What's the verdict on random resolutions?

You're setting yourself up to output to print. Let's keep things familiar and say that an inkjet is going to handle the job. I got an email from an Mpix representative the other day that said Mpix printers print at 250ppi resolution. The guy down the street at Calumet photo uses a really nice, big, expensive Epson and he told me that Epsons "like to be at either 240 or 360, and nothing else."

Other reliable sources (Deke McClelland for one) say "Avoid resampling whenever possible; adjust your print size and leave the resolution at whatever it may be, because it's better to print at a different resolution than to add or remove pixels by interpolating."

Hmmmm. So if I send off to Mpix, do I lock the res at 250 or let it ride? And how about that fancy Epson down the street? What if I entered 8x10 in my print size dialogue (no resampling) and it spits out 293.6 ppi?

What's a boy who's heard conflicting information to do?!

Well, unless you shoot at precisely the amount of pixels prescribed for the required final image dimensions and DPI, then you are going to have to resample at some point.

Better that you control the resampling to final size (pixel dimension) and resolution (dpi appropriate for output device) than have someone/something else do it. Also, because output sharpening is sensitive to pixel dimensions, you should prepare your output for the specific device and apply the appropriate output sharpening at final size/res.

kirk

kirkt wrote in post #16224524
Well, unless you shoot at precisely the amount of pixels prescribed for the required final image dimensions and DPI, then you are going to have to resample at some point.

Better that you control the resampling to final size (pixel dimension) and resolution (dpi appropriate for output device) than have someone/something else do it. Also, because output sharpening is sensitive to pixel dimensions, you should prepare your output for the specific device and apply the appropriate output sharpening at final size/res.

kirk

So you are recommending setting the resolution to what the specific printer or company is recommending - for example 250 in my Mpix comment above, and resampling from there? I think that is what I gathered from your reply.

Also, maybe anyone who chimes in on this thread could give any insight to my other one I just posted a few seconds ago; it is somewhat related but warrants its own thread.

https://photography-on-the.net …p?p=16225261#po​st16225261

Because of the fact that digital printers use software that resamples images to "fit" the particular printer's "working resolution", you can actually choose what approach "works for you". For example, if you have a home/office printer and software installed that can work with that printer, you may find it totally acceptable to just edit and print using that software without bothering to resize to a particular "working resolution". All your editing work, including "output sharpening", is done to the image "as it stands". And plenty of external providers will accept and work with images that have not been "resampled", but just have the "native" resolution.

However, you may want more control of the process, as Kirk describes...it's up to you. Also, some external print services do have "best practice" guidelines. Ask them and follow their advice.

Of course, if you are processing for smaller prints, say 8x10 or smaller, then it can be handy to resize your image to the planned print size in inches and a ppi that will deliver good quality. A ppi of 300 is considered "standard", although the Epson printers evidently work best with 360 ppi.