Sizing photos for print

[Ultra Magnus]

I was wondering, should I resize my photos in PS to the size I want to print them? For example, say my printer prints 300ppi, and I want a 8 x 10, should I resize it to be 2400 x 3000 pixels, or 1200 x 1800 for a 4 x 6? I started thinking and if I send a much larger resolution image to my printer than I'm going to print it at, then I'm essentially making the printer resize my photo internally, right? I know that when I resize a photo on my comptuer, the always come out less sharp, so then are my photos coming out less sharp on the printer? Would the same go for online professional printing?

I intend to do a comparison but I hate wasting ink...

Thanks.
BM

[Photo-John]

Good question. Experimentation is the best way to find out. But it is nice to find out what other people have learned. You say that when you resize you lose sharpness. Every time you resize you will need to apply unsharp mask. Because resizing always either adds or removes information and in doing so changes the sharpness of your image. I use unsharp mask both for printing and when posting on the Web. But I apply it very differently.

Printing isn't quite the same as just resizing. I like to print from files that are less than 300 dpi. I find that allowing the printer to interpolate a bit delivers prints that I like better. Printers do their own interpolation. It's called "hardware interpolation," and it uses the actual printing process to enlarge your image. I think it smooths out images and makes them look better than just resizing to 300 dpi and sending your file to print. You might see things differently than me, though. The best thing would be to get opinions from three people, try all of their methods, and see what you like best.

[Ultra Magnus]

I think you talked me into it. I'll try to print the same photo, three times at different DPI and see how it turns out...

BM

[another view]

With 8x10 or 8x12 and smaller, I've always re-sized to 300dpi and been happy with the results. John's comments make me wonder about trying other resolutions though - I've done 240dpi for larger prints and they look great (not better, but no equal comparison either).

I resize for two reasons. First, when I order prints the download time is reduced because I'm not sending any more data than needed. Second, I know what the file looks like so I know I'll be happy with the prints. You'll be best to start with the original file (or an un-sharpened PS'ed file), change the size of the final image and then use USM as needed.

[Ultra Magnus]

I normally, for "good" photos save all the edits in a PS file, flatten and sharpen/resize/crop/etc., save as .jpg for email or print. For snapshots, I just make a jpeg with the suffix "- edited" and do whatever with them later...

[Photo-John]

It's good to experiment with sharpening, too. I change settings and strategy from image to image, and over time.

[another view]

I change settings and strategy from image to image, and over time.

It's funny how a shot from a couple of years ago that you thought was really good is really crap based on editing - well, at least that's happened to me!