Question about temperature

[Jmurman]

I saw a night photo from someone who said that he used 4000 degrees as his color temp. What does that mean? The photo was very impressive for sure. Can I do that with my 300D?

[Roach711]

If you shoot RAW you can use the Photoshops Camera RAW plugin to change the color temperature of the shot to remove color casts.

[hmhm]

There's some info here:
http://www.dpreview.com/learn/?/Glossary/Digital_Imaging/White_Balance_01.htm

The basic idea comes from "black body radiation" in physics. If you heat an object to a high temperature, it will emit a spectrum of light (think of a hunk of metal heated until it starts to glow red). As you raise the temperature of the object, that spectrum shifts towards the blue end.

Any way, it's just a quantitative way of describing the color of an "ideal" light source (one with a nice, evenly spread spectrum that looks like a bell curve), for use in setting white balance.

The 300d doesn't seem to support setting white balance via color temperature, though the higher-end Canon DSLRs do (including the 10D). On the 300D you can choose from among the standard "presets" or use the custom white balance feature.
-harry

[PhotosGuy]

This is a good link, too:
http://www.webphotoschool.com/newschool/freelessons/lessons/d560wbIn/index.html

You can force a WB in the 300D, too but I don’t recommend it.
For instance, 4000K is a warm, yellow color about 1500K from the “Midday Sun, Flash” ‘ideal’ WB of 5,500K. If you Custom WB with the color complementary to yellow (blue) in the 7,000K range, the cam will compensate & the result will be as if the lighting when you take the pic was at 4,000K. So, you’d have to Custom WB with a light blue card.
You can get some interesting effects doing this in the cam, but using RAW & changing WB after taking the pic gives you much more control over the finished result.

[iwatkins]

All good info above. I usually shoot RAW on the 10D so have control of this afterwards.

But I would stress to anyone who has a maybe keeper to have a go after doing all the other settings to swing the Colour Temperature about wildly in your RAW convertor before developing. You can get can some great effects and real moody shots.

Cheers

Ian

[Jmurman]

This is a good link, too:
http://www.webphotoschool.com/newschool/freelessons/lessons/d560wbIn/index.html

You can force a WB in the 300D, too but I don’t recommend it.
For instance, 4000K is a warm, yellow color about 1500K from the “Midday Sun, Flash” ‘ideal’ WB of 5,500K. If you Custom WB with the color complementary to yellow (blue) in the 7,000K range, the cam will compensate & the result will be as if the lighting when you take the pic was at 4,000K. So, you’d have to Custom WB with a light blue card.
You can get some interesting effects doing this in the cam, but using RAW & changing WB after taking the pic gives you much more control over the finished result.

OK, so how can I change my specific temperature on my RAW photos for post processing. I have PSCS and am somewhat new to it.