WOW!!! I asked what I thought was a reasonably simple question... and all hell broke loose with over 90 replies, most of which went completely over my head! And I went to 23rd grade! What an incredible forum.
I get a sense that the sharpening routines in Lightroom are the basic equivalent of Photokit except for the "creative" sharpening aspect and that output sharpening part can be done in Lightroom, or with Photokit. Is that the jist of these 90 replies?
Frankly neither do I care about nor do I understand "deconvolution," and many of the other complexities discussed in this thread.
Most sincere thanks to everyone for all their comments. Now all I have to do is finally decide what to do. Can I learn how to sharpen in Lightroom? I hope so. It's a lot cheaper than the hundred dollars for Photokit though I have the trial and will see if I want to actually purchase it.
Eric, I sympathize with you completely. YES, sharpen in Lightroom - it's fine! And it's not rocket-science. Here's a practical guide for how to apply it:
The image needs to be at 100% display magnification to see the effect. You get a better impression using the B&W feature which shows in the little preview window above the sliders by doing ALT-Click on the individual sliders.
Radius: Lower values give more narrow edge detail. Use values below 1 for high frequency images and values above 1 for lower frequency images. (Frequency refers to the predominance of fine edge detail).
Detail: It distinguishes edges from halos. Lower values suppress halos and allow the use of a higher Amount for mor edge sharpening; higher values accentuate halos and show more of the sharpening effect.
Masking: Increasing it blocks out more area of lesser interest for sharpening. What is masked shows as black in the little preview window with ALT pressed when you slide the Masking control.
Amount: The extent to which detail and radius are applied. Higher amounts apply them more strongly.
The only way to master this is to examine what you are doing on the display (experiment with several types of images), note the numbers you use, and print the image. Look at the results on paper. Experiment until you develop prototypical settings which give you the appearance in print you like.
More often than not I simply use the Presets in Lightroom for sharpening - Landscape and Portrait, because on the whole, when you apply them to those respective kinds of images they really do deliver nice results.
For output sharpening in the print module - it's quite mechanical. There are only two settings, one for paper type and one for strength - again do some experiments to see which combination looks best to you ON PAPER (note the PPI setting above the sharpening should be the PPI at which you want to print). The display is not a reliable place to judge the final impact of sharpening.