how hard should it be...

[acroyear]

...to get a simple answer to the following question:

What is the optimal resolution an image file should have to not look like absolute crap when enlarged to 5x7, 8x10, 8x12, a 12x36 banner, or a 12x24 poster?

My google-fu is failing me on this.

I keep seeing things either useless, or in "DPI" - I don't think "DPI", dammit, I'm looking at 3456x2304 and 3280x2460 and I want a straight answer dammit.  DPI is all about the printer - I don't care about the printer, I am asking about the source image itself.

(I also keep seeing sites about 5mp and "expensive memory", and all that is SO 3 years ago...).

Ok, one site is finally hinting that 7200x4800 (or 34mp) is best for that 24x12 poster, so that's out with what I've got... guess I'll go with a set of 8x12s mounted side by side.

of course, along the way I run into sites about resolutions to enlarging the european parliament, and high resolution images on other...enlargements...

oh well.  gotta go for now.

Comments

[javasaurus.livejournal.com]

Here is a very nice site with information on sharpening and interpolating enlarged images. It includes a handy resolution calculator near the bottom of the page -- enter the viewing distance and some other parameters, and it spits out your needed dpi.

[skivee.livejournal.com]

Javasarus is wise in his words. If you were viewing the banner at the same distance as the 8x10, then you would need a gagillian
mega-deca-pixals
If not, the increased resolution becomes less important proportionally as size is increased.

[acroyear70.livejournal.com]

well, yes it is meant for a wall poster (i already have the frame) so i'm gonna skip that idea and just go with multiple 8x12s with a little space between them.