Required resolution and print size

[Moglex]

I'm sure this is a FAQ but I can't come up with a search that finds an answer so apologies if it's been asked before.

Can someone point me to a discussion about the relationship between resolution and print size?

I realise this is not a question with a simple "x pixels is good for A3" answer but I'm sure it must be debated and discussed quite frequently.

TIA

 

[D-50]

You want to print at 300 dpi which means you need 300 pixels per inch. A 6mp camera's images are roughly 3000x2000 so at 300 dpi you could print a 10x6.5 (3000/300=10 x 2000/300=6.5) without altering your image. Although I have printed images from a 6mp DSLR at 13x19 and the result are acceptable.

 

[Big Mike]

Yes, the 'standard' is 300 PPI for photographic quality printing. However, you can get by with smaller sized images and larger prints...if you remember that larger prints are meant to be viewed from farther away. Billboards, for example, are certainly not printed at the same resolution.

Also, you can up-sample your digital files to increase the number of pixels. When you do this, you do loose quality because the software has to make up the extra pixels...but it works well for reasonable size increases.

 

[*Mike*]

300 is widely considered the standard, but it varies a lot by printer... Millers and MPIX actually print at 250ppi and I doubt anyone would question their quality.