[stevebrot]

It is my understanding based on observation that some raw converters recover more highlight detail than is actually in the recorded image

That is sort of hard to do. One cannot manufacture detail out of thin air or even bits; what you capture is what you have. What is not obvious is that half the tones are defined for that last step of bit-depth, meaning that there is a incredible amount of potential detail in those last few highlight EV steps. LR tends to keep those tones in reserve for use in highlight recovery when the highlights are not truly clipped. That is not a bad thing, mostly because our eyes are not so good at discerning bright detail. LR intelligently remaps those tones down into regions where they are more useful.


Steve

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Last edited by stevebrot; 12-29-2020 at 03:22 PM. Reason: clarity

[GUB]

LR intelligently remaps those tones down into regions where they are more useful.

In other words - guesses.

[stevebrot]

In other words - guesses.

Guess a little here...dither a little there...


Steve

[GUB]

Guess a little here...dither a little there...


Steve

And does a good job admittedly.
But I would rather commit extra noise from say a stop of underexposure than utilise it.

[TonyW]

A couple of points about some of the applications mentioned here.

Rawdigger does not mess with highlight reconstruction or manipulate image data in any way that is not its purpose - it is not an editor It presents raw data as it is in the file I.e. the numerical data values. The data in the histogram is true to the captured raw data.

Lightroom similarly needs to present an ‘acceptable’ rendering of raw data. Over the years Adobe has changed and refined the process versions.

IF, you are trying to judge exposure and clipping by the histogram shown in LR you are being misled. What may look close to overexposed or even clipped is due to Adobe applying Baseline Exp Comp. etc to achieve the rendering for screen. Consequently you may find that in real terms your SOOC raw image data is actually underexposed by 1.5 stops. You may find that many other raw editors take a similar route

EDIT: Ian covered some of this in post #10

[stevebrot]

Rawdigger does not mess with highlight reconstruction or manipulate image data in any way that is not its purpose - it is not an editor It presents raw data as it is in the file I.e. the numerical data values. The data in the histogram is true to the captured raw data.

Yes, it is a true histogram (frequency distribution) of the capture data. If one prefers, the same is available in tabular form. It is that functionality that convinced me to pony up the bucks for a copy some time ago.


Steve

[Cerebum]

To quote John Cleese ...... “My brain hurts”

This is superb information that I will carry with me as I get to be a better photographer. I have to admit I don’t tend to go for the technical aspect in this level of detail until I have a base understanding, which I now have. I feel as though I have crossed another threshold and am moving forwards again. Thanks guys. You never cease to impress

BEST FORUM EVER!

[Rondec]

When I am shooting landscapes I expose to the left (blown highlights are the bane of my existence), when I am shooting portraits I expose more to the right.

[stevebrot]

When I am shooting landscapes I expose to the left (blown highlights are the bane of my existence), when I am shooting portraits I expose more to the right.

...and here is an example of different usage of terms. I am pretty sure that most of the participants on this thread use ETTR to avoid blown highlights. There is confusion on the Web as well with some sources meaning one thing and some another.


Steve

[Rondec]

...and here is an example of different usage of terms. I am pretty sure that most of the participants on this thread use ETTR to avoid blown highlights. There is confusion on the Web as well with some sources meaning one thing and some another.


Steve

Is exposing to the left not deliberately underexposing, while exposing to the right is pushing the exposure up to the edge of blowing highlights? Because I just find that if I underexpose a little extra I don't lose anything if shooting low iso on a tripod, but if I push the exposure up, I can't get the highlights back.

[stevebrot]

Is exposing to the left not deliberately underexposing, while exposing to the right is pushing the exposure up to the edge of blowing highlights?

Good question. Exposing to the left with some users means placing exposure to the shadows with exposing to the right meaning placing exposure to the highlights. Other users use your definition of intentional underexposing vs. pushing the bleeding edge of clipping for highlights. There is a hard limit both directions, data-wise, with the harder and more abrupt limit being on the low end.*


Steve

* I know that last is against invariate ISO doctrine, but numbers don't lie. Both zero and 214 are undefined for image processing purposes.

[jatrax]

while exposing to the right is pushing the exposure up to the edge of blowing highlights?

That is correct as I understand it. And what I do. The important point is "up to the edge". If you have blown highlights you have blown highlights. Certainly underexposing is the safer choice in that regard. However, ETTR will in my experience give you more detail to work with and less noise. But if you go too far you blow the highlights irrecoverably. That is one of the reasons I use the histogram on the camera. Since it is from the jpg I am confident that if all I get is a few blinkies in pure white areas then using the RAW I am still safe. I have no idea how that would work on other cameras but it has been a good rule of thumb for me with the K-3II and K-1II.

[TonyW]

Worth considering also that ETTR really only applies at your cameras base ISO and also would be implemented when the scene dynamic range does not exceed the dynamic range of your camera.

[stevebrot]

However, ETTR will in my experience give you more detail to work with and less noise.

That is my understanding as well and has been my practice when shooting transparency film since pretty much forever. The shadows come along for the ride and everyone is happy, at least within the limits of dynamic range (traditional sense of the term).


Steve

[stevebrot]

FWIW...

For challenging subjects having both important shadow and very bright highlights (i.e. no middle ground for exposure), the answer is to do a bracket series with intent to merge in PP.


Steve