I have been “doing” photography since the late 70s (well, since the early 60s if you want to count my early days with a Kodak Instamatic), and I sheepishly admit that I had to look up “ETTR”. Here is a pretty good explanation, if anyone else needs it:
It is the opposite of what I have been trying to do for the past ten years or so. I have apparently been trying to ETTL, because the auto exposure settings on my DSLR often result in blown highlights, combined with people explaining that it is easy to bring up underexposure, while it is impossible to truly recover from blown highlights.
If shooting RAW for later processing use ETTR, if working for Reuters use Jpegs and expose for the subject ignoring over exposed and under exposed areas (though with ten stops of dynamic range having detail in undesirable areas can be an issue).
Weddings are an interesting scenario where the photographer comes under a lot of pressure to show the pictures to the bride earlier, and yet what is on the rear of the camera as a Jpeg may be underexposed in a safety margin to retain the bride’s dress detail.
@Tim ETTR makes sense when we talk about digital photography, because we can generally assume that the photometric response of the sensor is linear until we hit cipping. In such situations, we want to maximise the signal-to-noise ratio by increasing the signal across a more-or-less constant noise floor. We can then adjust the gain digitally in post-production and apply a saturation curve as appropriate to the scene.
In the case of film, the characteristics of the film emulsion are fixed, and so it becomes much more important to set the exposure in-camera so that the key midtone aspects of the scene lie within the latitude of the film. In this case, we still want to ensure adequate exposure to avoid having to “push” the film too much during development, but ETTR itself doesn’t make as much sense.
Agreed that it doesn’t make sense in all situations, though I have found that reducing noise in the shadows (even if the scene doesn’t have that high of a dynamic range) can still be valuable since I often end up wanting to brighten them at least a little. Not having to try and calculate values for ETTR and “just shoot” the AEB is a nice feature to this approach.
That is a great feature. Does it let you take the successive images at different ISO values, or just different shutter speeds like AEB?
Thanks for the link - I agree that shooting at base ISO when doing ETTR makes sense (aside from noise, dynamic range is greatest at base ISO too). It seems hard to quantify how much new cameras can pull back the shadows with less noise, but from what I’ve read that definitely seems to be something that has improved in recent years.
Actually this one that I submitted recently is an example of this, and some of the variations that others posted did indeed look too dark to me on my screen.
Proper Exposure is very debatable with a simple thought exercise. Imagine a green grass lawn, this would be your mid-tone. If there is a shadow over the lawn but the exposure is locked on the sunlit part, then you are going to get a much darker green in the image but is that exposure correct?
It would depend, if you had a person standing in the shade then you are probably going to want to open up and not expose to the right because the quality of light in the shadow is going to be poor, bluish (as the lawn in shadow is lit from the blue of the sky and not the sun), so the proper exposure is going to put the mid-tone of the sunlit grass higher on a histogram and risk blowing it out because otherwise you are going to be raising the shadows where you would have a lot of noise.
It gets funky, when you have two people on the lawn, one in the shade one in the light, then the correct exposure is probably going to be the original (a reflector/ fill-in flash would then be useful).
Take a black cat on a pile of coal, the final image is going to have a histogram where almost every tone is going to be humped to the left, but relying on a camera reading without exposure compensation is going to give a RAW where the histogram is humped in the middle.
The fundamental thing is that the photographer takes control, he/ she makes an active decision what they want in the final image and then exposes for that effect.
Actually, I think it’s directly related to the improved usuability of high ISO values: in both cases, how far you can amplify the signal is dependent on the S/N in the shadows (the lights usually take care of themselves).
So if, with the same raw developer, an old camera gives good results at ISO 800, and a new one can go to 6400 with the same perceived quality, you’d have a gain of about 3EV in the shadows (very rough estimation).
However, do not just compare results for in-camera jpegs, or developments done with different (versions of) a raw developer: that technology also evolved… And that probably accounts for part of the perceived gain.
You could of course use one or more neutral gray cards to get a less subjective anchor in your image. In that way, there is a “proper” exposure for the selected gray card. But of course, as soon as you have different lighting situations within an image, there is no “one proper exposure” possible.
I don’t think that that method is very relevant for most amateur photography, although for professionals in certain areas it will be relevant (exact reproduction comes to mind).
