Sharpness
Posted: Fri Nov 14, 2008 11:13 am
Carol: Doesn't look sharp to me on my monitor. Sharpening is tricky business. If you sharpen globally, You'll make the sky look worse, the more you sharpen the foreground. I have been doing more and more selective sharpening of my images, lately.
I moved my website and the new site allows much larger images to be displayed (essentially, up to the size your monitor will allow). All the images on the old site were limited in their pixel dimension, so they wouldn't show at the larger sizes, so I have been re-working them all, gradually.
You really need to get some expertise on your selection technique to do this effectively. For example, in your photo, I would select the sky (you could do the opposite--select the foreground--remember you can switch back and forth using "inverse" under the selection menu--there is probably a shortcut for that too) and then sharpen the foreground but not the sky. I even occasionally will apply a touch of "gaussian blur" to the sky (usually .5 +/- pixel or so), so it looks a little smoother. The trick in your photo is selecting the sky around those bare branches at the top left.
I use the "magic wand" tool a lot as my starting point (the "new" "quick selection" tool that is the default tool just doesn't seem to work for me--I may need to adjust some tolerance settings--the original "magic wand" is under that tool--just right click and select it from the drop down). After you click once somewhere on the sky, you hold the shift key and click again and you can add to the collection. If you hold down the alt key and click you can subtract from the selection. You can adjust the tolerance level on the top bar -- what it is doing is selecting the same or similar pixels.
Once I get a rough selection I use the quick mask tool (at the bottom of the tools palette-- and either the brush or eraser tool to clean up the unselected areas. So far, so good.
Now comes the tricky part. If you don't get a good transition between the sky and the edge of, e.g. the trees, you'll get a funky looking line there. In the old days, we used to "feather" the selection. Now I use the refine edge command. The gurus say using the radius slider gives better, smoother results than feathering. You also have a slider to contract or expand the edge. You have to think about what you are doing. When I apply the blur, I leave some "breathing room" so a tiny sliver of the sky won't be blurred (because I don't want to unintentionally blur the edges of the foreground objects). If I am sharpening, it really depends on the nature and look of the transition. Often, I'll do just the opposite, because I am willing to sacrifice a sliver of the sky (your eye won't see the graininess in that) to be sure the foreground object is sharp even at the edges.
There are some even more sophisticated sharpening techniques, which are too complex to discuss here (basically using "masks") which I will do on a "busy" image.
I moved my website and the new site allows much larger images to be displayed (essentially, up to the size your monitor will allow). All the images on the old site were limited in their pixel dimension, so they wouldn't show at the larger sizes, so I have been re-working them all, gradually.
You really need to get some expertise on your selection technique to do this effectively. For example, in your photo, I would select the sky (you could do the opposite--select the foreground--remember you can switch back and forth using "inverse" under the selection menu--there is probably a shortcut for that too) and then sharpen the foreground but not the sky. I even occasionally will apply a touch of "gaussian blur" to the sky (usually .5 +/- pixel or so), so it looks a little smoother. The trick in your photo is selecting the sky around those bare branches at the top left.
I use the "magic wand" tool a lot as my starting point (the "new" "quick selection" tool that is the default tool just doesn't seem to work for me--I may need to adjust some tolerance settings--the original "magic wand" is under that tool--just right click and select it from the drop down). After you click once somewhere on the sky, you hold the shift key and click again and you can add to the collection. If you hold down the alt key and click you can subtract from the selection. You can adjust the tolerance level on the top bar -- what it is doing is selecting the same or similar pixels.
Once I get a rough selection I use the quick mask tool (at the bottom of the tools palette-- and either the brush or eraser tool to clean up the unselected areas. So far, so good.
Now comes the tricky part. If you don't get a good transition between the sky and the edge of, e.g. the trees, you'll get a funky looking line there. In the old days, we used to "feather" the selection. Now I use the refine edge command. The gurus say using the radius slider gives better, smoother results than feathering. You also have a slider to contract or expand the edge. You have to think about what you are doing. When I apply the blur, I leave some "breathing room" so a tiny sliver of the sky won't be blurred (because I don't want to unintentionally blur the edges of the foreground objects). If I am sharpening, it really depends on the nature and look of the transition. Often, I'll do just the opposite, because I am willing to sacrifice a sliver of the sky (your eye won't see the graininess in that) to be sure the foreground object is sharp even at the edges.
There are some even more sophisticated sharpening techniques, which are too complex to discuss here (basically using "masks") which I will do on a "busy" image.