Why Exposing to the Right (ETTR) is BAD!

Started Mar 30, 2013 | Discussions
Barrie Davis
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(apaflo still ignored) nt
In reply to Barrie Davis, Apr 1, 2013
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Phil_L
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Re: that is not ETTL.
In reply to zodiacfml, Apr 1, 2013

Yes!

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schmegg
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Re: Why Exposing to the Right (ETTR) is BAD!
In reply to Barrie Davis, Apr 1, 2013

Barrie Davis wrote:

JulesJ wrote:

Barrie Davis wrote:

Jules,

1) If there is NO free space to the right of the histogram into which ETTR can take place, it is still perfectly possible to increase the signal to noise ratio. It is done by simply exposing at a lower ISO....

-(and, incidentally, doesn't need any messing about afterwards in post processing)-

2) Indeed, the process of ETTR is, itself, only ever "exposing at a lower ISO," even when there IS free space to the right into which the histogram silhouette can be shifted, since the ONLY way to shift that histogram is to use a longer shutter speed or wider aperture...(lower effective ISO)

3) Because of this, photography might as well ALWAYS be done at the lowest (practical) ISO, and this be used as a routine mechanism for reducing image noise....(the stated aim of ETTR)...

-(BTW, it IS what I do, as a matter of course and without having to think about it)-

4)... and nobody need bother themselves with this "Exposing to the Right" nonsense ever again!

I absolutely agree, in fact David Ward also taught us to shoot at native ISO (usually 100) whenever possible. But still doing that Shhoting to the Right might still be possible depending on the circumstances and use of f stop and shutter speed. It's not rocket science. It had just been obvious to me until it was brought to my attention. I don't do it religiously now, but I do keep it in mind.

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).

Probably because many people may not use their ISO setting to shift their histogram to the right.

Unless you actually use the ISO setting to shift the histogram, then there is no "ISO effect" on your image - so the concept, whilst being 'interesting', is largely irrelevant.

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?

Well - I think it's probably useful to consider ISO for what it is - and the only time when ISO settings will have an effect on the image when using ETTR is when you actually change it to achieve the histogram shift.

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JulesJ
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Re: Why Exposing to the Right (ETTR) is BAD!
In reply to apaflo, Apr 1, 2013

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???

Explain why you say that Apaflo. A criticism is no use without an explanation of exactly what you mean.

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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:

JulesJ wrote:

Barrie Davis wrote:

Jules,

1) If there is NO free space to the right of the histogram into which ETTR can take place, it is still perfectly possible to increase the signal to noise ratio. It is done by simply exposing at a lower ISO....

-(and, incidentally, doesn't need any messing about afterwards in post processing)-

2) Indeed, the process of ETTR is, itself, only ever "exposing at a lower ISO," even when there IS free space to the right into which the histogram silhouette can be shifted, since the ONLY way to shift that histogram is to use a longer shutter speed or wider aperture...(lower effective ISO)

3) Because of this, photography might as well ALWAYS be done at the lowest (practical) ISO, and this be used as a routine mechanism for reducing image noise....(the stated aim of ETTR)...

-(BTW, it IS what I do, as a matter of course and without having to think about it)-

4)... and nobody need bother themselves with this "Exposing to the Right" nonsense ever again!

I absolutely agree, in fact David Ward also taught us to shoot at native ISO (usually 100) whenever possible. But still doing that Shooting to the Right might still be possible depending on the circumstances and use of f stop and shutter speed. It's not rocket science. It had just been obvious to me until it was brought to my attention. I don't do it religiously now, but I do keep it in mind.

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).

Probably because many people may not use their ISO setting to shift their histogram to the right.

Assuming that the light level is not increased, only increasing exposure (shutter or aperture or both) can expose "to the right." Raising ISO would defeat the intention of lowering noise, since it does NOT increase the signal to noise ratio, but reduces it.

Unless you actually use the ISO setting to shift the histogram, then there is no "ISO effect" on your image - so the concept, whilst being 'interesting', is largely irrelevant.

