Output Sharpening + Image/ Canvas Size

[Jim Stewart]

Output Sharpeners require image to be at final size before application: is it OK to alter canvas size after applying Output Sharpener?

[Jeff Schewe]

Yes. . .but pick the image's resolution (and size if web output) BEFORE the canvas expansion. . .for print output, it's not so much the physical size as the final pixels/inch that are critical to be finalized when choosing the correct output sharpener. With the web & multimedia output sharpeners, it is the actual pixel dimensions that are important.

[Jim Stewart]

Thanks Jeff - just one other point: I often find I have to use the Scale to Fit Media checkbox in Print with Preview and make <1% adjustment to fit image to borderless page (however precisely I resize the canvas there always sems to be a slight discrepancy at this point). I guess this can throw out the sharpening too(?). Any thoughts...

[Jeff Schewe]

Yep. . .ideally you really should pre-check the print output size and do any changes in Image Size to get the exact fit BEFORE committing to the Output Sharpening. . .all tiny steps to getting optimum output. . .

[Jim Stewart]

OK - I guess I'll just have to sacrifice that last 0.04mm of paper coverage in the interests of sharpening accuracy!

Thanks again

Jim

[Jim Stewart]

I've looked further into this, and also found a work-around.
It seems that there is a built-in discrepancy between image dimensions shown in Image Size + Canvas Size dialogues and as Doc Dimensions at bottom left of PS screen, and those shown in Scaled Print Size within Print with Preview dialogue: thus the need I've always had to tick the Scale to Fit Media checkbox in order to get borderless print, even after sizing exactly to paper size in Canvas Size.
The only way I've found to rectify is to work-around as follows: in Canvas Size set New Size width & height to exact paper dimensions (i.e. for A4 297x210mm): go into Print with Preview (where Scaled Print Size will now be approx. 0.1 mm shorter on each side) and check Scale to Fit Media: note sizes created by this action, and go back into Canvas Size and insert these as new h&w values (for A4 they are 296.686mm x 209.903mm). PS will not show these values in bottom left of screen - on my screen at the moment they're showing as 296.67 x 209.89mm (!?), but they will show up exactly right in Print with Preview, and will not be affected by the Scale to Fit Media checker. So jeopardy to optimum output by scaling in Print with Preview is obviated.
Then apply output sharpener and proceed as normal.
Question remains, why does PS create this anomaly between 2 of its own dialogue boxes?
Hope this is of interest/ use to someone else out there...

Jim

BTW: PSCS/ OS X 10.2.8/ Epson R800, and the excellent PhotoKit Sharpeners

[jsalcedo]

Great tip, Jim! Thanks!
Jose