USM parameters........

I have seen references in a couple of posts on the forum (not here specifically) as to parameters of 300 for the amount, 0.3 for radius, and 0 threshold (i'm using CS2 and have a 30D).

Could someone fill me in as to how these particular parameters have been circulated/determined - or the origins of these recommendations? I have seen some passing reference that canon recommends these settings?? Is this is general USM recommended for canon's images from the camera to always be applied? (I'm shooting JPG still, not RAW, will do that soon, I'd like more experience with the camera first)............

Thanks in advance for filling me in.

Sharpening is a pretty individualized thing, actually. I don't use USM at all, preferring instead to use a high pass action. The settings you've listed may be from one of Scott Kelby's Photoshop books.

pigtailpat wrote in post #3546025
I have seen references in a couple of posts on the forum (not here specifically) as to parameters of 300 for the amount, 0.3 for radius, and 0 threshold (i'm using CS2 and have a 30D).

Could someone fill me in as to how these particular parameters have been circulated/determined - or the origins of these recommendations? I have seen some passing reference that canon recommends these settings?? Is this is general USM recommended for canon's images from the camera to always be applied? (I'm shooting JPG still, not RAW, will do that soon, I'd like more experience with the camera first)............

Thanks in advance for filling me in.

That's the USM values recommended in page 4 of the 1DmkII "Tips and Techniques: Camera Handling & Maximum Image Quality" doc written by Chuck Westfall for pre-sharpening a 1DmkII image coming straight out of the camera. You can download that document from:

http://www.usa.canon.c​om …ductID=4&articl​eTypeID=48

I also use Amount 300 and Radius 0.3.

But it's very dangerous to blindly stick to a constant Threshold setting. I use anywhere between 0 and 30, depending on the quality of the photo.

If you photo is very clean, and very low ISO, you can get away with 0 Threshold. But if there's any hint of noise in your photo, you'll need to crank the Threshold up.

Thanks guys. Would those recommendations work for an image coming from a 30D camera or no? I shall download the doc though.......

Thanks so much for clearing this up for me........

(PS that document - gives the following advise on the USM settings):

"From: Mr. Westfall's article: Canon EOS digital cameras have an anti-aliasing filter installed on the image sensor. This filter improves color rendition and practically eliminates moiré. The liability is a
slight reduction of sharpness. To reduce the softening effect of the anti-aliasing filter we
recommend applying an unsharp mask to the image in Adobe® Photoshop®. Although
there is no such thing as a “best” setting for all applications, we suggest the following
as a starting point:
Amount: 300%
Radius: 0.3 pixels
Threshold: 0 pixels"

Does this seem to include images from the 30D, or is he specifically referring just to the 1-D(etal) pro series and not to the 30D and lower??

I don't think your camera model will make a difference - the basic USM principles will apply.

Don't over-engineer things. Use the recommended settings as a starting point, make sure you're viewing the image at 100%, and adjust the settings to suit your own needs.

With a little practice, you'll soon know what level of sharpening is right for your photos.

Note that the reference is to what is called "Capture Sharpening", a slight initial sharpening to counteract the AA filter. Final "Output Sharpening" will need to be done after resizing the image at the end of the workflow and perhaps intermediate selective "Creative Sharpening". See this:
http://www.creativepro​.com/story/feature/203​57.html