Correct use of exposure compensation

[thegman]

Hi everybody, I've just completed an online course '' The fundemantals of photography'' In this the tutor said he prefers to step down a stop as all the information is there and can be recovered in PP. I have also just read about ''exposing to the right'' now I'm confused? What do the forum members recommend?

[Shadowman]

Either or.

Sometimes you can expose too far to the right, where exposing to the left is a bit safer and this comment definitely depends on the scene being photographed. My preference for choosing expose to the right/left typically has to do with the amount of time available to setup the shot (still life images come to mind) and the amount of work I want to spend on editing the final output. This weekend I did a couple of informal portraits around 7PM that required very little editing and the shots were just quick grabs. Earlier in the day I was fighting with mid afternoon sunlight so I was trying to tame the sunlight, exposing to the right was out of the question.

[Inkanyezi]

We just had a rather lengthy discussion on the subject, under the thread Histogram: Luminosity and color

One conclusion is that it is not quite clear to all of us exactly what is meant by the phrase "expose to the right", but in most presentations of the paradigm, it does not in any way suggest clipping the highlights, only exposing so much that the bulk of the histogram is at the right side, but ending somewhat before or exactly at the right end.

So "exposing too far to the right" is not ETTR. However the discussion did conclude, from the scribblings of the writer of the first article on the subject, that it indeed does mean, that exposing to the right should be done also when the sensor can register a larger dynamic range than that of the subject, and consequently making the image darker in PP.

This is something that I would hardly ever practise, but I do use compensation, pushing the histogram to the right, when I want to use a faster shutter time than exposing to the right at base ISO would permit. Hence, if the dynamic range of the scene is less than the sensor's ability to capture, ISO can be raised and exposure kept to the right, but ISO adjusted so that the exposure falls within the sensor's dynamic capability.

Evidently, my practise defeats the purpose of exposing to the right, as first presented. By exposing less, I not only move highlights and shadows to the right, but also noise, which is more evident in the darker parts of the exposure. However, whenever higher ISO is desirable, it makes sense to keep exposure to the right, to avoid excessive noise in lowlights and to utilise as much as possible of the dynamic range of the medium.

To me is seems a rather academic solution to the "problem" of noise and lack of tonality in shadows, to always expose to the right, even when the dynamic range of the scene is far less than that of the sensor. Imagine for example a rather normal dynamic range of about 8 stops, and a sensor with 14 stops capturing capability. Exposing to the right, at base ISO, would push all data into the upper eight stops of what the sensor can capture, leaving in its wake six full stops that are not used, and "over-exposing" the scene by about three stops, later to be recovered in PP by pulling brightness down.

The situation outlined did not exist when the first article about exposing to the right was written. Sensors had a range of at best about ten stops, but many couldn't capture more than about eight. It was more important then to keep exposure sufficiently far to the right. We have more leeway now with more modern sensors. We can keep a safety margin to the right almost always, preventing colour shifts and single colours clipping. Only when we raise ISO to a certain level, the ETTR paradigm becomes important in order to get good image quality, when the dynamic range of the sensor is the same as that of the subject or less. In the latter case, deciding what to sacrifice, highlights, shadows, or both.

[pnodrog]

Hi everybody, I've just completed an online course '' The fundemantals of photography'' In this the tutor said he prefers to step down a stop as all the information is there and can be recovered in PP. I have also just read about ''exposing to the right'' now I'm confused? What do the forum members recommend?

The scene, metering method and dynamic ranges of the scene and the sensor are the main factors for setting the exposure compensation which in some cases may end up being a full 4 stops one way or other. I always think of exposure preference such as + ETTR(shadow noise reduction) or - highlight protection insurance as artistic or style choices by the photographer as a preferred exposure bias usually at most + or - 1 stop that is added to the underlying required exposure compensation.

[dje]

In this the tutor said he prefers to step down a stop as all the information is there and can be recovered in PP.

Hi Gerry

I think your tutor is probably "playing it safe" to avoid blowing highlights. It's easy to do with overcast skies or when there is a fair bit of white cloud in the sky. I often use negative EC of 1/3 or 2/3 to avoid highlight clipping. I'd rather have a little more noise in the shadows than clipped highlights. Shooting raw is safer too because blown highlights can be recovered to some extent in pp.

Dave

[Manfred M]

Everyone is entitled to his or her own opinion on photography, and that includes metering.

My starting position tends to be what my camera meter tells me other than when I recognize that are likely to result in an improper exposure (for instance snow (or white sand beach) scenes which have a tendency to come out too dark or night shots that tend to come out too light). In these circumstances I will take some test shots and dial in exposure compensation, if that is required. I have found that with modern cameras, that scenes that would not have come out properly seem to do so. I may do something else (including ETTR) if I don't like the look of the histogram. That being said, I'm just as likely to switch to manual in those circumstances.

I'll do something similar when shooting flash at times as well. I tend to "drag the shutter" to bring in ambient light into a scene and I'm still looking for balanced looking lighting. Again, I may use flash compensation, but often find that switching to manual exposure (on both camera and flash) gets me what I want, rather than trying to fight what the camera thinks the scene should be exposed at...

[Mike Buckley]

Considering that the tutorial was about the fundamentals, implying that you don't have a lot of experience, I think it should have taught you to make several exposures of the same scene when time is allowed (unlike when shooting birds in flight). You can then use the exposure that most meets your needs.

[DanK]

My rule of thumb is that most rules of thumb are simplistic. It makes no sense to try to come up with a general rule that would apply regardless of both the characteristics of the scene and the effectiveness of the metering. With respect to the latter, metering isn't always spot on, and if the metering in a given image happens to tend toward underexposure, the last thing you would want to do is underexpose more.

The more sensible approach, IMHO, requires more judgment. Decide how you want the image exposed, check the histogram, and if it is overexposed relative to what you think is desirable for that scene--e.g., if you are blowing highlights, or the midtones are too high--then dial in negative exposure compensation. If the situation is the reverse, dial in positive exposure compensation. Or adjust manually.

[AB26]

Hi Gerry,

It has rightfully been said that there are no general rules in photography, what works for the one does not work for others and depending on camera make and model the “rules” will differ.

I followed this “argument” about exposing to the right or not. In my experience it is better to expose to the right when the main subject in the scene is predominantly white, like a bride’s dress. When I say expose to the right it does not mean clipping the histogram to the right. Shooting a white subject to the left will leave you with whites looking grey. With white highlights in the right hand fifth of the histogram, white will be white provided you get the white balance right.

Using the histogram on your camera to get exposure “right” will give you a good indication when to use exposure compensation. Trying to keep the graph in the histogram between the “walls” on the left and right will give you “ideal” exposure. Ideal exposure might not look right on the LCD screen of your camera but without clipping either to the left or right of the histogram you will be recording more data to work with in PP, without having to “manipulate” the image to get it looking like what you want it to look like.

Best way of doing it is to experiment with what works best for you. All of us have a way of finding a recipe that works best for our own way of doing it.

One lesson I have learned in Photography is not to believe everything others say, take note of what is said and test it for yourself, finding a way that works best for you.