Sharpening for fairly large prints

Cornflake

Somebody wants to order an enlargement to 24X36 of an old photo I took with a 10.5 megapixel camera. I seldom enlarge prints to more than 12X18 and now I have a camera with a lot higher resolution. I did some research and it looks like the photo should hold up at the sizes the buyer wants. But I'm never quite sure how to handle output sharpening for larger prints. Should I just tell Lightroom what kind of paper will be used and specify high sharpening? Any advice would be appreciated.

ziggy53

If you still have an original RAW file, straight from camera, you may want to interpolate the file using a recent, modern photo editing software to the desired size first. If the camera had an Anti-Aliasing (Nyquist/Low-Pass) filter over the imager, it's often best to do a capture-sharpen at the same time as the interpolation to working size. The capture sharpen should be just enough to counter the AA filter, or maybe a little less if you use any post-processing which increases contrast. I also like to do noise reduction at full working size and before most post-processing. (For a lower contrast scene, I do defer noise reduction until after post-processing, however. [I use Neat Image for some of my noise reduction, as well as the built-in NR in PhaseOne CaptureOne Pro. Both work well in an interpolated workflow.])

Now do any required post-processing you did for the original.

After you achieve the desired overall look, apply your output sharpen to taste at 100 percent (1:1) viewing size. (Some folks like to use 50 percent viewing for a lower-resolution original RAW.) I often take an 8" x 10" crop from the important part(s) of the image and print that/those crops locally to confirm the look is appropriate, before sending the complete file to be printed.

Cornflake

Thanks, ziggy. That's very helpful.