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Color Correction with Colorwasher

Posted: Mon Nov 15, 2004 7:13 pm
by mdessureault
Hi,
I am working with the demo version of Colorwasher and would like to understand the product better before making a buying decision. One of my testing images was scanned and I can see in the histograms that 1) the shadows part is dominant (which often happens with scanned images) 2) there is a small blue cast in the highlights. I would like to 1) increase the highlights 2) remove the blue cast in the highlights. To increase the highlights I used the highlight slider to the right but it never worked. About the blue cast, I have no idea on how to proceed. Any suggestions on what to do?
I don't know if this information is appropriate but I make my tries in Corel Painter, which is not the best product for color correction.

Michèle D.

Posted: Tue Nov 16, 2004 12:16 pm
by HaraldHeim
Can you please send me the mentioned image by email? That way, it would be easier for me to give you detailed instructions.

To move the shadow areas into the midtones and highlights, you need to use the Shadows slider and not the Highlights slider. Using the Exposure slider may work better in some cases.

To remove the blue cast in the highlights you can try pressing the Auto 3 button. Alternatively you can draw a sample area on the preview.

Posted: Tue Nov 16, 2004 12:54 pm
by mdessureault
Hi Harald.

Thank you for your answer.

My photo is a more than 2M TIFF image and I am on dialup. So, I have to think about what I will do to send it to you.

The slight blue overcast in the highlights is AFTER sampling a small area that should be white. I am familiar with the white point technique and I am happy I can use it with your(?) plug-in. Now, with another area, too much red.

In fact, the meaning of my question is more how to get rid of slight overcasts in midtones or highlights after the white point. I have a very old version of Photoshop (3.0) that doesn't work on Win XP and I don't have the means to upgrade (anyway, this is not my main tool. I use it only for color correction and sharpening) and I am looking for some replacement. PSP can do only part of the job (Lab colourspace is not available) and Painter, forget it.

In my tests I try to do what I mostly do for colour correction in Photoshop: adjust levels and adjust variations. Sometimes Adjust curves.

Michèle D.

Posted: Tue Nov 16, 2004 1:07 pm
by HaraldHeim
mdessureault wrote:My photo is a more than 2M TIFF image and I am on dialup. So, I have to think about what I will do to send it to you.


Better save it as a JPG file and send the JPG to me. If necessary you can also reduce the image size if the JPG gets too large, too.


The slight blue overcast in the highlights is AFTER sampling a small area that should be white. I am familiar with the white point technique and I am happy I can use it with your(?) plug-in. Now, with another area, too much red.


Oh, I see. The blue cast in the highlights is created by ColorWasher. You have different possibilities in this case. Try another Cast Type, use the Highlights slider (I guess you already tried that) or use the Adjust slider. You can also try to sample another area or try the Auto buttons.

But as I said if I had the image it would be easier for me to give you precise instructions on how to solve that problem.

Posted: Wed Nov 17, 2004 6:27 pm
by HaraldHeim
Thanks for sending me the photo:

Image


This is a bit problematic photo, because it contains two light sources: the blueish light from the sky and the orange light from the street lamps.

You could have three onjctives for color correcting this photo:

1. Remove the blue cast and emphasize the orange color mood more.

2. Remove the orange light and emphasize the blueish day light more

3. Remove the blue cast as well as the orange cast.

Personally I would prefer 1. That can be achieved as you said by sampling the white T-shirt, but you can also use the grey ground or the walls.

The second aim can be relaized by sampling an orang window or orange lightened wall area. Orange casts are quite difficult to remove and in several cases it isn't possible without degrading the image. Anyway, I would recommend in this case to weaken the correction by setting the Adjust slider to -50 to get a more natural look.

Objective Nr. 3 is the most difficult and may make the photo look less natural. Anyway, to do that you need to create a selection for the blue as well orange lightened area and apply ColorWasher to each of the two image areas seeprately.

I hope these comments help.

Posted: Wed Nov 17, 2004 11:09 pm
by mdessureault
Hi Harald,

Yes this helps. I also prefer case 1. It looks more natural, more 'end of the day'.

Thank you :) .

Michèle D.