photo-editing


Unsharp Mask

Yes, the name is backwards. The "Unsharp Mask" tool in Adobe Photoshop and other programs does exactly the opposite of what the name implies--it sharpens pictures. But, it does it by emulating an old photography sharpening trick. It also happens to be one of the best tools in the photo editor's drawer.

Darkroom photographers discovered a trick for making pictures appear sharper. They would start with the negative they wanted to print, and would develop a positive of the same image. When they went to print the negative, they would shine the image through both the positive and a sheet of glass. The end result would be that the image would "stand out" more.

Photoshop does almost exactly the same thing, only with pixels instead of glass. Inside the computer's memory, it produces a negative image of the one on the screen. Black dots in your picture are white in the negative. It blurs this negative, just a little bit, and then it compares the two images, pixel by pixel. In areas where there isn't a lot of difference (like sky), the unsharp mask doesn't make any changes. But, in areas where there's plenty of detail, the original is going to be very different from the blurry negative, and that's where the program goes to work. It makes slight changes to the pixels between areas of different colors, making those borders "stand out" and, in effect, making the picture look sharper.

The three controls for the Unsharp Mask program control how much of an effect it has on the picture. Amount will differ with each picture. A Radius bigger than .8 starts to affect pixels away from the actual edge, so it's a good idea to keep this number low. And you'll probably want to keep Threshold as low as possible, too, because anything over zero affects the "grain" of the image.

 

 

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Photo Editing


Photo Editing Overview

... interpretation. Photos tend to be trusted more, because they accurately depict what was in front of the camera at the moment the picture was taken. At least, photographs are supposed to be accurate. How easy is it to edit a photo so that it shows something different than what really happened? The concept ... 

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Sharpening

... and sky blue on the other. The camera has to analyze where two colors touch, and then it has to "guess" at what color the dot in between them is really supposed to be. Most of the time, it's going to be some average shade between the two colors. This fools the human eye--because we see that averaging ... 

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History - Deluxe Paint

... groundbreaking case, but it showed an interesting viewpoint on the use of photo editing programs. Even though it was originally released in 1985, Deluxe Paint had many features that are still considered revolutionary today. It could do transparent backgrounds, animation through color cycling, lasso selection, ... 

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Burning And Dodging

... section of a picture. The photographer makes his print normally, and then masks off a large section of the print, usually with his hands. Then, with the light blocked, he adds a bit more exposure time to the print, so that the area that wasn't masked gets more exposure. Dodging, on the other hand, involves ... 

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Workflow: The Digital Darkroom

... entire image. Color balance, contrast, brightness, and cropping, for example. If you're working with RAW images, you have a lot more control at this stage. Once the large adjustments are made, it's time to focus on the smaller ones. Are there areas of the picture that could use cloning (like painting ... 

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