Photo Enlargements and Image Size

so I've been doing some reading about setting image size in photoshop, pixels, resolution, etc. without getting into those potentially confusing topics, my question is about the need for resizing a photo at all.

I alway crop my photos to 8x10 and just let the resolution fall where it may (I use an XTi). If I want an enlargement, I dont' create another version with a different image size, I simply order a larger print of that same photo with the same proportions (ie. 16 x 20). Am I doing myself a disservice by ignoring print size settings, or is there some real benefit to setting the planned print size in photoshop?

Again, I'm not talking about upscaling. I'm talking about a larger print that would have a lower resolution than the 8x10 version.

thanks for any help.

ryan

It depends on what the printer wants to accept. The pro lab I use wants 300ppi images. Your 10MP Xti image and my 40D images are the same 3888x2592 pixels. At 300ppi the dimensions are about 13x8.6 inches. If you want any other print size but 13x8.6 you or the printer software will have to interpolate (upscale or reduce).

The fact that you do nothing may not hurt things much if the printer or lab software does a good job of interpolation but some swear by some software like Qimage that does resizing. I've looked at the samples and IMO Photoshop does well enough. If I made prints professionally it may be worth paying for some good software but for me it's not worth it.

Like I said, Photoshop does about as well as dedicated software, however bicubic Photoshop resizing appeared much better than some printer driver interpolation.