Using Auto Color To Remove A Color Cast

[scottbergerphoto]

A quick and easy way to remove a color cast is to use Auto Color, (Shift+CTRL+B). The workings of Auto Color are hidden in the Options section of the Curves dialog box. To make Auto Color a better tool:
1. Opening up Curves (CTRL-M) and Select>Options.
2. Click on the Black swatch (Shadows) and in the Color Picker set RGB = 10, 10, 10.
3. Click on the Grey swatch and in the Color Picker set it to 128, 128, 128.
4. Click on the White swatch and in the Color Picker set it to 240, 240, 240.
5. Select Snap Neutral Midtones and Find Dark and Light Colors.
6. Save as Defaults (Thanks Leo)
7. Select OK
Now whenever you use Auto Color those will be the defaults.
Another great tip from Photoshop CS for Digital Photographers by Scott Kelby.

[PacAce]

I just wanted to add one note to Scott's excellent suggestion. The "Find Dark and Light Colors" will not always remove color casts, especially if the cast is strong. In that case, the other option to try is "Enhance Per Channel Contrast".

And one step Scott missed to make the Auto Color options you just set the default is to check the "Save as Default" box before clicking "OK". :)
[Edit: OK, just discovered that if you don't check the "Save as Default" box, PSCS may ask you if you want to make the new settings the new defualt, depending on which options were changed.]

[scottbergerphoto]

Thanks Leo. Correction made.

[Redbird_xo]

I just tried the above method and it works really well on pictures with moderate color problem. A huge timesaver for JPEGs. A big thank you to Scott and Leo.

[scottbergerphoto]

;)
See one, do one, teach one!

[alfa1six4]

Thanks! I just made the adjustments, really works well.

[GyRob]

thanks thats a handy thing to have .
Rob.

[colliewalker1]

A quick and easy way to remove a color cast is to use Auto Color, (Shift+CTRL+B). The workings of Auto Color are hidden in the Options section of the Curves dialog box. To make Auto Color a better tool:
1. Opening up Curves (CTRL-M) and Select>Options.
2. Click on the Black swatch (Shadows) and in the Color Picker set RGB = 10, 10, 10.
3. Click on the Grey swatch and in the Color Picker set it to 128, 128, 128.
4. Click on the White swatch and in the Color Picker set it to 240, 240, 240.
5. Select Snap Neutral Midtones and Find Dark and Light Colors.
6. Save as Defaults (Thanks Leo)
7. Select OK
Now whenever you use Auto Color those will be the defaults.
Another great tip from Photoshop CS for Digital Photographers by Scott Kelby.

During editing of scans from 35mm negatives (professionally made at 2700dpi:16 bit) I have made extensive use of the DCE Tools Auto Enhance plugin for Photoshop and I am very impressed with it's performance, making images which already seem pretty good, much better. However, DCE's Color Cast Correction has not worked very well for me - I find that the colour cast swings from one colour to another and I seldom arrive at a colourcraft free image.

Using scottbergerphotos posting above I have had a little more success - but not a lot!:cry:

I would be interested to know if other members find the colorcast problem as difficult to solve as I do.

I must sat though, that oftenDCE indicates a colorcast(usually red, cyan, yellow) that I can't detect - so DOES IT MATTER!:lol:

PS Could the fact that the scans are made from 35 year old Kodachrome slides be a factor?

[scottbergerphoto]

What don't you like about the results of Auto Color? Usually the image looks a liitle dim after Auto Color and you need to drag the middle of the curve up a little.
Have you tried the Grey eyedropper in Levels?

[colliewalker1]

What don't you like about the results of Auto Color? Usually the image looks a liitle dim after Auto Color and you need to drag the middle of the curve up a little.
Have you tried the Grey eyedropper in Levels?

I have been editing 38 photo scans and in none of these would I have recognised a colour cast : however, the DCE Tools plugin includes a colour cast correction feature and after using Autoenhance ( this works exceptionally well and I would not be without it) I did a check and in all cases it indicated a colour cast – usually red/cyan or yellow.



I found that neither Autocolor or DCE Tools would correct the cast on their own: using DCE, in most cases the colour cast just changed from one colour to another.



Eventually I found that using Autocolour – then DCE in a ‘to and fro manner’ several times, I removed the colourcast from all but 2 of the photos; in those cases I am happy to accept what I have. Your advice about lifting the curve worked very well as a finishing touch



Curiously, in the Curves Dialogue Box, the 240 setting insists on changing itself to 255!



I got there in the end although in an unusual manner: perhaps this is connected to my PC’s sluggish performance – AND tendency to a ‘mouse freeze’ when photo editing;some of the tiff files are very large e.g. 20MB + and I am beginning to wonder if although I have 512MB RAM this is adequate. My O/S is Windows XP and it is sending a lot of error messages ( no doubt a waste of time) to Microsoft.

I tried the Grey eyedropper in Levels on the more awkward ot the two 'rebel images' but the entire photo turned a pale green.....!


I am glad to have been tipped off about Autocolour which I’ll always use now - thanks for the tip Scott.

Best wishes - Denis

[scottbergerphoto]

Curiously, in the Curves Dialogue Box, the 240 setting insists on changing itself to 255![/font]


You need to check: Save as Defaults