I submitted some photographs for possible use at a web stock agency and they sent me an email saying, "Please don't upsample your images. This severely degrades the quality. This image contains undue artifacts when viewed at full size."
I shoot digitally and use Photoshop to resize my photographs. I have no idea what I'm doing wrong!
Can you help?
A Sizable Problem
The first question I have for you is: How many megapixels does your camera shoot? Many stock agencies require a minimum image size, and if you want to sell a lot of stock, you may need to get a higher-megapixel camera.
Why? Because when you upsample, that is, when you go to Image > Image Size and type in a bigger Document Size while you’ve got Resample checked, you're inventing pixels that never existed before. And there are only so many pixels you can invent before your picture starts to look bad. Try blowing up a 4x6 image to 16x20, zoom in, and you'll see what I mean. The "undue artifacts" they're talking about are the leftovers from the interpolation process.
So to solve your problem, make sure you're shooting on the highest quality, highest resolution setting. And make sure your camera’s resolution is at least as big as the stock agency requires.
Hope that helps, and good luck,