# Histogram triangles



## russellsnr (Feb 12, 2012)

*2X Questions. Histogram triangles + Camera Profiles*

Hi, I have watched online tuts and a DVd tut on L/R and have noticed that the histogram triangles are not always Black and the presenter/s say "OK I am happy with that", my understanding is that to have a good exposure both these triangles should just be at Black. If either is not Black then the image has cliping on the H/L or Shaddow region, is this correct please?
Rather than start another topic my second question is "Do you make camera profiles"? If yes do you make a profile for each lens in differant situations ie Cloudy,sunny or overcast or make them as the occasion requires?
Many Thanks
Russ


----------



## erro (Feb 12, 2012)

If clipping is good or not for a photo is highly individual. In some photos it is impossible to avoid clipping. So there is no universal truth saying that all images should avoid clipping at all costs.

If a triangle is "toned down" it means there is no clipping.
If a triangle is "highlighted" it means there is cliping in all three RGB-channels (red/green/blue), menaing the clipped part is either pitch black or blown-out white
If a triangle is a color it means that color is clipping. Blue color indicates the blue channel, cyan color indicates both blue and green are clipping and so on.


----------



## Mark Sirota (Feb 13, 2012)

It's hard to speak in general terms as it depends on the photo and on your taste and vision.

My own opinion is that most photos benefit from having some true black, and specular highlights should usually be blown.

I have made camera profiles, but only in very specific circumstances where I was striving for a particular look.  In general I'm happy with Adobe Standard and/or the camera-matching profiles.


----------



## JimHess43 (Feb 13, 2012)

I think the OP has a slight misunderstanding of how the triangles work.  The one on the left is supposed to be black because it is to allow viewing clipping of the shadows and dark areas of the image.  The one on the right key is to allow viewing clipping of the highlights.  If you hover the mouse over the black triangle on the left then the shadows that are clipped will show with a blue color.  If you hover over the white triangle then the highlights that are clipped will show in red.  If you click on those triangles or press Ctrl/Cmd-J those triangles will become highlighted and the clipped areas will always display in the image.  But those triangles themselves will not change colors.


----------



## Mark Sirota (Feb 13, 2012)

Jim, not true.  The triangles do change color according to what is being clipped.  If nothing is clipped, they are dark; if all three channels are clipped, they are white.  If only one or two channels are clipped, they are colored appropriately like the histogram itself.

For example, see the screen shot in the first post in this thread.


----------



## russellsnr (Feb 13, 2012)

OK guys many thanks for the replies. I think I understand now that as long as they are not blown out on shaddows or highlights to an extreme amount then the colour of the photograph should be in the ball park although specular highlights may give a false reading to the true highlights in the photograph.
Please correct me if I have this wrong
Thanks
Russ


----------



## JimHess43 (Feb 13, 2012)

Well, I'm having a senior moment.  It is simply the J key that you press to view the clipping.  But I have a question. Are you referring to Lightroom on a Mac?  Because on my Windows 7 computers the triangle itself does not change colors.  So now I'm confused.  And, yes, I just checked it again to verify.

And I just looked at the screen shot in the first message.  The triangles THEMSELVES are not in a different color.  They are in the normal black on the left and white on the right.  Notice that I am talking about the triangles in the histogram.


----------



## Hal P Anderson (Feb 13, 2012)

Jim,

Sorry, but it changes colour on Win 7 as well:



Hal


----------



## Mark Sirota (Feb 13, 2012)

Jim, the left triangle is dark because nothing is clipped at the low end.  See how the histogram is not up against the left edge?  The triangle on the right is white because all three channels are clipped somewhere.  See how the histogram actually touches the right edge?

Try dragging the histogram left or right and watch the triangles change color.  (If this isn't happening on Windows, it's a bug that should be reported.)


----------



## JimHess43 (Feb 13, 2012)

I have been using Lightroom since late version 1.  I have never seen the triangles change colors.  I didn't know that was a feature.  It never has been on any of the computers I have used Lightroom with.  Is it a bug?  I don't know.  It's just nothing that I have ever seen or relied on.

Maybe I just don't have a very sophisticated graphics card.  I know I don't have anything special.  I have tried everything I can to make those triangles change colors, and they just won't do it.  Sorry guys, I stand corrected.  I guess it's better to just keep to myself.  Will do from now on.


----------



## Hal P Anderson (Feb 13, 2012)

Jim,

No problem. You went with what you had experienced and that's all any of us can do.  Don't give up trying to help--your posts have been generally good, and this can be a tough audience. 

Try very slowly increasing exposure so that one channel clips before the rest. You'll see. You may have to choose your image carefully. One with vibrant colours might be a good choice.

Hal


----------



## erro (Feb 13, 2012)

russellsnr said:


> OK guys many thanks for the replies. I think I understand now that as long as they are not blown out on shaddows or highlights to an extreme amount then the colour of the photograph should be in the ball park although specular highlights may give a false reading to the true highlights in the photograph.
> Please correct me if I have this wrong
> Thanks
> Russ



Well, the "colour of the photograph" isn't really related to the histogram. At least not as simple as a relation to the white clipping point. White balance is what controls the overall color of the photo.

What the histogram shows you is the brighness of the photo.

A specular highlight that shows as pure white (clipped/blown in all three channels) doesn't necessarily have to be white in real life. It could be a pink neon light that is so overexposed that it has saturated all three channels.


----------



## b_gossweiler (Feb 14, 2012)

Jim,



JimHess43 said:


> Maybe I just don't have a very sophisticated graphics card.  I know I don't have anything special.  I have tried everything I can to make those triangles change colors, and they just won't do it.



The effect is easier to see on an image with only a few colors in it. Try importing the following image, increase exposure and watch the triangle while each of the histogram spikes disappears to the right:




JimHess43 said:


> Sorry guys, I stand corrected.  I guess it's better to just keep to myself.  Will do from now on.


No problem, Jim, all of us are wrong/off at some point of time. I've enjoyed your contributions here and hope a can continue to do so in the future 

Beat


----------

