It's impossible to give precise amounts as it's very image and size dependent.
Viewing your image on screen at 50% generally gives a very good representation of what the sharpened print will look like.
Posted by Phil Shaw on December 13, 2006 at 1:38 AM
Sharpening is subjective and depends on many factors including file type (RAW or jpeg), whether you are sharpening in Photoshop or other software, subject matter, print size and more. As indicated by John, prints generally need (or can take) more sharpening than images for the screen. And as suggested by Justin, the best way to judge this is to re-size the image to it's final size (A4, A3 or whatever), then view the critical parts of the image on screen at 50 percent (1 screen pixel = 2 image pixels). Assuming you are sharpening using USM, what you should be doing is applying an amount of sharpening that just starts to look "crunchy" i.e slightly over-sharpened on screen. This will look fine when printed. As a starting point you can use the following USM settings Amount = 300 (250-350); Radius = 0.9 (0.8 -1.2); Threshold = 2 (0-10).
Immediately after sharpening select Edit from the Menu Bar, then Fade Unsharp Mask from the drop-down selection list, then change the blending mode in the dialogue box from Normal to Luminocity. This will apply the sharpening to the luminocity channel rather than the colour information and will help to reduce the incidence of sharpening artifacts (haloes) in the image.
Posted by Sean Bolton on December 13, 2006 at 5:39 AM
Hi Andy
This is an open ended question and the answer depends on several factors including your original file quality, the subject (portrait, landscape, etc), the file size, the output medium (inkjet, lab printer) and the print software and driver (Photoshop, RIP, etc).
As a general rule I find for prints I need to sharpen a bit more than I would for a web image. I apply enough sharpening so that I just start to see sharpening artifacts appear in the subject.
I also use a lot of selective sharpening to emphasise eyes and other key points in an image. There is no point oversharpening a blue sky or an out of focus background.
I would recommend reading Ron Bigelow's comprehensive and readable articles on sharpening (and other PS techniques).
Discussion
5 repliesIf you're sending them off to get done, none. Let the printers decide how much they need.
John
Viewing your image on screen at 50% generally gives a very good representation of what the sharpened print will look like.
Immediately after sharpening select Edit from the Menu Bar, then Fade Unsharp Mask from the drop-down selection list, then change the blending mode in the dialogue box from Normal to Luminocity. This will apply the sharpening to the luminocity channel rather than the colour information and will help to reduce the incidence of sharpening artifacts (haloes) in the image.
This is an open ended question and the answer depends on several factors including your original file quality, the subject (portrait, landscape, etc), the file size, the output medium (inkjet, lab printer) and the print software and driver (Photoshop, RIP, etc).
As a general rule I find for prints I need to sharpen a bit more than I would for a web image. I apply enough sharpening so that I just start to see sharpening artifacts appear in the subject.
I also use a lot of selective sharpening to emphasise eyes and other key points in an image. There is no point oversharpening a blue sky or an out of focus background.
I would recommend reading Ron Bigelow's comprehensive and readable articles on sharpening (and other PS techniques).
Ron Bigelow Photography Articles
cheers
Sean
http://www.naturephotographers.net/imagecritique/bbs.cgi?a=vm&mr=13035&b=se&st=160&la=184&ph=166&sid=7965&u=7981
http://www.naturephotographers.net/imagecritique/bbs.cgi?a=vm&mr=1317&b=se&st=0&la=184&ph=17&sid=7965&u=8110