“Expose to the Right” & relation to ISO Invariance

[digitaldog]

And assuming the ISO 100 was correctly exposed, now the (cropped out) highlights are totally clipped.

Not the case with my or presumably Guillermo's images.

By underexposing the ISO 100 shot 16x (so we create 4 stops headroom for the subsequent amplification), we then and only then can improve the S/N ratio on some cameras without clipping highlights, like the Canons, by increasing the ISO setting 16x.

Again not the case with my or presumably Guillermo's images. My ISO 100 image is correctly exposed as recommended by the incident meter.

However, bracketing exposures creates much better image quality for such stationary subjects, and just a bit more work in postprocessing.

I doubt anyone would or could disagree with that technique.

[Bart_van_der_Wolf]

Not the case with my or presumably Guillermo's images.  Again not the case with my or presumably Guillermo's images. My ISO 100 image is correctly exposed as recommended by the incident meter.

Then either the image was underexposed (you can check with RawDigger how far it was from clipping), depending on how your exposure meter was used, or the output clipping was masked by Lightroom's (default) highlight restoration.

Cheers,
Bart

[digitaldog]

Then either the image was underexposed (you can check with RawDigger how far it was from clipping), depending on how your exposure meter was used, or the output clipping was masked by Lightroom's (default) highlight restoration.

I agree, it's not ETTR and thus 'under exposed' for optimal data. The meter wasn't telling me about ideal exposure for raw, that's part of my point.
In terms of the 'disconnect' between LR and true clipping, just how much are we talking about, 1 stop, 1/2 stop, 1/4 stop?

[Guillermo Luijk]

Achieving ETTR through ISO only makes sense when exposure doesn't suffice to make it. In the real world this happens hundreds of times (low light conditions, large DOF requirement, quick action,...).

Regards

[digitaldog]

Achieving ETTR through ISO only makes sense when exposure doesn't suffice to make it. In the real world this happens hundreds of times (low light conditions, large DOF requirement, quick action,...).

Indeed it does!

[Bart_van_der_Wolf]

In terms of the 'disconnect' between LR and true clipping, just how much are we talking about, 1 stop, 1/2 stop, 1/4 stop?

Depends on the Raw and the camera it was taken with, but theoretically can be up to 5 stops. One would need to take a finely bracketed series to find out, and compare Rawdigger's real Raw data, with the point where LR would start showing the clipping indicator. Possibly also for each ISO that one wants to know it for.

Shooting a newspaper should give some (paper) structure in highlights, and some dark greys that will become mid grey. A better target would be a stepwedge with 0.10 density increments like a Stouffer 2110, because plotting the RGB values will show how the roll-off is near the clipping point, and the steps will show as spikes on the histogram, narrow spikes for low noise, wider spikes/humps for high noise, if surface reflection are avoided.

Cheers,
Bart

[digitaldog]

Depends on the Raw and the camera it was taken with, but theoretically can be up to 5 stops.

5 stops! I don't think my Canon would come close to that, in fact I know it can't. LR can recover, rebuild, whatever you want to call it, 5 stops (darn, 1 stop) from true raw clipping?
I'd have guessed, in my case, nor more than 1/2 stop. Perhaps less.

[Bart_van_der_Wolf]

5 stops! I don't think my Canon would come close to that, in fact I know it can't. LR can recover, rebuild, whatever you want to call it, 5 stops (darn, 1 stop) from true raw clipping?
I'd have guessed, in my case, nor more than 1/2 stop. Perhaps less.

Using RawDigger (or Fast Raw Viewer) will take the guesswork out of it ...

Cheers,
Bart

[digitaldog]

Using RawDigger (or Fast Raw Viewer) will take the guesswork out of it ...

I will but what camera system did you test with the above that was 5 stops over? I want one.

[Bart_van_der_Wolf]

I will but what camera system did you test with the above that was 5 stops over? I want one.

Lightroom (process 2012) will allow a 5 stop ''Exposure" correction. When the clipping indicators will show up depends on the subject colors, white balance, and level of under exposure, which we don't know at this moment. The choice of profile may also play a role.

