How to determine print size?

[iltriumph]

Guys,

If I know my pixel dimension (eg: 3008 by 2000, 900 by 600, ...) and photo size (eg: 2mb, 1 mb, ...) and want to print them at 200 to 300 DPI, what's the formula to calculate the print size? I mean, given the above factors, how do i know what's the biggest print i can go?

Thanks in advance for replying

 

[theRBK]

how big do you want to print it?

knowing how big you want, upsize the images, and see if the images are still sharp enough to be printed... zoom to about 33% to see if it is sharp enough, if not sharpen it some if possible... if still not acceptable, then maybe that particular image cannot be printed to your required size...

this is of course subjective to your taste... but really, whether an image can be printed to what size depends not only on the number of pixels it has, but also on its sharpness and your own acceptability of the enlarged sharpness... personally I have printed 4Mpixel images at 1.8m x 1.6m for shop frontage use...

 

[Squid]

If I know my pixel dimension (eg: 3008 by 2000, 900 by 600, ...) ..... and want to print them at 200 to 300 DPI, what's the formula to calculate the print size?

If you know the pixel dimension, then just divide the number of pixels by 200 or 300 dpi to get the physical length in inches. For example, 3008 pixels x 2000 pixels will give you 10 inches x 6.7 inches at 300 pixels/inch

If I know my .... photo size (eg: 2mb, 1 mb, ...) and want to print them at 200 to 300 DPI, what's the formula to calculate the print size?

A rough guide is

Length of the longer side of print in inches = 4 x SquareRoot(Megapixel)​

For example, the 4 megapixel camera, the length of the longer side of print would be 8"


With above information, selection of photographic paper size is based on listing below
3R = 3.5" x 5" (1,050 pixel x 1,500pixel)
4R = 4" x 6" (1,200 pixel x 1,800 pixel)
5R = 5" x 7" (1,500 pixel x 2,100 pixel)
6R = 6" x 8" (1,800 pixel x 2,400 pixel)
8R = 8" x 10" (2,400 pixel x 3,000 pixel)
S8R = 8" x 12" (2,400 pixel x 3,600 pixel)
10R = 10" x 12" (3,000 pixel x 3,600 pixel)
S10R = 10" x 15" (3,000 pixel x 4,500 pixel)

 

[Adelfin]

DPI = Dots(pixels) per Inch
so u choose ur dpi, then u divide ur image size accordingly. That would be the max size for that particular resolution.

For eg, if u want to print at 300 dpi,
Horizontal number of pixels / 300 = A"
Vertical number of pixels / 300 = B"
largest size possible = A" x B"

most smaller prints would ask for 200-300dpi, however, larger prints (think poster size) are a little more forgiving, and u could print as low as 100 or 72dpi, coz people won't really look so close if ur prints are that big..

 

[iltriumph]

Ok, thanks u guys for spenting time to reply. I understand it now liow