selmslie Loc: Fernandina Beach, FL, USA

Here is an example of a scene where the DR was too high. To keep the highlights from getting blown I reduced the exposure by 1 stop and then recovered the highlights and shadows in Capture One. You can call it ETTR if you like. To me it's just highlight protection.

Same result except that my approach was much easier than ETTR.

(Download)

imagesintime Loc: small town, mid-America

I would invite each reader of this thread to download this example and save it to their computer. Then open it in the post processing software of choice and turn the highlight/shadow warnings on.

selmslie Loc: Fernandina Beach, FL, USA

That's probably not going to work since you need the raw file. I did not post that. There will be no blinkies for a JPEG. It is already limited to a range of 0-255 for each color.

Here is the next best thing. In this case I lowered the exposure slider to get rid of the highlight warnings in the editor. Then I brought back the shadows. This may not be the exact procedure I used on the JPEG I posted earlier. It may have had less exposure reduction and some highlight recovery instead but I did this just for practice.

The highlights I was looking at are in the path in the center of the image.

(Download)

amfoto1 Loc: San Jose, Calif. USA

Except when I have to use a high ISO.... which is quite often.

imagesintime Loc: small town, mid-America

No blinkies for a JPEG? If I open a JPEG in post I can set blinkies.

selmslie Loc: Fernandina Beach, FL, USA

With what editor? I only see blinkies on my camera or during a raw conversion.

selmslie Loc: Fernandina Beach, FL, USA

That brings us back to one of the fallacies in the ETTR pitch - that ETTR/EBTR can be used to reduce noise. It can't. It's additional exposure that reduces the visibility of noise by increasing the ratio of signal to noise.

For a demonstration that proves that visible noise is constant for a constant exposure see What is the Camera's Dynamic Range? and What is the Camera's Dynamic Range? - Part 2 in which the exposure is held constant and the ISO varied from 100 to 6400. With a constant exposure the visible noise did not change.

But ETTR or exposing for minimal blinkies does not always lead to an increase in exposure. There are times (wide DR scenes) when you need to use less exposure.

Low ISO encourages the use of greater exposure which leads you to less noise.

You need to be more careful not to blow the highlights when attempting ETTR.

If you still end up with more noise than you want your only recourse may be noise reduction in post processing.

imagesintime Loc: small town, mid-America

I don't work with JPEGs, but based on the comments on this site LOTS of people post process JPEGS. I would think most software allows setting highlight/shadow warnings. I happen to use Canon software.

altheman Loc: Christchurch, New Zealand

The benefit is a higher signal to noise ratio which produces the impression of less or a better looking noise in the image whether or not there is better colour who knows but I know with my camera -Sony a6000- (and sorry I do not have pics to prove it at this moment) that images produced at ISO's 800 and above certainly have less noise if exposed to the right.
One day I will produce some tests to prove the other stuff but will have to think about all the criteria required.

selmslie Loc: Fernandina Beach, FL, USA

Take a look at the two links I gave amfoto1 above. The exposure was based on ISO 800 and the histogram was moved up to three stops to the right and to the left by changing only the ISO. The visible noise did not change.

You get a little reduction in visible noise by increasing the exposure but if you increase the exposure by one stop and reduce the ISO from 800 to 400 at the same time you get the same noise reduction. ETTR has nothing to do with it.

Uuglypher Loc: South Dakota (East River)

Selmslie stated:
"That brings us back to one of the fallacies in the ETTR pitch - that ETTR/EBTR can be used to reduce noise. It can't" (Wrong! It demonstrably can !). "It's additional exposure that reduces the visibility of noise by increasing the ratio of signal to noise." ( read your words again Selmslie...and again and again if necessary to recognize that it perfectly explains the noise reducing effect of use of EBTR ... at ANY ISO!

The fact remains:

It is precisely the additional exposure due to using your camera's maximum DR through use of EBTR that allows the extra exposure and its resultant decrease of noise ( IRRESPECTIVE OF THE ISO USED) by permitting increased S:N.

See the illustration (below) of noise reduction via EBTR at even a ridiculously high ISO!


Selmslie stated:

. "There are times (wide DR scenes) when you need to use less exposure."
and
"You need to be more careful not to blow the highlights when attempting ETTR."

These statements are absolutely untrue and are equally absolute proof that he has not attempted to use his camera's full available dynamic range ... which, of course entails knowing his camera's full DR and using it to properly expose your raw captures:
"Expose for the brightest possible image, coming as close as possible to clipping highlight detail without actually doing so."

