Correcting white balance setting

[dalle]

Hi,

I have taken several shots using my A40 in P mode using the wrong setting for the White Balance, e.g. Tungsten when it should have been Daylight.

Now, I am looking for an easy way to correct this, i.e. un-apply the Tungsten WB and apply the Daylight WB correction, but unsuccesfully. I tried Zoombrowser, the BreezeBrowser mentioned in some of the forums here, Paint Shop, and others, but there a lot of trial-and-error seems necessary.

Is there no standard color scheme correction parameters for the standard WB settings in the A40 (and others) and (simply) way to reverse the effect?

Hans.

[robekert]

What format are you shooting in, RAW or JPEG? If it is JPEG, which I suspect you are, you have less of, or no chance of changing the white balance.
Rob

[dalle]

Yes, the A40 only allows storing as JPG. But I suppose there must be some formula applied for the WB correction which can be reversed(?)

Hans.

[Leighow]

I do not know the profesional answer to this question, but I can give you my 2 cents. Last year I shot a 32 meg "clip" outdoors before dusk in waining sunlight, but on the tungsten by mistake ! While I liked them as tshot, the were (not unexpectedly) heavy blue/cyan. Here is how I altered the shots in PS:

1: I brightned to taste.
2: I added a fair amount of yellow to the color balance and a touch of both red and blue
4: I adujusted the blue and cyan hues -- basically darkening or lightening them to taste.

Are these shots equal to "daylight" shots ? I doubt it, but they reasonable.

Why not post a sample and I will convert it as described.

HOWIE

[dalle]

Thanks for the suggestions. I tried it a bit, but then I found this link

http://www.geocities.com/lasm.rm/wb1.html

which points towards a more deterministic approach. I think I'll make some experiments to map out the exact parameters for the necessary corrections.

Hans.

[Wildman]

While your camera doesn't give you the capability, it clearly points out the advantage of shooting using the Canon RAW mode when available.

White balance is absolutely critical to getting the color right. My Canon Pro90 (and many other cameras) can sample from a card in the existing light, a really nice feature.

BTW, I bought a Canon A40 for my daughter. It's a terrific camera, but does lack some advanced features.

[dtrayers]

If you have Photoshop Elements (you can download a free trail from Adobe), there is an enhancement tool to correct for color cast. It might not get your picture all the way there, but it might be close enough for some minor tweaking.

With the tool, you click on something in you picture that "should" be white, grey or black (neutral). The rest of the picture should respond accordingly.


FWIW...