Three little birds

[Copy_Kot]

We had great light today and I managed to screw up just about every shot I took (while shooting and processing), I need to work on my sharpening skills a little... and figure out how not to get JPEG artifacts.

Anyway, here are three from today. I thought I would mess around with them a little before I delete them.







I think I learned from today's mistakes and hopefully I wont repeat them.

Thanks for looking.

[Sushigaijin]

Hi paul...

the easiest method of sharpening to avoid artifacts is to copy layer, sharpen, then mask off everything that doesn't need sharpening. For high-res images, I use a very large radius (10px or more) at a very low amount (2-5%), and go from there. Sometimes you can get away with a second sharpening at about 0.3 px and 65% or so. For web images, I typically use about 0.3 px and about 70-100%. Your mileage will vary because of native sharpness differences. The "smart sharpen" tool in CS2 is great, or you can use the same settings with high pass sharpening. I almost NEVER use USM anymore because it sharpens indiscriminately - I prefer to only sharpen the things that are supposed to be sharp. Of course, everyone has their own methods, and these are just what work for me.

[Copy_Kot]

Thanks Erik, that is helpful.

[OBie]

Hi paul...

the easiest method of sharpening to avoid artifacts is to copy layer, sharpen, then mask off everything that doesn't need sharpening. For high-res images, I use a very large radius (10px or more) at a very low amount (2-5%), and go from there. Sometimes you can get away with a second sharpening at about 0.3 px and 65% or so. For web images, I typically use about 0.3 px and about 70-100%. Your mileage will vary because of native sharpness differences. The "smart sharpen" tool in CS2 is great, or you can use the same settings with high pass sharpening. I almost NEVER use USM anymore because it sharpens indiscriminately - I prefer to only sharpen the things that are supposed to be sharp. Of course, everyone has their own methods, and these are just what work for me.

Huh??!! That entire paragraph is Greek to me. Can someone point me to a thread or a webpage that would explain:
jpg artifacts
sharpening (I know what it means, but have no idea how to do it correctly, or when)
USM

Although I have PS at the office, I do my personal photo editing at home on a MAC. Looking into purchasing Aperture for the MAC, so I need some reference to that program.

Thanks for any directions pointing me to info about the above.

[Copy_Kot]

OBie, I was hoping someone with more knowledge would answer your questions. Here is my feeble attempt... JPEG artifacts occur when you convert a large file into a smaller one. It's kind of like trying to cram a puzzle that might measure 48 inches by 48 inches into a frame that only measures 24 inches by 24 inches... you will end up with pieces (pixels) that overlap or get pushed out of place. When you sharpen an image, you are rearranging the pixels to make your image look sharp (lol). There are many different methods of sharpening, some work better than others... you don't want to rearrange your pixels so much that you get halo's and other distortion's.

[OBie]

Thanks Copy - fortunately I found a Digital Photo mag from last year and while looking through it last night, I found several pages of instructions for PS2 - including several techniques that are constantly mentioned in these forums, like 'unsharp masking' - a term that really, really confuses me. So I'm off to read and hopefully learn.

Thanks!