Reader Comment: ETTR Technique Results in Too-Bright Images for Review
Related: baseline exposure, digital sensor, Dominik W, Expose Somewhat To Right, Expose To The Right, exposure, histogram, LibRaw, Nikon, Nikon mirrorless, Nikon Z8, RawDigger, reader comment, Sony, Sony A7R, Sony A7R II, Sony A7R III, Sony A7R IV, Sony A7R V, Sony mirrorless, technique
re: Case Study: Sony A7R V: Metering, Dynamic Range, ETTR/ESTR, Camera Histograms, ETTR
re: Nikon Z8: Color Shift when Using Optimal ETTR
UPDATE: see Sony A7R V: Perfect ETTR at ISO 50/100 using Zebra Display
too dark and 2 stops dynamic range wasted
Dominik W writes:
I have been following your coverage of the ETTR and ACR baseline exposure issue with great interest. I have come back with some files from my last winter outing that were 2 stops underexposed by the camera.
[DIGLLOYD: snow guarantees a ~2 stop underexposure, the camera wants to make a middle gray tone from bright white snow!]I have a few questions regarding the process.
I have followed the article here https://www.rawdigger.com/howtouse/deriving-hidden-ble-compensation in terms of zeroing out the values of the image.
1) Is there a way to apply this setting in a way where the -1.35 exposure (and other settings) are the new 0 on the sliders? This would be especially useful for the curve which is baked with a bunch of points after the process version conversion.
2) When shooting with nearly 2 stops of over exposure through an EVF, a lot of stuff is blown out, making compositional judgements in certain scenes difficult. Same for reviewing the JPG images on the camera before returning home from the field. Do you have any suggestions in terms of improving this workflow?
DIGLLOYD: first, I think the baseline exposure thing is not worth exploring much because it won’t really help you on a practical anything. If you are willing to do the linear workflow and all that, it’s still a huge problem actually shooting the stuff.
For a partial solution to these issues, see:
ETTR, Camera Histograms vs RAW Histograms, ISO 100 vs ISO "Lo"
Root cause
The core issue is the foolishness of all camera vendors of conflating and coupling capture exposure with output image brightness. There is not one camera on the market today embraces raw capture and what it implies—everything is a raging JPEG dumpster fire of configuration complexity, poor metering vs sensor capabilities, etc. Even JPEG-only shooters get screwed because the exposure is sub-optimal for JPEGs also.
In the digital realm, this is a fundamentally flawed algorithmicallly-broken dumpster fire, because it discards much of the sensor capability. A failure t≠o rethink this broken model underlies the firmware of all of today’s cameras.
Dealing with the brightness issue
= problematic image brightness in camera!
The optimal ETTR exposure is often +1 or even +2 stops more than the camera thinks is right. That leads to washed-out previews when reviewing things on the camera, as seen at right. Ditto for any JPEGs the camera produces.
There is no good way to deal with this, there are only partial mitigations. After all, the JPEG you are reviewing (even shooting RAW it’s the embedded JPEG) has all the settings baked-in.
The only approach that can help there is choosing settings that reduce the effect.
There are several tips that help at the end of the Sony A7R V analysis, one particiular tip a major help.
One suggestion I have for ETTR exposures is that half a loaf is better than none. Meaning that +1 stop vs +0 stops is a big win, even if +2 stops would be better. Either:
- Expose somewhat more eg ESTR and/or
- Bracket, evaluate the darker exposure(s) to assess what you need to assess but also shoot the lighter ones. This dovetails with simultaneously providing a margin of safety for not rblowing-out all the captures.
Of course #2 is not viable under lots of circumstances including handheld or focus stacking; you have to get it right since bracketing is not possible. In that case, think in terms of ESTR and be happy with half a loaf.
Abe H writes:
This is no solace for stills shooters, but on many Sony video cameras including some mirrorless photo cameras, they have a Cine EI exposure system where you record the image at native ISO but rate the sensor and preview the image at a different ISO, say, 2 stops lower. I don't personally use this system as a matter of preference, but it mitigates some of the issues you're discussing.
DIGLLOYD: that sounds like it’s along the right lines.
