RGB histograms - key to good colors and contrast

[Romy Ocon]

Most birding scenes have true blacks and true whites (except perhaps those taken in foggy/hazy conditions). The key to good colors and contrast is to fill up fully the 0 - 255 values of each color channel (Red, Green and Blue), resulting into the presence of true blacks and whites in the photo.

The main tools in PS that can adjust the blacks, whites and midtone levels are the Levels and Curves tools, and to a lesser degree the Brightness/Contrast and other minor tools.


Here's a graphical example of the effects of the absence of true blacks and/or true whites on colors and contrast.

[Mark Itol]

Thanks for sharing, Ka Mastah.

By the way I've been stuck with this dilemma lately: Is there a way for PS to warn you (on a per-channel basis) if your histogram lacks true blacks or whites? What I currently do is scan each level on both sides manually and check if there is one level with no pixels in it, which is kinda time-consuming. I don't fully trust what I just see on the histogram panels as there are cases where it looks like there are no pixels on a particular level but when you hover your mouse cursor you'll find that there are indeed pixels. I've tried fiddling around the menus but I can't seem to find it.

[Eric Patdu]

Thanks for this topic Sir Romy. Will try to research more on how to use the Levels and Curves tool to aid me in processing my images.

[Bobby Kintanar]

Excellent post! This is something most of us need to do to improve our photos! Thanks Ka Mastah! :-)

[ppaaoolloo]

I agree with you Romy. Aperture also has the Levels and Curves tools as does LightRoom I believe. I will endeavor to integrate this into my workflow.

[Edu Lorenzo Jr]

I see now.. that I should really keep track of the histogram while processing. With just the photos alone I can't see the diff!

[Romy Ocon]

Aug 19, 2010 13:33:42 GMT Edu Lorenzo Jr said:

I see now.. that I should really keep track of the histogram while processing. With just the photos alone I can't see the diff!

The RGB histogram window should always be open when one is processing so one can see the effect of each adjustment, especially when highlights get blown. This is particularly true when using a less capable display (or even an uncalibrated one) which won't show accurate colors and tones. The histograms won't lie and would appear the same whether the LCD display is accurate or not.

A second LCD display, even a cheapo 15-incher, can be a very good parking area of the histogram and other windows during processing.

[Edu Lorenzo Jr]

mastah, is this an absolute must? have you encountered a picture that did not need to have both true blacks and true whites?

also, can one get away with only one? i mean only with a true black OR a true white alone?

thanks in advance!

[Romy Ocon]

Aug 19, 2010 22:53:41 GMT Edu Lorenzo Jr said:

mastah, is this an absolute must? have you encountered a picture that did not need to have both true blacks and true whites?

also, can one get away with only one? i mean only with a true black OR a true white alone?

thanks in advance!

Well, I'd say most bird photos should have true blacks (plumage or shadows) and true whites (plumage or specular highlights). The only exceptions are those taken in flat lighting, like in fog, and one wishes to preserve the flat look.

Without true blacks and whites, the photo will appear flat as far as colors and tones are concerned. Of course, if that's the way the photographer wants to present his image, then so be it.

[Edu Lorenzo Jr]

I was in the exact situation yesterday morning. The valenzuela "swamp" had a light mist about 15feet high and I was thinking "why would anyone want to shoot pics in this situation?"
Then I had a chat with another birdnut in the evening and he said "there is no such thing as bad lighting for a bird photographer.

Now I am digging the shots I took yesterday to see if I was able to nail those flying black bitterns and get that imprisoned birdnut really jealous hehehe...