A few weeks ago I opened this issue, requesting that a mode be added to the exposure module that allows you to select an area and specify where you want to place it on the brightness scale.
You seem to be bringing in artistic judgments, which aren’t necessary.
If the dynamic range of your scene is less than that of your sensor, then you can ETTR. The premise of ETTR is that you’re not going to any clipping.
If you dont have clipping, then you don’t need to assign the luminance value of “mid tone” to the sun-lit grass, you can decide this during post.
If the dynamic range.of your scene exceeds the dynamic ranger of your sensor, and you have no.means to control that contrast, like a fill flash, then ETTR is not as applicable and you must select which values you want to record. In this scenario, you will need artistic judgments, as this will determine what detial you can render in post.
Do you have a grey card or an incident light meter? as both would vary in readings depending on whether they are in the shadow or the light, grey cards also vary depending on how they are tilted, even colour temp is subjective.
My POV is that one should know one’s equipment and make a choice to expose for effect, or in Ansel Adam’s terms, expose to get the best negative possible to produce a print (digital or film), which is the same as shooting a portrait in shadow and exposing to blow the background out or shooting one in sunlit and blocking up the shadows behind the subject. It’s also the same as Mr Adam’s choosing to show as much detail in a landscape as possible. It’s all about the photographer choosing.
Not quite. If shooting in shadow but exposing for the highlights, in post one would be raising an image of person that would be blue and significantly more noisy than necessary. ETTR would give a poorer end result even though the RAW would have an even spread of tones across the histogram.
It only lets you vary exposure in stops, and while it’s not explicitly said, I believe it does that in the selected exposure mode (P,S,A). I wouldn’t see the utility of varying ISO, as it’s the amount of light on the sensor that primarily influences noise and that’s a function of exposure.
there are cases where an objective anchor in the image is needed;
having an area of known gray value can help in giving a basis for a defined exposure.
How to use that extra information is up to the photographer/editor.
And of course the reading on the gray card will vary depending on where in the scene it is. That’s why it’s used, to get a scene-defined value in the image. Again, how to use that is up to the photographer.
There are several factors in play here:
How do I expose the raw file to get optimal information: there you have to avoid clipping the important highlights, and where a middle gray zone ends up is not all that important.
How do I then edit that raw file to get an optimal rendition. There, a defined value in your scene gives you a known starting point.
Your exemple of a person in the shadow, in a scene exposed for the highlight is a bit of a red herring, as you are mixing two concepts: white balance and exposure. You can very well expose for the highlights with a whitebalance set to shadow. The more so as changing the camera white balance setting doesn’t change the raw file (it will change the embedded jpeg, but who cares?).
And if you expose for the highlights in such a scene, one assumes those highlights are important, so you need to keep detail there.
And Mr Adams didn’t have quite the same equipment as we have nowadays (which does not invalidate his words, but changes how to act on them).
Keep in mind, that when using accurate ETTR compared to a stronger under exposure, you get a larger exposure time, which in some situations can lead to more blur by motion of the camera or the subject
We do agree and in the context of this thread, proper exposure is subjective, which is my point, ETTR is not a fit all solution which your sentence
affirms by make a choice as to what is important. In the sunlit/ shadow scene mentioned as a thought exercise, the important highlights would change, the exposure for ETTR on the eyeballs of a person in shadow would blow the highlights of the sunlit areas and that’s fine. It’s probably not fine to ETTR (IMHO) on the whole scene and then pull the shadow areas up which would result in more noise and lower contrast on the person in the scene.
There is no correct exposure for the midtones, just like Mr Adam’s choosing to develop a neg for the most details in all areas by pulling (mainly) and getting a soft neg, it’s all a choice keeping final result in mind.
@Kofa could you simulate that now …there is a picker in the exposure module to let you use an area for exposure…maybe select that area see what ev you end up at and then add or subtract the amount of ev you need to get that to your desired set point …I am thinking off the top of my head and not sure that would be the number you desire but there is a picker in there so just thinking there might be a way to use it??
While I agree that proper exposure is subjective, Ansel Adam’s Zone System could be a way to make it objective. It can be done by measuring the luminance (L channel in either Lab or LCh) of different parts of the image (foliage, sky, skin, …) with the color picker tool to make sure it lies in its supposed “zone”.