Nikolaich Posted January 25 Share Posted January 25 An ellipse with transparency 70 drawn on a layer with transparency 255 is different from the same ellipse drawn with transparency 255 on a layer with transparency 70. Why are the results different? Quote Link to comment Share on other sites More sharing options...
Tactilis Posted January 25 Share Posted January 25 Welcome to the forum @Nikolaich 2 hours ago, Nikolaich said: Why are the results different? On the left is a black ellipse drawn with an opacity (alpha) of 70 on a layer with opacity of 255. On the right is a black ellipse drawn with an opacity (alpha) of 255 on a layer with opacity of 70. I may have misunderstood what you are asking. Could you show us the differences you are seeing please? Quote Link to comment Share on other sites More sharing options...
Nikolaich Posted January 26 Author Share Posted January 26 I apologize, I didn't see the possibility to attach a picture. I'll show you an example. On the left is drawn an ellipse of white color with alpha channel = 70 and the layer is set to transparency 255. On the right, a white ellipse is drawn with alpha channel = 255 and the layer is set to transparency 70. See what I'm talking about? It looks like the right ellipse has antialiasing applied, but the left ellipse does not. Quote Link to comment Share on other sites More sharing options...
Nikolaich Posted January 26 Author Share Posted January 26 (edited) Why did the forum reduce the image for me? Now it can only be viewed normally at 5x magnification. I apologize, I misnamed the tool. I was talking about the ellipse gradient. My mistake. Edited January 26 by Nikolaich Quote Link to comment Share on other sites More sharing options...
Tactilis Posted January 26 Share Posted January 26 7 minutes ago, Nikolaich said: Why did the forum reduce the image for me? Take a screenshot. Crop it to the relevant area. And then just paste the image to the forum. Quote Link to comment Share on other sites More sharing options...
Nikolaich Posted January 26 Author Share Posted January 26 (edited) Edited January 26 by Tactilis Removed duplicated images Quote Link to comment Share on other sites More sharing options...
frio Posted January 26 Share Posted January 26 The gradient tool uses dithering to reduce the amount of color banding. The closer the colors are to each other, the more intense the dithering becomes and alpha counts as well, so alpha 255 to alpha 0 are maximally far from each other, but alpha 70 and 0 are much closer and get dithered harder. When you change layer opacity, there is no dithering, and you get the banding instead. Here's a synthetic comparison: top part is a gradient from RGBA 255, 255, 255, 31 to 0, 0, 0, 0, on a black background. The bottom part is a RGBA 255, 255, 255, 255 to 0, 0, 0, 0, with layer opacity set to 31. After merging the layers, the visibility was boosted with the levels tool to bring the 31, 31, 31 to 255, 255, 255. As you can see, the banding is intense on the bottom one, whereas the top one is very fuzzy but you can't really tell the banding. It's a tradeoff and you kind of just have to choose which is preferable for your use. 2 Quote Link to comment Share on other sites More sharing options...
Nikolaich Posted January 26 Author Share Posted January 26 Thank you for the explanation. Quote Link to comment Share on other sites More sharing options...
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