Lightroom Clipping Indicators

[Ellis Vener]

Just discovered something I had not noticed before in Lightroom's histogram: even without turning on the boxes around the clipping indicators ( keystroke : J) the clipping point triangles will light up to let you know there is clipping somewhere in the photo.

[kaelaria]

That's the entire point of them being there.

[Ellis Vener]

Yes kaelaria, but not everyone knows this. In fact I have been surprised by the number of people I know who have been using Lr for a couple of years who were unaware of it. Not everyone is as expert a user as you are.

[kaelaria]

No need for the snaky remarks, I'm just stating a fact.

[fdisilvestro]

The nice thing is that the color of the triangle shows which channel is clipping. When the color is white, then all channels are clipping.

[Ellis Vener]

Great point Francisco!

[donbga]

Great point Francisco!

I'm sure Kaelaria was about to mention that!

[digitaldog]

Only issue is the clipping isn’t based on what you’ll end up after you render the data unlike ACR. Its Melissa RGB.

[Guillermo Luijk]

Only issue is the clipping isn’t based on what you’ll end up after you render the data unlike ACR. Its Melissa RGB.

Now everyone should say: ohhhhhhhhhhhhhhhhhhhhhhhh 

[fdisilvestro]

The clipping points will be the same for ProPhotoRGB

[digitaldog]

The clipping points will be the same for ProPhotoRGB

For the primaries yes, but its using a totally different gamma encoding so it isn’t going to be the same and, if you are not using ProPhoto, its going to be even farther off.

[fdisilvestro]

Gamma encoding will change the shape of the histogram but will not affect the extreme values. At the maximum signal level of 255 (assuming 8 bits) the value is the same, it is where the linear and gamma curve intersect, so there is no way to alter the clipping point by gamma encoding.


If you use any other color space, then I agree with you.

[digitaldog]

Gamma encoding will change the shape of the histogram but will not affect the extreme values. At the maximum signal level of 255 (assuming 8 bits) the value is the same, it is where the linear and gamma curve intersect, so there is no way to alter the clipping point by gamma encoding.

Well I haven’t tested it, maybe you have. I’d be surprised if an sRGB TRC which is what MelissaRGB is showing is the same in the darker areas as a 1.8 true gamma curve of ProPhoto RGB. I don’t think it will be much, point is, unlike ACR, we are not getting the proper (ideal) feedback.

[madmanchan]

The clipping point as indicated by the triangles is minimally affected by gamma encoding choices.  This is because of rounding.  Effectively, we apply a gamma encoding and then see what round up to 255 and what round down to 0 (i.e., 8-bit rounding).  The choice of gamma value will affect values just at that threshold.  Not worth worrying about, but just FYI in case you wonder why.

[Guillermo Luijk]

Eric, the one million euro question is: why Adobe decided not to adapt the histogram to the chosen output colour profile like ACR does?

[madmanchan]

Alas, the choice of output profile in LR is not as clear cut as in ACR.  That is, in LR the output paths are Export, Print, and Web (and Publish, I suppose). Even if one were to focus on just one of these (e.g., Export) it is possible to have many export templates set up (with different choices of color space).  Hence it's not clear which one to use.  Using the "last Export template used" would be inconsistent and confusing, since it could vary over time, even within one LR session.

To be honest, I don't think checking for clipping via histograms (even if the user gets to choose the color space) is particularly useful.  I understand it's the only way available currently, but we need a better way in the future.

[fdisilvestro]

Maybe a nice way could be softproofing with destination space histogram

[digitaldog]

I agree its not as clear cut as ACR but it wouldn’t be that difficult IMHO, to just allow the user to option click on the Histogram and call up a list of profiles as we see in print (filtered such that you can limit the list). It doesn’t have to sync with the other modules, only the Histogram and associated RGB percentage values (with perhaps, the ability to set the scale to 0-255). What happens in other modules isn’t important, no histogram or numbers to deal with. Let Web deal in sRGB.

Doing this would at least allow parity with ACR. In fact it would provide more options which might be an ACR issue. With the option for scale, at least a user could see the same values in LR as they get in Photoshop or would see in ACR. Then I’d want to see Photoshop provide the percentage options for its info palette. I actually prefer, and find many newer users learn dealing with the numbers as percentages easier than 0-255.

[David Eichler]

Hope this isn't getting off topic, but I see the highlight clipping indicator change when adjusting the brightness slider. I thought the brightness control was not supposed to affect the extremes. Or, is the clipping indicator not accurate in this regard. Maybe this has to do with the rounding?

[Scott Hargis]

My understanding of the clipping indicators is that they will indicate clipping in any channel. Probably by adjusting the Brightness slider, you're pusing one channel over the limit. Saturated primary colors seem to be most susceptible to this. This is a subject I'm very interested in - someone please correct me if I'm wrong about this!