Question about the histogram

[JimHess]

I still use LrC quite a bit, but I don't participate in the forums much anymore. Found that I was giving too many incorrect replies. However, I have a question about the histogram. I've noticed that lately all of my images  have a significant white overlay over them that I haven't noticed previously. Is this new, or is there an anomaly in my installation? Just curious.

[Conrad_C · Accepted solution]

The Adobe help article Adjust the tonal scale using the histogram says (bold formatting is mine):

A histogram is made up of three layers of color that represent the Red, Green, and Blue color channels. Gray appears when all three channels overlap; yellow, magenta, and cyan appear when two of the RGB channels overlap (yellow equals the Red + Green channels, magenta equals the Red + Blue channels, and cyan equals the Green + Blue channels).

So if an area of the histogram is gray, all three channels occupy that tonal level.

[Rob_Cullen · Accepted solution]

It shows the individual three channels— red, green and blue— (all overlapping each other) as well as a white graph showing the overall luminance (or brightness).

Information gleaned from "The Missing FAQ" by the Lightroom Queen

https://www.lightroomqueen.com/

[johnrellis]

"Gray appears when all three channels overlap; yellow, magenta, and cyan appear when two of the RGB channels overlap (yellow equals the Red + Green channels, magenta equals the Red + Blue channels, and cyan equals the Green + Blue channels)."

That documentation is out of date and incorrect. The histogram changed in LR 13.0 and 13.1 and now uses semi-transparency and lines to indicate where the different channels overlap:

[johnrellis]

@Rikk Flohr: Photography, perhaps alert the documentation team that the section on the histogram wasn't updated after the changes in LR 13.0 and 13.1:

https://helpx.adobe.com/lightroom-classic/help/image-tone-color.html#adjust_images_using_the_histogr...

[Rikk Flohr: Photography]

I've alerted the Documentation team to review this article and the screenshots.

[DaveR1948]

As of Feb 10, 2025, the Adobe documentation has not been corrected yet.  See the attached Word doc.