The whole point is, it is NOT irrelevant. ETTR is, effectively, using a lower ISO. Are you one of those people I was talking about... ?? Or are you just tweaking my nose for some fun...

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?

Well - I think it's probably useful to consider ISO for what it is - and the only time when ISO settings will have an effect on the image when using ETTR is when you actually change it to achieve the histogram shift.

Oh dear. It isn't about the ISO value you happen to set the camera at. It is about the shutter speed and aperture settings you use to make the exposure. (sigh) It seems you ARE among the ranks of those that have yet to realise that.... when I thought you were kidding around.

Note: I am not prepared to explain in detail why a 400 ISO shot overexposed by one stop's worth of ETTR is actually exposed at 200 ISO. I have learned from bitter experience that anyone who cannot comprehend that simple fact for themselves, will not understand it any better when explained.

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JulesJ
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Re: ETTR and Blinkies.
In reply to Guy Parsons, Apr 1, 2013

Guy Parsons wrote:

JulesJ wrote:

The histogram gives much more valid information than the blinkies. I know your advice is given with good intent, but I think you should do some more in depth research into the use of the histogram.

That I fail to understand.

The histogram shows the exposure but has to be examined as to closeness of the data to the ends - the blinkies show that info much more readily. Way easier to spot the high/low limits.

Use blinkies for the actual photography, use the histogram in post to make things right.

Regards...... Guy

Ok. the blinkies have a use, they show clipping. But they do not show the real extent of the clipping just the areas, which are pretty obvious, the lightest parts of the picture. A glance at the Histogram gives so much more information about your expose at a glance. Over as well as under, how much, the distribution and how shooting to the right could improve the data in your image. Blinkies don't do all that. They are just a quick dirty way to see that you are clipping, no more.

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JulesJ
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Re: ETTR and Blinkies.
In reply to apaflo, Apr 1, 2013

apaflo wrote:

JulesJ wrote:

The histogram gives much more valid information than the blinkies. I know your advice is given with good intent, but I think you should do some more in depth research into the use of the histogram.

The histogram data and the highlight display data are identical,

no they are not, see my previous post.

and neither is more or less valid.

yes they are. See previous post.

It's just a different graphical display mechanism for the exact same data.

Mmmmm, see previous post.

Sometimes the histogram is more useful,

Ahhhhh!!!

sometimes the highlight display is more useful.

Nah1

The problem for most people is realizing exactly what each display is showing,

My point exactly.

and then being able to apply that information to decisions made about the next shot to be taken.

Quite.

Sometimes, when using the highlight display presentation, it can be quite useful to bracket three or four shots to see exactly how it changes, and then pick the exposure that does not blink in a particular area when the next higher exposure in the series did blink.

That is a complete waste of time given that you have the histogram to look art.

Or, conversly, choose the first of the series that did blink where the next lower exposure did not.

See above.

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JulesJ
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Re: Why Exposing to the Right (ETTR) is BAD!
In reply to Sovern, Apr 1, 2013

Sovern wrote:

Wow, lots of feedback in this thread. Glad to see that so many people are interested in talking about exposure and the subject of ETTR. I'm also glad to see that theres that agree with me that ETTR is not useful for everyone........

Not if you want more noisy images than your camera can actually achieve.

I will be posting a Youtube video tomorrow of my thoughts on ETTR and will be posting a link on here.

I look forward to that. It should fill up another thread!

All the best guys.

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JulesJ
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Re: Why Exposing to the Right (ETTR) is BAD!
In reply to Ysarex, Apr 1, 2013

Sovern. read Ysarexs's p[ost below carefuly. It is to you and makes a very valid point. To you.

Ysarex wrote:

Sovern wrote:

Wow, lots of feedback in this thread. Glad to see that so many people are interested in talking about exposure and the subject of ETTR. I'm also glad to see that theres that agree with me that ETTR is not useful for everyone........