The facts remain that:

Such proper raw exposure involves filling the wells of brightest photo sites, but not to over flowing (save for specular reflections). When that is accomplished every other photo site, regardless of where in the histogram it appears, shall have received the maximum possible exposure proportionate to its position in that histogram. This is perfect exposure of a raw image data capture!
I must repeat...
"This is perfect exposure of a raw image data capture!"

Thus, in a properly exposed raw capture every photosite provides the maximum possible image data quality S:N (Signal-to-Noise ratio) from the brightest end of the histogram to the darkest.
You will have minimized whatever level of noise would have been expected (depending on your camera) relative to the ISO employed in the exposure. (Again, your nonsensical mantra that EBTR cannot be used to any benefit at higher than base ISO is patently untrue.)
The opportunity to render the greatest possible discernible shadow detail will have been maximized due to having captured the maximum possible tonal and chromatic spectra permitted by the image data's bit depth, and as a consequence, maximized the potential number of cusps of detail.
The resulting "brightest possible" image file is easily tonally normalized in the raw converter.

Thus, with accurate knowledge of your camera's maximum DR, and with reasonable care to properly practice EBTR there is no risk of clipped/blown highlights.

And last:
For many photographers the most important advantage of full DR use (assured by EBTR) is that the creative potential of that raw capture shall have been maximized such that it may be rendered in bright high-key, ominously noir low-key, and by an essentially limitless variety of range and tonal versions in-between - among which that image you pre-visualized is easily attainable. The creative potential of a properly exposed raw image capture dwarfs that of a raw capture limited by a JPEG's allotted dynamic range.

You really ought to give it a fair try, Selmslie...but, of course, that means you will actually ...finally...have to buckle down and accurately determine your camera's extra raw-accessible dynamic range.
If you would learn to properly expose raw image captures using your camera's full available DR , you would understand that EBTR is effective insurance against clipped highlight detail. But, again...you DO have to know your camera's extra raw-accessible dynamic range...which you have admitted that YOU DO NOT KNOW!

Try this for starters:

ETTR is to purposefully expose a 12 or 14 bit-depth raw capture as if it were an 8 bit JPEG file exposed to just barely avoid highlight detail clipping. In so doing you will be reducing your image's tonal and chromatic spectra by 50%, stepwise, for each full stop of available DR that you neglect to use.

EBTR is to expose a raw capture to produce the brightest possible image that comes as close to clipping highlights without actually doing so. ..which requires utilizing your camera's maximum available DR.

Signing out,
Dave

(Download)

gplawhorn Loc: Norfolk, Nebraska

Well, as the OP I've learned several things. First, I need to really learn what my camera can and can't do. Second, RawDigger can be a useful tool for understanding what my camera is actually giving me. Third, people get pretty passionate about their favorite approaches. And fourth, Selmslie needs to stop beating around the bush and just come out and say what he thinks.

selmslie Loc: Fernandina Beach, FL, USA

Thanks for proving my point so clearly. In your example, it is not ETTR that reduced the noise. It was the additional exposure when you went from 1/320 sec to 1/125.

But why stop at a mere 1-1/3 stop of additional exposure. You could have gone further with the noise reduction by adding even more exposure. How about 1/15 sec? Oh, wait. you could not do that because you used such a ridiculously high ISO. The raw file would have passed beyond its upper limit at 1/100 (1-2/3 stops).

You would have ended up with the same amount of visible noise if you had set the ISO to 6400 or 800 exposing at 1/125. It would just have need more gain applied during the raw conversion to normalize it. I already proved that in What is the Camera's Dynamic Range? and What is the Camera's Dynamic Range? - Part 2. Visible noise is a function of exposure, S/N, not ISO.

I could easily get much less noise than you did just by dropping the ISO from 6400 to 800 and the exposure from 1/125 to 1/15. This would eliminate nearly all of the noise. And I could keep going all the way to base ISO.

I will shortly post another exhibit to show what happens to the raw file (using RawDigger) in a case like the one I posted here. Remember that one? It's where the exposure was held constant and the ISO varied from 100 to 6400. It proved that a constant exposure results in the same visible noise after normalization.

As you keep your head in the sand on this topic you will never realize that what I am saying makes sense. Or maybe you just don't understand how it works.

Rongnongno Loc: FL

Good luck with that. This guy loves to read himself.

selmslie Loc: Fernandina Beach, FL, USA

The new thread is at What is the Camera's Dynamic Range? - Part 3