Correcting faulty white balance setting?

[bugbear]

Last night I took a hdr-panorama of my small town's christmas lights.

I set my Canon A630's white balance to be "flourescent", thinking of street lights.

Looking at the images, I'm far from sure this was correct, since there are many. MANY incandescent lights (the xmas lights!!!!).

The image looks a bit yellow to me.

So; how can I make the image more accurate (fix the mistake) or, since the only purpose of this image is to be "pretty" how can I make the image more pleasing?

(the attachment is a crop from the panorama, and I'm working on Linux, which means Gimp not Photoshop)

BugBear

[Markzebra]

Best method these days is to use the two white point sliders in Camera RAW. And make sure your monitor is calibrated. If you want to do it the old and slightly more destructive way then Selective color Whites and Neutrals

[bugbear]

Originally Posted by Markzebra

Best method these days is to use the two white point sliders in Camera RAW. And make sure your monitor is calibrated. If you want to do it the old and slightly more destructive way then Selective color Whites and Neutrals

Are those Photoshop commands?

BugBear

[mtpfamily]

Depends on what photo editing software you use. If you shoot in Raw format use the software that came with the camera and you can change the white balance. I personally have found that for pictures like that I set a white balance of 5200 to 5500.

[bugbear]

Originally Posted by mtpfamily

Depends on what photo editing software you use. If you shoot in Raw format use the software that came with the camera and you can change the white balance. I personally have found that for pictures like that I set a white balance of 5200 to 5500.

A Canon A630 is a compact, and doesn't support RAW.

BugBear

[mtpfamily]

Sorry about that if you use Cs4 it has camera raw feature that will let you play with white balance with Jpgs. You may also just take several pictures with diferant white balance settings. Try Daylight setting that is usaly a 5200-5500.

[mtpfamily]

I don't know what photo editing software you use but here is a try at fixing the yellow you wanted.
Duplicated the picture turned it black and white. Put as soft light opacity 65%
adjustment layer color balance
Mid-tones were set
Cyan-red -26
Magenta-green +16
Yellow-blue +34
Highlights
Cyan-red -10
Magenta-green 0
Yellow-blue +19
Adjustment layer
Brightness/contrast
Brightness +2
Contrast +4

[philbach]

I just put Bugbear's original and Mtp family's photos together. The question is what tint do you prefer. The warmer tint or the cooler one. So I would recommend that you adjust the "warmth" of the photo to what appeals to you most. I prefer the warmer more yellow tint. I did notice what appears to be some motion blurring in the photo

[Markzebra]

As mtp has said it doesn't matter if your camera doesn't output in a readable RAW format: You can save the image as either a high quality jpeg or a TIFF, and read this into the camera RAW dialog. Under open choose your file and then under 'format' in the long list you will see RAW. This was also the case in CS3.

For others, Camera RAW as a colour correction tool has progressed hugely. The reason its less destructive as a first step than editing directly in Photoshop is because it changes the file to a higher bit depth, using whats called 'floating point' and a wider gamut color space than standard RGB. This mostly seems to deliver a smoother less damaged result. Try it. Remember you can also have this as a RAW smart object embedded inside your photoshop document. A standard way to work now is to have varying exposures all set up as RAW objects initially.

[TommyO]

bugbear,
Everyone is giving good advise, only they didn't read you use Linux and Gimp only.

I don't use Gimp, so I can only steer you in a direction. Look for an adjustment that allows you to set a white point and a black point (mostly interested in the white point for this image). Then experiment... find a very small point that really should be white and click on that with the white point tool. You may have to adjust the levels/histogram slightly afterward to your taste.

As the others mentioned, you will find a third party RAW converter/editor a big plus for images like this one. When no real adjustments other than color are required, they are hard to beat. Plus they edit less destructively.