Topic: Awful sodium lights in a church - real help needed

[themightyzog]

Hi, I think it is a great idea to see if people can improve on an image - this one badly needs it

- if there is no image, then my Orange ISP is now yet again!
Thanks
Chris

[Greg Groess]

here is my swing at it..

[Barry Pettinger]

Looks good Greg, would you please explain to us what you did to achieve the effect.
          Thanks
          Barry

[Greg Groess]

It Looks too green now...difference between PC and Laptop I guess..
I have not done a gamma and color correction on the laptop yet. <new toy>
Sorry I should have done that...<slaps forehead>
Ok for the record...

I used LAB.
I brought in the curves to increase the contrast. 
Then I took the wall with the window as a temporary neutral. 
sounds odd but hang with me. 
The wall got rid of most of the color cast.
closed the curvemeister accepting my changes. 
re-opened it and started from where I left off.

I then went in to A and set a marker at the middle and about 1/2 way to the next grid line to give me a "pivot point" so that any changes to the green would not shift the magenta too much.  I tried then to make the leaves look good. not too over saturated but ok.

I went to the B channel and did the same thing for the yellow side. created a pivot point and adjusted the blue.  When I got the tone of the chair better I backed off a little. 

I used the saturation slider to up the saturation.

Greg

[themightyzog]

That is excellent Greg,
I had tried, but always had too much blue in it
Considering most people said one could never correct Sodium lights, I am very impressed.
Perhaps I'll dig harder and find something worse for you one day!
Thank you
Chris

[Barry Pettinger]

Thanks Greg, I tried your method, got close, but no prize.  Will keep trying.
            Barry

[BBushe]

well, reading all those LAB books drove something home...sometimes you can try RGB 

I'm in a hotel in Sweden, and as you can see I didn't even have curvemister installed on my laptop, which is also unclaibrated so I may be sending you an alien file here. I thought using multiple neutrals might help me, so I also used one on the wall, to the left, and found one that felt ok inside one of the flowers. them bumped up the green channel for the leaves. Left a decided cast on the walls above the flowers. First attachment

I tried to bump the image and remove the cast in he upper wall with LAB, think I introduced other problems. attachment in next post. I think I'll try HSB as the second step. But first I'm going to listen to a audio play of The Colour out of Space and probably go to sleep. Crikey, the Colour out of Space? HP Lovecraft predicted LAB the 1930's!

b

[BBushe]

plus the LAB. funny how the other picture looks different once I've posted, seems to have magenta than I thought.

found out why i couldn't attach two files, this one was too big.

[curvemeister]

Particularly good interpretations from others.  Here's my interpretation of this rather interesting image.  I used an initial pass in Lab mode to get rid of the overall color cast, and to get the leaves between green and yellow on the hue clock.  A second pass in RGB to get rid of the resulting blue shadows and highlights. 

Several of the previous images suffer from a cyan cast in the very bright areas.  This is a common problem in RGB mode, and one way to deal with it is a separate pass in RGB mode to tune up the highlights.  In this case, more drastic action was necessary.  I duped to a new layer, used the sponge tool to get rid of the last bit of color cast remaining in the highlights on the wall above the flowers,  and then used the blend if sliders to get rid of the cast on the wall, while retaining color in the stained glass.  The slightly strange stained glass remains a defect in my image.

This was followed by one last pass in RGB to increase the overall brightness using the RGB composite curve to bump both brightness and color at the same time.

By no means is this the final word in how this image might be corrected, and in fact I rather like BBushe's about as well as mine because there is more detail in the darker parts of the leaves.

Mike

[ianbowie]

Hi,
As a newbie doing the course...... I thought I would have a try.......

Added a photofilter adjustment layer chosing the reversed a and b values from a colour sample taken from the "white flowers" and adjusted the opasity to get rid of most of the colour cast.

Added an S curve to the lightness channel to provide more contrast in the leaves.

Minor adjustments to the yellow and green in a and b.

I think Mike's is better...... but its another approach.

Ian

[curvemeister]

Not bad Ian.  Watch that highlight detail, though, and try to get something more like Greg Groess or BBushe's.  The highlights on this image will tend to wash out unless you keep the upper part of the Lightness or RGB curve steep. - Mike

[BOS]

Hi,

Noise reduction in noise ninja
A quick try to correct the image (cant recal all the moves - just went at it.
Sodium light has a very uneven spectrum, so I used RGB in Two turns with very "spiky" curves to balance the image using various parts of the image as reference points
An extra go just over the flowers and some areas of the image to manage the blue cast.
some selective colour correction in the chair and window
adjusting contrast and saturation in HSB

Regards
Björn-Olof

[themightyzog]

That is really excellent - the walls could be a bit more sandstone - but it has completely rescued the image.

Now my challenge is to see if I can get anywhere near what you did

Thank you
Chris

[BOS]

Thank you for your kind words.
It was indeed a nice challenge.
I'm sorry that I did not record my "moves" more properly

Regards

Björn-Olof