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Author Topic: The Right Histogram  (Read 2252 times)

brucehughw

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The Right Histogram
« on: October 14, 2019, 06:29:32 pm »

Hello,

I received an email from LL, with this text:

The Right Histogram
The photo-histogram is probably the most ubiquitous exposure tool in digital photography, that is, short light metering itself. It has been with us more than 25 years, and it hasn’t changed much. The histograms we are familiar with are calculated from transformed data, not raw data. Understanding how that transformation affects the resulting histogram can be important. Here we look at three kinds of photo-histograms: (1) the gamma level histogram,...

Sounds promising. Trouble is I can't find it. Has anyone received this email and/or found this post? I'd like to read it. Thanks, Bruce
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josh.reichmann

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Re: The Right Histogram
« Reply #1 on: October 14, 2019, 07:18:24 pm »

Hi Bruce (and this can be a general response for others). The article required some reformatting on my end. Was published prematurely, and the author requested I fix it, which I am in the process of doing. It’s a great and useful piece.
Apologies for the psych out. It’ll hopefully be back up in the following days!

Best,

Josh
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Compassion and wisdom are inextricably linked.

digitaldog

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Re: The Right Histogram
« Reply #2 on: October 14, 2019, 08:11:09 pm »

Well there's is this.....

Everything you thought you wanted to know about Histograms

Another exhaustive 40 minute video examining:

What are histograms. In Photoshop, ACR, Lightroom.
Histograms: clipping color and tones, color spaces and color gamut.
Histogram and Photoshop’s Level’s command.
Histograms don’t tell us our images are good (examples).
Misconceptions about histograms. How they lie.
Histograms and Expose To The Right (ETTR).
Are histograms useful and if so, how?

Low rez (YouTube): http://www.youtube.com/watch?v=EjPsP4HhHhE
High rez: http://digitaldog.net/files/Histogram_Video.mov
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Andrew Rodney
Author “Color Management for Photographers"

bwana

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Re: The Right Histogram
« Reply #3 on: October 29, 2019, 10:43:22 am »

@digitaldog
I have to admire your devotion to this topic. You offer the reference to the countless people that mention histograms. Dont you ever tire of saying it? Still, it would be nice to have a calculation that permits a good guess as to the REAL histogram in the field form the thing we see in the viewfinder. Because of this uncertainty I stay a stop under the exposure where clipping highlight  indicator appears and bracket up.
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digitaldog

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Re: The Right Histogram
« Reply #4 on: October 29, 2019, 01:12:43 pm »

@digitaldog
I have to admire your devotion to this topic. You offer the reference to the countless people that mention histograms. Dont you ever tire of saying it?
When they stop asking about the facts behind Histograms, I'll get to stop explaining how they actually operate.
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Andrew Rodney
Author “Color Management for Photographers"

DP

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Re: The Right Histogram
« Reply #5 on: October 30, 2019, 10:19:55 pm »

@digitaldog
I have to admire your devotion to this topic. You offer the reference to the countless people that mention histograms. Dont you ever tire of saying it?
may be he is a bot ?
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digitaldog

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Re: The Right Histogram
« Reply #6 on: October 31, 2019, 09:29:22 am »

may be he is a bot ?
Creating the video's is the work. Pasting into about it isn't. You don't need a bot for that.
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Andrew Rodney
Author “Color Management for Photographers"

Doug Peterson

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Re: The Right Histogram
« Reply #7 on: November 05, 2019, 07:59:12 pm »

@digitaldog
I have to admire your devotion to this topic. You offer the reference to the countless people that mention histograms. Dont you ever tire of saying it? Still, it would be nice to have a calculation that permits a good guess as to the REAL histogram in the field form the thing we see in the viewfinder. Because of this uncertainty I stay a stop under the exposure where clipping highlight  indicator appears and bracket up.

You can have that today in an Phase One IQ4.