I will be posting a Youtube video tomorrow of my thoughts on ETTR and will be posting a link on here.

All the best guys.

-- hide signature --

The photographer makes the gear, not the other way around.

The overwhelming majority of posts in this thread were added here to refute your original post. You have scant agreement at best.

And now after you've been repeatedly told you're in error you're changing your tune. Now a day later you say, "ETTR isn't useful for everyone....." That's a whole lot different than what you originally posted:

"I see a lot of new photographers learning about exposure and then quickly being told that they should use a method of exposure called Exposing to the Right (or rather, ETTL). I went into depth as to why in my opinion, ETTR is bad, and especially bad for new photographers that want to develop a consistent base for their ability to get correct exposure correctly the first time around with worrying about losing highlights.

Me personally, I believe in getting the exposure/shot correct the first time in the camera and exposing properly versus to the right as many benefits as shown in the article presented below."

ETTR may not be useful to you. That's perfectly fine. Chimping your exposure from the camera LCD is one way to approach the problem. ETTR is however very useful to those of us who know how to take advantage of it and make the very best photograph that current technology permits. Glad to see that you're acknowledging that now.

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mike703
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Re: Why Exposing to the Right (ETTR) is BAD!
In reply to apaflo, Apr 1, 2013

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.

In another discussion of this type recently about high-ISO shooting (link below), we were discussing pix taken at ISO6400 in which I had ETTR'd to help keep noise down as far as possible.  It was pointed out that it would actually be better to use a lower ISO (say, 800) but underexpose by three stops - effectively, exposing to the left - and then lifting exposure in PP.  This would give the same overall result in terms of IQ and noise - but would prevent highlight clipping.  It's exactly the converse of ETTR.

http://www.dpreview.com/forums/post/50841377

Best wishes

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schmegg
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Re: Why Exposing to the Right (ETTR) is BAD!
In reply to JulesJ, Apr 1, 2013

JulesJ 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???

Explain why you say that Apaflo. A criticism is no use without an explanation of exactly what you mean.

The reason I bought in was because this statement ...

"people seem incapable of associating exposing to the right with the consequent loss of film speed  (using an effectively lower ISO)."

That clearly does not make a whole lot of sense. And it took me a while to even work out why he made this statement.

I think what is being claimed is that an exposure adjustment must be made to expose the sensor for longer - and in this one way only it's analogous (perhaps) to shooting with a lower ISO. But in every other respect, unless the ISO setting is used to vary the exposure shift, then the ISO setting is irrelevant to ETTR. So the claim above is largely irrelevant and seems to just introduce unnecessary confusion to the topic IMHO.

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Barrie Davis
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What does he mean "Analogous" ?!
In reply to schmegg, Apr 1, 2013

schmegg wrote:

JulesJ 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???

Explain why you say that Apaflo. A criticism is no use without an explanation of exactly what you mean.

The reason I bought in was because this statement ...

"people seem incapable of associating exposing to the right with the consequent loss of film speed  (using an effectively lower ISO)."

That clearly does not make a whole lot of sense. And it took me a while to even work out why he made this statement.

I think what is being claimed is that an exposure adjustment must be made to expose the sensor for longer - and in this one way only it's analogous (perhaps) to shooting with a lower ISO. But in every other respect, unless the ISO setting is used to vary the exposure shift, then the ISO setting is irrelevant to ETTR. So the claim above is largely irrelevant and seems to just introduce unnecessary confusion to the topic IMHO.

See what I mean, Jules? From the above it becomes clear...

There are an awful lot of people that can't a get a grip on the idea that overexposing a 400-ISO shot by one stop's worth of ETTR is precisely the same (that is, employs same shutter speed and aperture) as exposing at 200-ISO...

..... and therefore IS using 200-ISO..

.....that is to say, there isn't the slightest photographic difference whatsoever.

I don't know whether to consider this state of affairs funny, or just rather sad... 

