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Aug 6, 2019 14:23:16   #
Silverrails
 
I am looking for some advice, explanations, definitions of a Good and proper Histogram of Digital Image. I have observed other Photography sites, but I want to hear from an expert on Histograms here at UHH.
Thanks in advance for your knowledge on this subject.

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Aug 6, 2019 14:29:53   #
via the lens Loc: Northern California, near Yosemite NP
 
There is no one correct histogram for an image. It all depends on what you are shooting and what you want your image to be in the end. If you are referring to the histogram in your camera as you shoot the idea, most often unless shooting highboy, is to capture as many tones as possible without blowing out highlights, so check that your histogram is not so far to the right that it is touching the side of the histogram; having said that, many, if not most, cameras pick up about two stops more than the histogram for a RAW image. JPEG shooters must be more careful to stay within the histogram camera boundary. Then there is the histogram that shows up in an application program. This histogram helps you to understand where a part of your image may be blown out and how many tones you have captured in your image. You would do best to read up on the subject from an expert source rather than to trust what any of us on this site tell you!

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Aug 6, 2019 14:36:56   #
rgrenaderphoto Loc: Hollywood, CA
 
The histogram is not an easy thing to understand but should be the first tool you use when composing an image. You can tell if your composition is over or underexposed, etc.

I compose an image and check to make sure that the histogram is balanced, that there are not excessive highlights (blown out) or shadows (underexposed). Some, but not all of these can be corrected in Post but blown-out highlights you are pretty much stuck with unless you take the time to analyze the histogram before clicking the shutter.

Rather than just paraphrase, watch this Tony Northrop video, where he clearly explains what the histogram is and how it is to be used:

https://www.youtube.com/watch?v=ZmAw_Zd7zP4

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Aug 6, 2019 15:05:43   #
Pepsiman Loc: New York City
 
Look for histograms on you tube. Adorama TV.

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Aug 6, 2019 15:20:20   #
rmalarz Loc: Tempe, Arizona
 
Histograms are simply a statistical tool. In the digital realm of photography, the horizontal axis is divided into 256 units. This corresponds to the tonal range associated with digital images. The vertical scale indicates how many of each tone value is present in an image.

As such, there is no "Good or proper" histogram. It's only a guide. It can assist in determining if the exposure is set correctly, but again, this is only a guide. The drawback to the histogram, especially the in-camera histogram is that it shows the values of the camera-generated jpg and not the values present in the RAW file.
--Bob

Silverrails wrote:
I am looking for some advice, explanations, definitions of a Good and proper Histogram of Digital Image. I have observed other Photography sites, but I want to hear from an expert on Histograms here at UHH.
Thanks in advance for your knowledge on this subject.

Reply
Aug 6, 2019 16:09:09   #
selmslie Loc: Fernandina Beach, FL, USA
 
Silverrails wrote:
I am looking for some advice, explanations, definitions of a Good and proper Histogram of Digital Image. I have observed other Photography sites, but I want to hear from an expert on Histograms here at UHH.
Thanks in advance for your knowledge on this subject.

There is no proper histogram in the camera. It's just an indication of roughly how much of the image you are looking at is light, dark or in-between.

You can't even rely on a histogram to tell you how close you are coming to blowing out the highlights or blocking up the shadows. Some camera brands actually come pretty close to telling you what is happening in the raw file while others show you only what is happening to the JPEG.

Some will show you the three red, green and blue channels separately in addition to the single white luminance histogram. And some cameras you can even see the luminance histogram before you trigger the shutter.

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Aug 6, 2019 16:28:44   #
Steve Perry Loc: Sylvania, Ohio
 
Everything you need to know :)

https://backcountrygallery.com/reading-understanding-histograms-photography/

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Aug 6, 2019 17:30:49   #
selmslie Loc: Fernandina Beach, FL, USA
 

That's a comprehensive explanation although "everything" may be a little overstated.

You describe what happens with Nikon and Canon cameras that use 14-bit raw files and how the highlight warnings (blinkies) relate to the histogram. Sony is almost the same.

All three offer a way to recover highlight and shadow information. Nikon calls it Active D-Lighting, Canon and Sony use a different name. They also influence the histogram because they change the JPEG.

But there are still many cameras that still use 12-bit raw files. Their histograms behave a little differently. They may represent the limitations of both the JPEG and raw data. So do their highlight warnings.

And Fuji X-Tran sensors are a little different. With my X100T (also 14-bit) the histogram and blinkies seem to track very closely to what is recorded in the raw file itself rather than the JPEG. I need to keep the histogram away from the right limit to prevent the JPEG from blowing out. In addition, Fuji has a different approach to highlight and shadow recovery for the camera's JPEG.

The only way to get a handle on everything is for the photographer to do some testing on their own camera. Since most photographers only need to consider a single camera brand, this should not take too long.

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Aug 6, 2019 17:45:02   #
CHG_CANON Loc: the Windy City
 
Silverrails wrote:
I am looking for some advice, explanations, definitions of a Good and proper Histogram of Digital Image. I have observed other Photography sites, but I want to hear from an expert on Histograms here at UHH.
Thanks in advance for your knowledge on this subject.


Any 'expert' that tells you there is such a thing as a 'good and proper' histogram clearly is not ....

I'd suggest you consider a few interrelated issues:

1) Are you shooting in RAW?
2) If you shoot JPEG, do you plan / want to edit further or do you want straight-out-of-camera (SOOC) JPEGs?
3) What is the noise profile of your camera model?