Ray Cox

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Re: The Right Histogram
« Reply #8 on: February 08, 2020, 10:18:52 pm »

I just finished reading an article that is quite in-depth. It required a bit of deep thinking and rereading, but quite interesting. Unfortunately on a competing site. So, I'll attempt to attach a link. I do believe it is worth the time exploring!

https://photopxl.com/noise-iso-and-dynamic-range-explained/?fbclid=IwAR34FMgh5KezbeWVuvEapxSwS3kwnLEVX2zbNZ6gSKn429UHwaGw8a9CdQ0
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DP

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Re: The Right Histogram
« Reply #9 on: February 09, 2020, 11:21:58 am »

I just finished reading an article that is quite in-depth. It required a bit of deep thinking and rereading, but quite interesting. Unfortunately on a competing site. So, I'll attempt to attach a link. I do believe it is worth the time exploring!

https://photopxl.com/noise-iso-and-dynamic-range-explained/?fbclid=IwAR34FMgh5KezbeWVuvEapxSwS3kwnLEVX2zbNZ6gSKn429UHwaGw8a9CdQ0

Historically the classical article is http://theory.uchicago.edu/~ejm/pix/20d/tests/noise/ from Emil Martinec from 2008 that he wrote when the previous (RIP) owner of this site alleged that it was a number of gradations available that was the whole point of ETTR... PS: that was before dual-gain sensors
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kimballistic

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Re: The Right Histogram
« Reply #10 on: February 11, 2020, 11:57:52 am »

I just finished reading an article that is quite in-depth. It required a bit of deep thinking and rereading, but quite interesting. Unfortunately on a competing site. So, I'll attempt to attach a link. I do believe it is worth the time exploring!

https://photopxl.com/noise-iso-and-dynamic-range-explained/?fbclid=IwAR34FMgh5KezbeWVuvEapxSwS3kwnLEVX2zbNZ6gSKn429UHwaGw8a9CdQ0

The folks over at DPReview's Photographic Science & Technology forum don't think too highly of it, sadly:

https://www.dpreview.com/forums/post/63617934

Historically the classical article is http://theory.uchicago.edu/~ejm/pix/20d/tests/noise/ from Emil Martinec from 2008 that he wrote when the previous (RIP) owner of this site alleged that it was a number of gradations available that was the whole point of ETTR... PS: that was before dual-gain sensors

Martinec's article on noise, DR, & bit depth is the standard by which all others should be judged.  It's just an amazing work.  It's a bummer that he has since lost interest in photography and moved on to other hobbies.  The quality and clarity of his writing is unmatched.

For what it's worth, Bill Claff of photonstophotos.net is now hosting the official copy of Martinec's article (with the author's approval).  He's been able to keep links updated and fix a few errata over the years:

http://www.photonstophotos.net/Emil%20Martinec/noise.html
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digitaldog

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Re: The Right Histogram
« Reply #11 on: February 11, 2020, 12:27:37 pm »

Iliah is one of the most knowledgeable people on this subject around, he happens to be the author of RawDigger and FastRawViewer. That’s about the only reason to venture over to the DPR forums. What he wrote is telling:

And yes, the article referenced by OP is pretty messy, and it is odd Kevin published it.
http://www.libraw.org/
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Andrew Rodney
Author “Color Management for Photographers"

kimballistic

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Re: The Right Histogram
« Reply #12 on: February 11, 2020, 12:46:52 pm »

Iliah is a great resource and definitely worth following for a no-BS perspective on issues.

But there are other heavy hitters and very solid contributors in that forum as well- Eric Fossum (!), Bill Claff, Jack Hogan, Roger Cicala, Jim Kasson (not so much in PS&T, but in the Sony/Nikon Z/Medium Format forums), and there are also a few semi-anonymous accounts owned by people clearly experienced in lens design- like for example Brandon Dube, who worked/works with LensRentals on their OLAF optical testing equipment.
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kimballistic

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Re: The Right Histogram
« Reply #13 on: February 11, 2020, 12:50:04 pm »

It might be worth linking to the article that originally started this thread.  Looks like it finally got published at PhotoPXL, not LuLa.

https://photopxl.com/a-better-histogram/

It seems to be on more solid ground than the author's aforementioned Noise/ISO/DR article.

Andrew, I'd be interested in hearing your take.
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