remove blue cast in Lightroom

Started Mar 2, 2013 | Discussions thread
b4cktr4ck
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Re: remove blue cast in Lightroom
In reply to richardplondon, Mar 4, 2013

thanks RP for the detailed explanation. I still see too much difference between the jugs (warm) and the lower shelf, I still see some blue from my monitor

richardplondon wrote:

Firstly, I don't think this is a "blue cast", in the sense that would usually apply - where a whole picture is all shifted in colour due to some process-related reason (often, white-balance). Here, the picture was apparently taken in a mix of warmish artificial light (which was brightest at the top and left of the picture), and relatively cool natural light - from a window? - which falls mainly acorss the lower and right side areas. The shelves in the middle are getting both kinds of lighting together from differnt directions - so these are shadowing differently, also affecting differently oriented surfaces differently. But they are not a long way "off" in colour, IMO.

It is up to you whether this (real) lighting context is "all part of the picture" (I personally might even have enhanced it) - or else, something that you wish to try to eradicate - or at least, to reduce in its prominence.

Assuming the latter, I would first tackle the general underexposure which goes some way to make the lower part of the picture duller than it needs to look. Also, this underexposue optically increases the contrast in lighting, since we perceive hue differences more strongly around the mid-to-light greys region, than we do around the light-greys to whites region.



as uploaded

So I started - this is, from your posted image of course, values would be different from Raw - with +1.3 Exposure using the process version 2012. This exposure lift "rolls off" the whites a bit, and also lost a little shadow definition, which I put back wth Contrast +50 - this would often be too big a value, but IMO works well here as more or less a single-slider fix. Contrast is a very clever, adaptive control in LR4 and rather under-discussed. I added a touch of crispness (as distinct from sharpening) too, with Clarity +10.

exposure +1.3, contrast +50, clarity +10

That seems to give a very different idea of the white-balance / warm and cool issue. At this point, I felt it better to regard the problem not as the cold lighting (which can be tackled with a minimal +5 temperature, so far as the generality of the picture is concerned - these kinds of surfaces "love" daylight) but instead, the rather heavy yellow lighting just at the top once this general WB correction is present. So I added a graduated filter working from top right, down toward the middle, angled suitably and applying a -8 Temperature adjustment together with a +0.22 stop Exposure increase.

+5 global Temp, -8 Temp and +0.22 Exposure graduated filter on the top-right region

It would be perfectly possible to apply a delicate second grad from the lower edge, with say a +3 Temp value, to remove the remaining impression of daylight at the bottom; but I personally would not do so. I enjoy seeing a variety of whites, with light bouncing around them in interesting ways.

regards, RP

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