Luminous Landscape Forum

Equipment & Techniques => Digital Cameras & Shooting Techniques => Topic started by: brucehughw on October 14, 2019, 06:29:32 pm

Title: The Right Histogram
Post by: brucehughw 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 hasnít 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
Title: Re: The Right Histogram
Post by: josh.reichmann 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. Itís a great and useful piece.
Apologies for the psych out. Itíll hopefully be back up in the following days!

Best,

Josh
Title: Re: The Right Histogram
Post by: digitaldog 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 Photoshopís Levelís command.
Histograms donít 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 (http://www.youtube.com/watch?v=EjPsP4HhHhE)
High rez: http://digitaldog.net/files/Histogram_Video.mov (http://digitaldog.net/files/Histogram_Video.mov)
Title: Re: The Right Histogram
Post by: bwana 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.
Title: Re: The Right Histogram
Post by: digitaldog 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.
Title: Re: The Right Histogram
Post by: DP 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 ?
Title: Re: The Right Histogram
Post by: digitaldog 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.
Title: Re: The Right Histogram
Post by: Doug Peterson 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.
Title: Re: The Right Histogram
Post by: Ray Cox 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
Title: Re: The Right Histogram
Post by: DP 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
Title: Re: The Right Histogram
Post by: kimballistic 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
Title: Re: The Right Histogram
Post by: digitaldog 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. Thatís 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/
Title: Re: The Right Histogram
Post by: kimballistic 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.
Title: Re: The Right Histogram
Post by: kimballistic 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.
Title: Re: The Right Histogram
Post by: smthopr on February 20, 2020, 07:26:31 pm
This just got me thinking...

In motion picture work, we often use a waveform monitor to graph exposure.  It has the advantage of showing exposure by it's position in the frame which can be quite useful.

It would be nice, I would think for still camera companies to consider the waveform vs. the histogram...
Title: Re: The Right Histogram
Post by: BAB on February 22, 2020, 04:10:51 pm
A raw histogram by channel would be the BOMB! everything else is just an educated guess.
Title: Re: The Right Histogram
Post by: chez on February 22, 2020, 08:27:29 pm
A raw histogram by channel would be the BOMB! everything else is just an educated guess.

But once you get to know your camera...that educated guess is pretty damn good, at least from my perspective.
Title: Re: The Right Histogram
Post by: DP on February 23, 2020, 05:36:21 am
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.

indeed, also for example +Brian Caldwell or -Rodney  ;D
Title: Re: The Right Histogram
Post by: DP on February 23, 2020, 05:37:52 am
This just got me thinking...

In motion picture work, we often use a waveform monitor to graph exposure.  It has the advantage of showing exposure by it's position in the frame which can be quite useful.

It would be nice, I would think for still camera companies to consider the waveform vs. the histogram...

true raw based blinkies/zebra can suffice better