For portraiture you can go as low as 180 dpi and have an "Acceptable" print. Of course, as Andy points out, the smaller the print, the higher the resolution, the closer you have to look to see the quality. But from a few feet away, for domestic use (Not in a gallery/exhibition) hanging on a wall, you can easily get away with 180DPI. IMHO especially in black and white where we are used to seeing "Grain"
On Mon, Mar 6, 2017 at 7:16 PM Andrew Davidhazy <andpph@xxxxxxx> wrote:
I think that it also depends on what it is that the photograph is all about. A solid color for example I think could be printed larger than one full of fine detail. Also, it depends on what the person’s criterion of “quality” is. Some people are pickier than others. And of course, viewing distance … factors that have their roots in the film era! Methinks!
Andy
> On Mar 6, 2017, at 8:06 PM, karl shah-jenner <shahjen@xxxxxxxxxxxx> wrote:
>
>
> Emily writes:
> 5.5 x 6 at 300 dpi
>
> Divide total pixels by dpi for decent print. Could be 200 or 300 for a print that small.
>
>
> Emily is quite correct - for a straight print
>
> but depending on the level of detail in the image, it's possible with the appropriate RIP to print the image quite a lot larger and have it look fine. RIPs (raster image processing) can be hardware or software and can vary based on use - RIPs exist for a variety of purposes, you'd need to look at a photographic RIP. Software based RIPs can be quite simple but often expensive .. hardware rips even more so, except that printers themselves have RIPs onboard that often can do the job surprisingly well.
>
> to use the RIP in the printer the technique is to load the image in a *simple* image viewing program, even something like a browser, then select print and specify the size you want the image to be - nothing more or less than that. The prinetr it's self will apply the algorythms and fuzzy logic required to upsize the image and produce the best image it can without pixellation.
>
> Often this ability (the RIP at work) is mistaken for a dpi setting below the normal quality barrier (300 ppi) - it's not usign a lower ppi at all but rather an interpolation programmed into the printer.
>
> Easiest way to see whether the printer can do a good job is to print it and see if it looks good as mentioned above.
>
> If you're not impressed, try a trial, free or commercial RIP and see if it can do better..
>
> buty basically Lea if you start with a 1770 x 2041 image then as Emily said, without introducing additional guessed data, 5.5 X 6 is as good as it gets.
