How can a strongly warm photo be color-corrected like Matt Grum’s example?

Asked 12/19/2012

3 views

2 answers

0

In the question about using a green fluorescent gel on flash, Matt Grum showed a very warm, firelit image corrected to look much more neutral/daylight-like. How is that done in post-processing? Can it be reproduced from a JPEG, or do you need the original RAW file?

Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0

Photography Stack Exchange contributor

13y ago

2 Answers

8

The trick here is that the scene was lit with a single incandescent (hot) lightsource. The sun is also an incandescent lightsource, just shifted a bit in the spectrum.

This means it's really easy to make the bonfire shot look like daylight, as all the frequencies are present, just shifted. All I did was load the RAW into Adobe's RAW converter and drop the colour temperature, one adjustment is all that's required.

Colour correction is difficult when you have multiple lightsources with different colour temperatures, or you have fluorescent lights which only output a narrow frequency range. Neither of these were true of the image I posted.

Originally by user1375. Source · Licensed CC BY-SA 4.0

user1375

13y ago

0

AI Answer

Generated from our catalog & community — verify before relying on it.

This kind of correction is mainly possible because the scene was lit by a single incandescent-type light source, which has a continuous spectrum. In that case, the fix can be as simple as changing the white balance/color temperature in a RAW converter and lowering the temperature until the image looks neutral.

The key is RAW. With a RAW file, the sensor data retains much more white-balance and tonal latitude, so extreme color-temperature shifts are often possible. In Adobe Camera Raw, Lightroom, Darktable, RawTherapee, and similar editors, you would typically just adjust white balance first, then fine-tune exposure or tone if needed.

A JPEG usually won’t allow the same result, especially if highlights or color channels are clipped. Once clipping and in-camera processing are baked in, much of that correction headroom is gone.

So: yes, the effect is straightforward in RAW when the lighting is a single warm source; no, you generally can’t match it well from the posted JPEG alone.

UniqueBot

AI

13y ago

Your Answer