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I was taking some images and experimenting with the ETTR approach. I was trying to take pictures with the exposure setting that would have the right end of the histogram just touching the border on the right. But the histogram shown in DSLR and the one of the same image in Lightroom seem to be different in terms of whether the rightmost end is touching the border or not.

Is this normal? Why does it happen? Which one is more accurate?

I used a Nikon d5600. Also, i am shooting in RAW, if that makes a difference.
Also i am not talking about the LR histogram after making adjustments. That would obviously be different. I am talking about the in camera histogram vs the histogram in LR BEFORE making any LR adjustments

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  • Lightroom's histogram seems to be the current JPEG conversion. At least if I move the sliders in the develop window the histogram changes. Sep 6, 2021 at 0:22
  • @RossMillikan I know that, but that is not the issue, s ince i am looking at the histograms BEFORE having made any adjustments yet, Sep 6, 2021 at 4:27
  • It seems on might assume the histograms give the distribution of raw data, which would not change with adjustments. The histograms before the shot would be the raw data taken from reading the sensor. This shows they are not. Sep 6, 2021 at 14:17

4 Answers 4

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There are many reasons why they may be different.

  • Many cameras will show luminance histogram clipping if any one of the color channels is clipped.
  • Many cameras will show a color channel as clipped at a level of around 245-250 (i.e. early).
  • Some camera's histograms just lie pretty badly (my D800 did)...
  • The camera's histogram is based on the camera processed jpeg and is highly unlikely to match the raw file data (if recording/editing raw).

The histogram in LR is almost certainly more accurate than the one in your camera.


Edit

And interestingly, LR's histogram may not match the camera's histogram for a jpeg image either (reasons 1-3 above).

Here is a D850 jpeg image review on the camera.

enter image description here

It shows all three channels and the combined luminance as touching the right side (clipping) and the highlight warning shows a large area on the upper chest as clipped for all four (R/G/B/L).

enter image description here

This is the same jpeg w/o any edits in LR.

enter image description here

The histogram doesn't show any luminance clipping (short of right edge), and if I hold alt while selecting the exposure slider it shows me that the small clipping warnings are for the blue channel only.

And the raw file histogram looks somewhat different as well (as expected). You can do some things so that the camera histogram(s) and image review more closely matches the raw file histogram(s); at the expense of less usable jpegs SOOC. I use the "neutral" camera profile with reduced contrast (minimum) and brightness (-1) settings so the image review is closer to a raw image in LR with the same "neutral" profile applied. You can also go down the path of using uni-wb in camera; for totally useless jpegs, a lot of hassle, and a bit better histogram match.

But none of that is absolutely necessary... all you really need is to develop a good idea of the difference between what your camera typically shows vs the same raw/jpeg file opened with defaults (and it's highlight recoverability).


Many who shoot ETTR record raw files; push the in-camera histogram to where it is just showing clipping (slightly climbing right side; at least touching), and rely on the ~1stop of recovery capability. But you have to experiment with your camera to know how far you can push it. Also, do not ETTR by increasing the ISO... there's no point to doing that (ISO is not light/exposure/data).

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  • " The camera's histogram is based on the camera processed jpeg and is highly unlikely to match the raw file data (if recording/editing raw). " If this is true, then indeed it seems like the camera histogram is less accurate than the one in LR. Sep 5, 2021 at 17:16
  • The camera's jpg is based on what you set in-camera before taking the photo. The one in Lr is a total guess. That, in my book, makes the camera's more accurate than Lr's.
    – Tetsujin
    Sep 5, 2021 at 17:53
  • @silverrahul Neither is necessarily more or less accurate than the other. They just reflect the results of two different interpretations of the same raw data. Neither is a representation of the linear, unprocessed values in the raw file. Both are representations of the raw data converted to one of a near countless number of possible interpretations of the raw data.
    – Michael C
    Sep 5, 2021 at 18:14
  • @MichaelC okay, so when i am trying to use the histogram as a guide to avoid highlight clipping, which one should i follow ? Surely from what you are saying, the LR histogram is a more accurate guide for this purpose ? Sep 5, 2021 at 18:22
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    @MichaelC " if you can see the LR histogram while you're shooting, then by all means use it to adjust exposure " I can see it , i am shooting tethered. " But it will only be more accurate if you've already adjusted LR to your final desired settings, because when you make an adjustment in LR, that change is reflected in the histogram LR " Shouldn't this be the other way round ? Shouldnt it be more accurate when i HAVEN'T made any adjustments ? Once i make adjustments, the histogram would change to reflect those adjustments. Sep 6, 2021 at 4:24
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Is this normal?

