Beginner Confusion over Exposure

[Forkbeard]

I was reading somewhere about 'exposing for the highlights' the other day which I've tried and understand the concept. But then I read about increased noise in shadow and 'exposing to the right'. Aren't these two completely opposing ideas or have I got it wrong somewhere? Surely if you're exposing for the more well lit areas, you're going to be under-exposing the rest of the shot? Or does ETTR just apply to the part of the composition you're aiming to 'get right'. I'm confused.

 

[gad-westy]

It's a little bit of a can of worms but the two aren't mutually exclusive. First thing I would say is that I would ignore both 'rules' if shooting JPEG. These are both techniques for extracting detail from raw files.

Exposing for the highlights essentially means don't clip the highlights. In other words don't let anything fall off the right hand side of the histogram.

Exposing to the right essentially means push everything on the raw file as far right on the histogram as possible to get maximum detail. It doesn't necessarily mean you should clip the highlights.

As ever, both of these philosophies are valid but aren't hard fast rules. There are many valid reasons to ignore either.

 

[woof woof]

Just to add...

I think that there are a couple of reasons to ETTR, to get detail in the shadow areas without having to boost the exposure and to capture a greater dynamic range. I forget the percentages involved but from what I do remember the higher percentage of dynamic range to potentially be captured is over at the right hand side.

I mention this because I've read on line articles more recently proposing that ETTR with some gear isn't as important as it used to be.

ETTR if at all possible is something that I personally find useful with my gear, Sony A7 and Panasonic MFT, backing off later in post capture processing.

 

[retrosi]

I have very recently read such an article & it suggested turning on the highlight priority custom function if available.
I have always turned mine off as I find it most annoying due to the flashing within the highlighted areas suggesting they are over exposed even in the smallest areas sky of sky when the whole image is clearly under exposed.
This to me shows if I had taken this line to ETTR I would either properly blow even more highlights or if ETTR means to push right as far as possible before blowing the highlights then nearly all my photos would be very dark indeed when the sky is involved.
I have found generally exposing for the highlights to a correct exposure causes most of the other areas to be near dark.
Therefore given this I do my best to balance as I always have even when using film as an average unless I want a certain look, either to the right or left.

Certainly ETTR helps bring the shadows out better, however, with LR or PS it is possible to both lower or raise certain sections to suit.
This for me has made myself ETTmiddle/Left more than the right.
As I prefer not to over expose the highlights & have often found them 'burnt' with 'CA'; & I know this is mostly caused by lenses not focused or not pulling the light into the exact point to give a true interpretation of the colour of the light waves entering the lens.
But I find even when correctly focused if ETTR'ed then the highlights are often too blown to recover backwards. And certainly my highlight priority is flashing away like mad.

So when I have exposed dead centre or 1/3 under I find that bringing up the shadow detail slightly doesn't cause the highlight to blow thus making for a well balanced photo.

 

[Nawty]

Whether you ETTR or ETTL depends on the sensor.

Typically, on older sensors you would ETTR as the shadows tend to be quite noisy but there was a lot of headroom in the highlights so dropping the exposure back in PP made sense to remove shadow noise.

Modern sensors have much much better noise control in shadows so you can ETTL to maintain highlights better.

To give an example, I've just spent a while going back through all my old raw files (D60, D90, D3200, D700, D610) to compare them to my new Olympus EM10. Basically, the EM10 looks to be a bit better in the noise department than the D90 when the pictures are exposed properly, however if I try and push any shadows or increase exposure then the D90 files quickly fall apart. The is not the case of the D3200, which holds up very well to pushing (as do both FF cameras).

So, my conclusion is that somewhere between the D90 and D3200 there was a shift in sensor technology which greatly reduced low level noise.

This shift in technology also applies to the the EM10 which has much more malleable files than the D90 and is more or less on a par with the D3200.

 

[retrosi]

Hadn't thought of the sensor technology making the difference. But I think what you say makes sense and goes a long way to explain why I ETTL mostly.

 

[gad-westy]

Whether you ETTR or ETTL depends on the sensor.

Typically, on older sensors you would ETTR as the shadows tend to be quite noisy but there was a lot of headroom in the highlights so dropping the exposure back in PP made sense to remove shadow noise.

Modern sensors have much much better noise control in shadows so you can ETTL to maintain highlights better.

To give an example, I've just spent a while going back through all my old raw files (D60, D90, D3200, D700, D610) to compare them to my new Olympus EM10. Basically, the EM10 looks to be a bit better in the noise department than the D90 when the pictures are exposed properly, however if I try and push any shadows or increase exposure then the D90 files quickly fall apart. The is not the case of the D3200, which holds up very well to pushing (as do both FF cameras).

So, my conclusion is that somewhere between the D90 and D3200 there was a shift in sensor technology which greatly reduced low level noise.

This shift in technology also applies to the the EM10 which has much more malleable files than the D90 and is more or less on a par with the D3200.

This makes for interesting reading. Not the first time I've read something along these lines and it certainly matches my perception in terms of using a D3 and D600 alongside each other. D600 shadows always appear far cleaner. Maybe resolution is helping here?

One question I therefore wonder is, if faced with a scene that is low in contrast, mainly mid tones with no extreme highlights or shadows to worry about, is it there any merit in ETTR when shooting raw or should one simply be looking to expose 'properly' from the outset?

 

[Nawty]

This makes for interesting reading. Not the first time I've read something along these lines and it certainly matches my perception in terms of using a D3 and D600 alongside each other. D600 shadows always appear far cleaner. Maybe resolution is helping here?

One question I therefore wonder is, if faced with a scene that is low in contrast, mainly mid tones with no extreme highlights or shadows to worry about, is it there any merit in ETTR when shooting raw or should one simply be looking to expose 'properly' from the outset?

The D700 (same sensor as the D3, as you know) was the first camera I owned where pushing the shadows yielded decent results and to be honest, at the time I was amazed with how good it was in this respect (it replaced the D90 and now having looked back I can see why I was amazed with the D700).

The D610 on the other hand takes it to another level, it is utterly insane, not only is it much less noisy in the shadows but it maintains colour balance much better and dynamic range at high ISO too meaning you can push the high ISO shots too (albeit with noise creeping in).

The D700 was definitely a ETTR camera as its highlight recovery was silly by the days standards.

The D610, unless the situation is extreme I just try and get it right in camera but would err on the side of highlight protection if the scene required it. My view tends to be that slightly noisy shadow (if I've had to push it really far) is better than blown highlights. I certainly wouldn't ETTR with the D610.

 

[gad-westy]

Thanks @Nawty. Great reply and I fully concur with your thoughts. Pretty amazing how far things have moved along.

 

[Nawty]

Back in 2012/13 when these 'new type' sensors first started appearing there was a load of internet fuss about ISOless cameras, in my view we're not there yet but the thought behind it goes to explaining what we are seeing:

http://1000wordpics.blogspot.co.uk/2013/01/what-does-it-mean-when-we-say-that.html

I believe Sony sensors are way way far in advance of Canon in this respect (although I don't really keep up to date with Canon things but I still hear people complaining of sensor banding when images are pushed a lot).

My new Olympus seems really good too, especially as the sensor is a few years old now - it was a game changer of a sensor for a lot of people, the first time M4/3 really competed with APSC).

 

[retrosi]

Some years ago I read an article regrading metering film, I used film and without realizing did then what I do now, ETTL. The article recommended ETTL and went on to show film processes proving to a massive degree the ability to pull detail from shadows and the highlight area became clean with clear decent detail. Just shows film had stacks of latitude to pull push as was often done.