[StiffLegged]

Just by coincidence, Phlearn have a bunch of videos going up this month for free entitled “30 Days of Photoshop”. For anyone wanting an introduction to Photoshop, it should be useful.

[biz-engineer]

Interesting feedback. As I can see, sharpness (or the lack of it) isn't quite the same if we compare 4 corners, and that may also vary from lens to lens (copy variation).

I found that:
- using one layer + mask per corner is the most flexible to adapt sharpening to each corner area
- the amount of detail that can be recovered via sharpening is limited due to forming of white lines at edges, but a little additional sharpening towards corners provides good results overall
- local treatment is best to avoid unnecessary increase of noise in areas such as skies that don't need any sharpening at all
- a little time consuming, but can be worth it for large prints

[Digitalis]

the amount of detail that can be recovered via sharpening is limited due to forming of white lines at edges,

There are sharpening techniques that do not create halos like USM does [High pass sharpening is one of them] but they have to be applied with care because when pushed to extremes image tonality can suffer.

a little time consuming, but can be worth it for large prints

The extra time spent on preparing an image for printing is always time well spent, after we are all committing Ink to paper with a potential longevity of 250 years*.


* though this figure can vary drastically, depending on the printing process used. Dye inks Vs Pigment inks, differing paper types have an impact though by far the biggest variable in print permanence is how the image is displayed. Under high quality glass, pigment inks on quality archival paper and museum grade matte board, away from direct sunlight and excessive heat and airborne contaminants - average longevity will be circa 180 years.

[biz-engineer]

Having photographs developped on paper unfolds another dimension, especially regarding preparation of digital files and regarding camera & lens requirements.