How can i select specific color and remove it in compositor? + Screenshot

Support Compositing and Post Processing
#1

Hi guys i have a two questions. First one - here is one of the scene during my space animation movie and at some frames i am not sure if i like this reddish tint coming from the sun. How can i select only that red tint and remove it. I remember something that i have to use eye dropper tool of the hue saturation node or other node? and pick that color and multiply it with something or mix it. I forgot. Can you remind me.

Second question - my sun is too bright at the middle area. So how can i tone down that only brightness in the middle.

Thanks!

HERE IS THE SCREENSHOT - http://www.pasteall.org/pic/show.php?id=104056

#2

Because simple color balance doesnt help so i want to use selective color method

#3

Keying-nodes for selecting?

#4

For the red color, take a look at the Hue Correct node. Grab the handle by the red part of the spectrum and drag it downwards to desaturate the red.

For the bright spot, there’s bunches of ways to single out the bright spot. Maybe use the Color Ramp node and bring up the blacks until you have just the brightest parts of the white. Or maybe single out the color channels using the Separate RGB node, and use a color ramp node on the channel that shows the middle the best. Then you can use that output as a matte for a color correct node, and you can reduce the brightness.

#5

Also if the image is a direct render or an EXR file you could use a tonemapping node to bring the bright spot down.

#6

Thank you guys, will try that later

#7

Generally speaking, in a CG-rendering pipeline, you really would prefer to deal with a problem “at its ‘(root) cause,’ rather than any sort of ‘effect,’ such as Color.”

If you had the foresight to structure your pipeline around MultiLayer OpenEXR files throughout, and to capture the necessary layers of information … “Damn the disk space, full speed ahead!” … then you should be able to address your problem much more precisely, and earlier in the pipeline, while incurring only a modest amount , if any, of possible (selective, targeted …) re-rendering.