 x 8 inches ((25 x 20 cm) if the print method needs 300 DPI.

NOTE: There are of course many differences in the various production methods so all data shown in the below scheme will only be guidelines.

DPI	LPI	LPC	Use
dots per inch / pixels per inch	screen lines per inch	screen lines per centimeter	Use
72	36	14,5	Screen
80	40	16
90	45	18
100	50	20	PostScript laser- & poster printers
110	55	22
125	62	25
150	75	30	Screen print
170	85	34
200	100	40	QuickDraw inkjet printers
220	110	44
240	120	48	News paper printing
270	135	54	Magazines, advertisements and print-on-demand
280	140	56
300	150	60	Common offset & magazines - photographic copying [1]
325	162	65
350	175	70	Exclusive offset & photogravure
375	187	75
400	200	80	Offset with stochastic screen

[1] NOTE: Photographical copying is a sublimation of halftones without the use of screen. The following 4 examples show the resolutions needed for photographic printing.

photographic print format	A resolution of 150 dpi gives an acceptable quality	A resolution of 150 dpi gives an optimal quality
4 x 6 inch / 10 x 15 cm	593 x 872 pixels	1186 x 1744 pixels
5 x 7 inch / 13 x 18 cm	738 x 1047 pixels	1477 x 2093 pixels
4 x 8 inch / 15 x 20 cm	844 x 1163 pixels	1767 x 2326 pixels
8 x 12 inch / 20 x 30 cm	1180 x 1744 pixels	2360 x 3488 pixels