To me, the histogram has become less relevant than the highlight warning (aka blinkies). When I review test images / in-progress images, I look first at where the highlight warnings occur. If I have warnings, I know, without even looking at the histogram, the histogram will be pushed to the right edge. With extensive experience over tens of thousands of images, I know from a glace at the location of blinkies whether I can recover this highlights in post from my RAW files. If have concern, such as a close-up portrait, I'll adjust the exposure as needed to remove the highlight warnings, pulling the histogram back to the left.

Why are my three questions relevant?

As a Canon EOS RAW shooter, I want that histogram as far to the right as possible for every ISO value and I adjust the exposure in post, whether RAW or JPEG. This Expose to the Right (ETTR) approach reflects the noise profile of every EOS body I've used. For my Sony camera that has a different noise profile, I'm less 'over the edge' of the right side of the histogram, but still seeking exposures that cause some highlight warnings.

You / no one can say what a 'perfect' histogram would look like for every camera and every exposure situation. Rather, develop your own hands-on knowledge with your camera, and if applicable, your processing software.

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Aug 6, 2019 18:01:34   #
selmslie Loc: Fernandina Beach, FL, USA
 
CHG_CANON wrote:
... To me, the histogram has become less relevant than the highlight warning (aka blinkies). ....

That's what I have learned from looking at three different camera brands - Nikon, Sony and Fuji. What I have found has been confirmed by a couple of similar tests done by Canon users.

The blinkies not only tell you if you might be getting too much exposure but also where in the image that is happening (they might be flashing in an area you don't really care about).

Blown highlights can't be fixed. Noise in the shadows can usually be fixed or covered up.

I find that if shoot at the lowest practical ISO I can address the noise issue.

If I can get a decent looking JPEG from the camera then I might be able to improve on it by developing the same image from the raw file.

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Aug 6, 2019 20:30:59   #
rgrenaderphoto Loc: Hollywood, CA
 
selmslie wrote:
There is no proper histogram in the camera. It's just an indication of roughly how much of the image you are looking at is light, dark or in-between.

You can't even rely on a histogram to tell you how close you are coming to blowing out the highlights or blocking up the shadows. Some camera brands actually come pretty close to telling you what is happening in the raw file while others show you only what is happening to the JPEG.

Some will show you the three red, green and blue channels separately in addition to the single white luminance histogram. And some cameras you can even see the luminance histogram before you trigger the shutter.
There is no proper histogram in the camera. It's ... (show quote)


Seriously? Camera manufacturers spend billions on designs to display exposure data and it isn't valid?

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Aug 6, 2019 21:01:35   #
selmslie Loc: Fernandina Beach, FL, USA
 
rgrenaderphoto wrote:
Seriously? Camera manufacturers spend billions on designs to display exposure data and it isn't valid?

It means something. It’s just not as useful as other information.

What makes it “valid” for you?

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Aug 7, 2019 06:39:08   #
Tomfl101 Loc: Mount Airy, MD
 
CHG_CANON wrote:
Any 'expert' that tells you there is such a thing as a 'good and proper' histogram clearly is not ....

I'd suggest you consider a few interrelated issues:

1) Are you shooting in RAW?
2) If you shoot JPEG, do you plan / want to edit further or do you want straight-out-of-camera (SOOC) JPEGs?
3) What is the noise profile of your camera model?

To me, the histogram has become less relevant than the highlight warning (aka blinkies). When I review test images / in-progress images, I look first at where the highlight warnings occur. If I have warnings, I know, without even looking at the histogram, the histogram will be pushed to the right edge. With extensive experience over tens of thousands of images, I know from a glace at the location of blinkies whether I can recover this highlights in post from my RAW files. If have concern, such as a close-up portrait, I'll adjust the exposure as needed to remove the highlight warnings, pulling the histogram back to the left.

Why are my three questions relevant?

As a Canon EOS RAW shooter, I want that histogram as far to the right as possible for every ISO value and I adjust the exposure in post, whether RAW or JPEG. This Expose to the Right (ETTR) approach reflects the noise profile of every EOS body I've used. For my Sony camera that has a different noise profile, I'm less 'over the edge' of the right side of the histogram, but still seeking exposures that cause some highlight warnings.

You / no one can say what a 'perfect' histogram would look like for every camera and every exposure situation. Rather, develop your own hands-on knowledge with your camera, and if applicable, your processing software.
Any 'expert' that tells you there is such a thing ... (show quote)


You are absolutely right about observing the blinkies, particularly when photographing rapidly moving, changing or backlit scenes. Histograms are useful and informative but not worthy of my attention on a busy shoot. As you noted, the Histogram doesn’t tell you where the overexposure lyes within the image. Only the blinkies will do that. My advise to budding photographers is to understand them and then stop worrying about them. Learn to observe the image on-screen, make adjustments and continue shooting.

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Aug 7, 2019 08:11:44   #
geezer76 Loc: Prineville, Oregon
 



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Aug 7, 2019 08:35:06   #
Blair Shaw Jr Loc: Dunnellon,Florida
 
rgrenaderphoto wrote:
The histogram is not an easy thing to understand but should be the first tool you use when composing an image. You can tell if your composition is over or underexposed, etc.

I compose an image and check to make sure that the histogram is balanced, that there are not excessive highlights (blown out) or shadows (underexposed). Some, but not all of these can be corrected in Post but blown-out highlights you are pretty much stuck with unless you take the time to analyze the histogram before clicking the shutter.

Rather than just paraphrase, watch this Tony Northrop video, where he clearly explains what the histogram is and how it is to be used:

https://www.youtube.com/watch?v=ZmAw_Zd7zP4
The histogram is not an easy thing to understand b... (show quote)



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