Why Exposing to the Right (ETTR) is BAD!

Started Mar 30, 2013 | Discussions thread
Barrie Davis
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Re: Why Exposing to the Right (ETTR) is BAD!
In reply to schmegg, Apr 1, 2013

schmegg wrote:

Barrie Davis wrote:

schmegg wrote:

Barrie Davis wrote:

schmegg wrote:

Barrie Davis wrote:

mike703 wrote:

apaflo wrote:

Barrie Davis wrote:

What puzzles me (actually, I am completely mystified) is why people seem incapable of associating exposing to the right with the consequent loss of film speed  (using an effectively lower ISO). I have had long ping-pong type exchanges in these forums with posters who just could NOT accept that THAT was what was happened. Quoting the actual shutter speeds and apertures USED at them just didn't help, because they didn't associate THOSE with any particular ISOs, either, it seems.

Why is that, do you think?

Because what you just said doesn't make any sense at all???

Sure it does; it's completely clear.  If you have a scene which averages mid-grey and has a histogram in the middle of the range when correctly exposed, and then you ETTR, you are using a longer exposure to get more light hitting the sensor (as much as you can without clipping highlights) and reduce noise.  Which has exactly the same effect as reducing the ISO.

Quite so.

Sure. That's not exactly what Baz said though.

Yes it is! Mike's was different form of words, to expand the point, but with same meaning.

Furthermore, if you cannot SEE that it is the same meaning, it becomes obvious why there is so much difficulty in your understanding the point itself.

Oh really.

You see to be very sure that your a bit better than me don't you.

The fact remains, if you have the camera set on ISO400, a different gain will be applied to the sensor readout than it will at ISO200. Meaning it's not "exactly the same" at all.

Or do you deny this?

Or maybe it is - but he's too keen to fob me off and say I have no idea rather than try to explain himself better.

I already explained that I have found people who don't understand this extremely basic principle for themselves, tend not to understand even when it IS explained. For this reason I now stop trying at the first sign of dispute.

You say it's "extremely basic" and yet you've been unable to explain it on this occasion, or, by the sounds of it, on many past occasions.

So perhaps it's not a "basic" as you think. Or perhaps you are wrong.

Of course, this doesn't help ME to understand WHY it is that people have so much trouble understanding ... [???]

Perhaps it's because you don't explain yourself! LOL!

And I can't understand why increasing exposure being the same as lowering ISO, which is as blindingly obvious to me as being poked in the eye with a sharp stick, ...

- ("blindingly" ... get it?)-

... should so COMPLETELY pass by the sensibilities of ANYone who claims knowledge of photography, that they actually dispute it even when poked in the eye with that SAME sharp stick.

Amazing!

But, like I say... maybe we will both have to STAY mystified.... [??]

Last night I watched "The Girl Who Played With Fire" in the original Swedish.. It was very good, if a bit violent and gory. In that a guy famously gets tasered in the gonads, and yet doesn't even flinch.

He didn't notice the blindingly (achingly?) obvious, either.

I have no beef with you Baz - nor do I want to start something. I hope that much is clear.

I do find, however, your avoidance of answering my questions and your assertions that I know nothing to be a little ignorant, or at least arrogant. And I'd have hoped I'd have received a little better treatment from someone who has been on these forums for as long as you seem to have been.

I've looked at your gallery and there is some nice and well executed product-style photography there - so I assume that you know a bit about how to take a photo.

As I've asked before, if you shoot at ISO400 but expose for ISO200, then the gain applied to the sensor is different from that which would be applied had the shot been taken at ISO200. And that, in my book, means it's NOT "exactly the same".

In both cases the amount of light striking the sensor is identical... that is, an amount that is correctly exposed for 200-ISO. The fact that for one of the shots the camera happens to be set, not at 200, but to 400-ISO with 1 stop of overexposure for ETTR, alters NOTHING.

They are both 200-ISO exposures.

In other words, they are photographically the same, both exposed at 200-ISO, by means of shutter speed and aperture settings commensurate with that 200-ISO rating.

It is, after all,  shutter speed and aperture settings USED which determine which ISO was USED.

As you have stated yourself, the ISO on the dial means nothing, because what happens AFTER the 200-ISO's worth of light has been recorded by the sensor is neither here nor there. The ISO setting of the camera is indeed irrelevant to the strength of the exposure which has already been made...

... all it does is "position" the features of the histogram after the event with more or less amplification in firmware...

...or in SOFTWARE, if you are messing about with the tonal structure afterwards in a computer the way proponents of ETTR would have us do.

Now, does THAT make it any clearer for you?

I ask, because for most people it doesn't, at least not usually. Most people just argue, and I'm not in the mood for that, I'm afraid.

-- hide signature --

Regards,
Baz
=
"Ahh... But the thing is, these guys were no ORDINARY time travellers!"

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