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04/07/2006 05:17:26 AM · #1 |
I have read How to remove a colorcast by moodville and i noticed her way of finding a grey point was to hunt and search for it. I never seem to find people who have a systematic system to finding the grey point, so I thought I would share my way to find it using the actual pixel data so that you would spend less time hunting around in the photo for it, or if on a poor monitor, have some confidence it is correct. This is done for photoshop CS2.
It is simply an addition to moodville's method using the threshold and curves for Color Cast. I do this step just before finding white and black points.
1) Layer->New Fill Layer->Solid Color.
Click Ok and when asked to select a color go to your swatches menu and select 50% grey(top right corner of swatches), then click ok. If you don't have a swatches menu use Windows->Swatches.
2) Your screen should be all grey. Go to the to the Color Fill layer and switch the layer mode from normal to difference. Your photo will appear to be on drugs.
(From here you can follow moodville's example of finding the black point of an image but i will try to explain it anyway.)
3) Create a threshold adjustment layer and you will see a histogram come up. Pull the slider all the way to the left, then slowly move it to the right until you see the first black spot and press ok. This spot is middle grey of your photo.
4) Select the Color Sampler tool and zoom in on that spot. Then I double click on the threshold layer again and slide the slider back one number at a time until i get the first black box to appear and click ok. Use the Color Sampler to select this spot.
5) Discard the Color Fill Layer and follow moodville's steps to finding the white and black points. You can use the same threshold layer to do this.
6) When you bring up your Curves dialog box select the middle eyedropper to set the grey point and use the color sample you had selected in step 4.
I hope this helps some people, even more i hope it makes sense to some people! This was shown to me by a friend of mine and i don't know if he read it from a book or not, but i am not trying to steal anyone's idea or hard work. I just thought it might be helpful.
Message edited by author 2006-08-11 01:44:09.
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04/07/2006 06:00:15 AM · #2 |
Originally posted by jdannels:
Your photo will appear to be on drugs. |
LOL - Actually laughed out loud at this..hehehe
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04/07/2006 12:39:09 PM · #3 |
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04/07/2006 12:45:05 PM · #4 |
Originally posted by jdannels:
2) Your screen should be all grey. Go to the to the Color Fill layer and switch the opacity from normal to difference. Your photo will appear to be on drugs. |
Don't you mean "switch the layer mode from normal to difference"?
Good tip.
R.
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04/07/2006 05:40:57 PM · #5 |
Don't you mean "switch the layer mode from normal to difference"?
from Bear_Music.
Yes thats what i meant, but it was very late and i couldn't remember the word "layer mode." thanks for the catch |
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04/07/2006 05:46:42 PM · #6 |
Originally posted by jdannels:
moodville's method - moodville's steps |
what's that? link? |
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04/07/2006 08:35:55 PM · #7 |
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04/07/2006 09:07:42 PM · #8 |
Actually, if you let the computer pick a set of pixels that's the closest to 50% gray, it will do just that...what you are trying to do is pick the set of pixels that is supposed to be 50% gray...which isn't gray, and clicking it as your midpoint, thus making that 50% gray, and shifting the minor color imbalances in the rest of your photo...make sense?
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04/07/2006 11:15:25 PM · #9 |
Originally posted by biteme:
Originally posted by jdannels:
moodville's method - moodville's steps |
what's that? link? |
tutorial linked in original post was written by moodville.
David
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04/08/2006 07:11:48 PM · #10 |
| makes sense on what the computer picks as grey and what i really want to be grey. but if your photo is taken with the wrong white balance then that grey that computer chooses is off and this corrects it. atleast thats what it seems like to me, please correct me if am wrong. And i apologize to moodville for the gender misidentification. |
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06/07/2008 12:56:38 PM · #11 |
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06/07/2008 01:04:38 PM · #12 |
You said HER in your original post. :)
Thanks for this. |
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