Cheers,
Bart

[digitaldog]

Lightroom (process 2012) will allow a 5 stop ''Exposure" correction. When the clipping indicators will show up depends on the subject colors, white balance, and level of under exposure, which we don't know at this moment. The choice of profile may also play a role.

Using Rawdigger, I'm seeing about 1/2 stop between the two products. I was able to expose 1.5 stops over the meter before clipping specular white (BableColor tile) in LR using PV2010, RD showed clipping. With the 1 stop over meter, RD shows no clipping. The 2 stop over meter is blown out in with PV2010 however with 2012 it isn't. But close (-2.30 on exposure slider).
What's rather interesting is the 1.5 over, that really is over according to RD looks great with the LR recover and has less noise than the 1.0 over. Go figure. I've also thought exposure and development are hand in hand. Yes, at 1.5 over meter, RD says I'm clipped. But the image? Looks better.

[digitaldog]

Lightroom (process 2012) will allow a 5 stop ''Exposure" correction.

But have you found a capture or raw that can utilize this much correction, that's the question.

[AlterEgo]

Lightroom (process 2012) will allow a 5 stop ''Exposure" correction.

you can always add extra stops through .dcp profile - BaseineExposureOffset tag

[digitaldog]

you can always add extra stops through .dcp profile - BaseineExposureOffset tag

Begging the question, how far can you go ETTR+PV and get good results?

[Bart_van_der_Wolf]

But have you found a capture or raw that can utilize this much correction, that's the question.

I tend to expose to the right, so I have no (severe over-exposure) examples of regular shots that need such levels of correction at hand unless I start digging in my HDR shots. But then, we're rather talking about deliberate underexposure in this thread, and I will have an even harder time looking for those, especially in a 8x or 16x scenario. The lowest exposure in an HDR sequence is typically the ETTR exposure, the rest in longer to collect more photons in the shadows. When in doubt for regular shots, I bracket exposures and only keep the ETTR exposure (choice determined by RawDigger's closeness of the highlights to the clipping level).

Cheers,
Bart

[digitaldog]

I tend to expose to the right, so I have no (severe over-exposure) examples of regular shots that need such levels of correction at hand unless I start digging in my HDR shots.

Ditto. For real casual shooting, I have exposure compensation plus 3/4 to 1 stop. If I have the time, I'll tweak or bracket.

But getting back to something maybe new, can we, should we ETTR+D meaning exposure + development. I'm from the old analog B&W and color film darkroom days. I spent my share of time trying all kinds of exotic developers for TechPan. I wouldn’t think of considering exposure and ISO without knowing about developing the neg. I'm wondering why that shouldn't be true today and if so, just the differences between the raw converters and their controls should be part of the picture. Going full circle, if a Canon shooter and in one of the common situations Guillermo mentioned, also adjust ISO.

[AlterEgo]

Begging the question, how far can you go ETTR+PV and get good results?

I don't know - I am just pointing to a technical possibility to overcome UI limitations in ACR...

[digitaldog]

I don't know - I am just pointing to a technical possibility to overcome UI limitations in ACR...

One man's limitations could be another man's Technidol! 

[jrsforums]

I agree, it's not ETTR and thus 'under exposed' for optimal data. The meter wasn't telling me about ideal exposure for raw, that's part of my point.
In terms of the 'disconnect' between LR and true clipping, just how much are we talking about, 1 stop, 1/2 stop, 1/4 stop?

http://mulita.com/blog/?p=3358  George Jardin on LR headroom

[Jack Hogan]

Begging the question, how far can you go ETTR+PV and get good results?

Sensors are pretty well linear devices, so you can go as low as you can stand in terms of SNR if your converter is well behaved without penalty (it turns out that LR is not but others are).  If a sensor has a 14 stop acceptable SNR (the engineering definition) then by recovering 5 stops you've essentially got 9 (14-5) to display.  Most papers are doing great when they show 7 stops of DR so you've got some latitude to play with in PP.  Heck most cameras from just a few years ago were lucky to capture 9 stops of DR...

Jack