Yes, this is to be expected.

Why does it happen?

The JPEG preview image produced by the camera (when saving raw data) is one among a near countless possible interpretations of the raw data. The in-camera histogram is based upon the JPEG preview.

The image displayed on your screen when LR opens a raw file is one among a near countless possible interpretations of the raw data. The histogram displayed by LR is based on the current processed interpretation of the raw data that is displayed on your monitor.

They're not the same interpretation, therefore they won't have the same histogram.

Which one is more accurate?

Neither is necessarily more or less accurate than the other. They just reflect the results of two different interpretations of the same raw data. Neither is a representation of the linear, unprocessed values in the raw file. Both are representations of two different interpretations among a near countless number of possible interpretations of the raw data.

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  • Cameras display histograms in Live View when there is no Jpg. Sep 6, 2021 at 19:43
  • @BobMacaroniMcStevens the histogram is not actually based on the JPEG, it's based on the currently displayed bitmap, from whatever source.
    – ths
    Sep 8, 2021 at 17:09
  • The vast majority of cameras display histograms in LV that are based on what a JPEG produced from the current settings would look like. The distinction is immaterial when talking about still images that have already been shot.
    – Michael C
    Sep 8, 2021 at 18:58
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They're both "correct" for a given value of "correct".

The one in the camera knows the formula of the conversion between the RAW file & the presented image. Lightroom has only guesswork, a reverse-engineered interpretation of what Nikon intended for those settings on that RAW file.

So, both are 'correct' but each is measuring something different.

If you want to see what Nikon thinks it ought to look like, use ViewNX-i or the newer NX Studio.

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  • 1
    The one in LR is based upon the settings that result in the interpretation of the raw data currently displayed on the screen. It's not based upon any guess about what the histogram of a Nikon in-camera jpeg looks like (unless one has opened an in-camera produced JPEG in LR). The one in the camera is based upon either the JPEG (if the image was saved as JPEG) or JPEG preview (if the raw file was saved).
    – Michael C
    Sep 5, 2021 at 18:10
  • @MichaelC - so, it's based on guesswork, as I said, not upon anything decided by the photographer in-camera. I doubt we will ever agree on this, but I simply hate what Lr does to my photos. I just will not use it, precisely because of that.
    – Tetsujin
    Sep 5, 2021 at 18:31
  • It's not based on any amount of guesswork. Both histograms are based upon a specific interpretation: The one that is currently being displayed, either on the camera's display or on the computer's display.
    – Michael C
    Sep 5, 2021 at 18:39
  • @MichaelC - the image itself is total guesswork, so the histogram is relevant only to that poor interpretation of what the camera was set to. That makes it less use than a chocolate fireplace, imo.
    – Tetsujin
    Sep 5, 2021 at 18:41
  • The histogram is not the image, it is an empirical representation of an image. The image may be a guess as to what the photographer ultimately wants to end up with (which can be just as true for the in-camera JPEG preview as it is for the initial interpretation displayed by LR), but the histogram is not a guess about the brightness levels of whatever the displayed image looks like. You seem to be arguing that the only possible "correct" image from a raw file is the JPEG preview produced in camera. If that is the case, then why not just save straight to JPEG and do no further editing at all?
    – Michael C
    Sep 5, 2021 at 18:46
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A histogram displays the frequency at which values fall into an arbitrary set of ranges.

Arbitrary in the sense that two histograms of the same data can divide a range possible values into a different quantity of ranges.

For example, one histogram might divide the possible values of the blue channel into 10 ranges and another might divide the same possible values into 100 ranges.

How many ranges to use is entirely dependent on intent. Lightroom’s histogram cannot prevent over exposure (tethering excepted). It is too late. The camera histogram cannot prevent clipping in post processing (in-camera edits excepted). It is too soon.

Ultimately, the photographer just has to learn from experience what the histogram in each tool means.

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  • " Lightroom’s histogram cannot prevent over exposure (tethering excepted). " Interesting, you should mention that. I WAS using tethering with laptop. This is why i had the option to compare both the histograms as soon as i took the capture and noticed the difference. Sep 6, 2021 at 4:16

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