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Baz
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schmegg
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Re: Why Exposing to the Right (ETTR) is BAD!
In reply to Barrie Davis, Apr 1, 2013

Barrie Davis wrote:

schmegg wrote:

JulesJ 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???

Explain why you say that Apaflo. A criticism is no use without an explanation of exactly what you mean.

The reason I bought in was because this statement ...

"people seem incapable of associating exposing to the right with the consequent loss of film speed  (using an effectively lower ISO)."

That clearly does not make a whole lot of sense. And it took me a while to even work out why he made this statement.

I think what is being claimed is that an exposure adjustment must be made to expose the sensor for longer - and in this one way only it's analogous (perhaps) to shooting with a lower ISO. But in every other respect, unless the ISO setting is used to vary the exposure shift, then the ISO setting is irrelevant to ETTR. So the claim above is largely irrelevant and seems to just introduce unnecessary confusion to the topic IMHO.

See what I mean, Jules? From the above it becomes clear...

There are an awful lot of people that can't a get a grip on the idea that overexposing a 400-ISO shot by one stop's worth of ETTR is precisely the same (that is, employs same shutter speed and aperture) as exposing at 200-ISO...

..... and therefore IS using 200-ISO..

No - it's not using ISO200 at all - not if the camera is set on ISO400!

A sensor does not have a variable sensitivity - it's sensitivity is fixed. ISO is achieved by applying gain to the readout - and the higher the ISO setting, the higher the gain. That's it - nothing more.

So, if you expose at ISO400, then the gain applied is the same as if you ETTR at ISO400.

If you expose at ISO200, then the gain is different.

.....that is to say, there isn't the slightest photographic difference whatsoever.

I don't know whether to consider this state of affairs funny, or just rather sad... 

I'm not sure why you need to be so derogatory about this discussion.

As I said, perhaps I have misunderstood the gist of your point. But, based on what you've said above, then it would seem that your statements, at the very least, are a bit misleading.

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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:

JulesJ 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???

Explain why you say that Apaflo. A criticism is no use without an explanation of exactly what you mean.

The reason I bought in was because this statement ...

"people seem incapable of associating exposing to the right with the consequent loss of film speed  (using an effectively lower ISO)."

That clearly does not make a whole lot of sense. And it took me a while to even work out why he made this statement.

I think what is being claimed is that an exposure adjustment must be made to expose the sensor for longer - and in this one way only it's analogous (perhaps) to shooting with a lower ISO. But in every other respect, unless the ISO setting is used to vary the exposure shift, then the ISO setting is irrelevant to ETTR. So the claim above is largely irrelevant and seems to just introduce unnecessary confusion to the topic IMHO.

See what I mean, Jules? From the above it becomes clear...

There are an awful lot of people that can't a get a grip on the idea that overexposing a 400-ISO shot by one stop's worth of ETTR is precisely the same (that is, employs same shutter speed and aperture) as exposing at 200-ISO...

..... and therefore IS using 200-ISO..

No - it's not using ISO200 at all - not if the camera is set on ISO400!

That's where you are completely wrong.

However, I have already stated that I am not going to ping-pong postings on this matter. That is a pointless exercise. It is my opinion that if anyone does not understand this absolutely fundamental fact about the exposing of photographs, then it's likely they never will.

Moreover, if you, personally, ever get there, say, with somebody else's help, then GREAT...

.... but it isn't going to be my efforts that do it. Sorry. You must make your own arrangements.

A sensor does not have a variable sensitivity - it's sensitivity is fixed. ISO is achieved by applying gain to the readout - and the higher the ISO setting, the higher the gain. That's it - nothing more.

So, if you expose at ISO400, then the gain applied is the same as if you ETTR at ISO400.

If you expose at ISO200, then the gain is different.

.....that is to say, there isn't the slightest photographic difference whatsoever.

I don't know whether to consider this state of affairs funny, or just rather sad... 

I'm not sure why you need to be so derogatory about this discussion.

As I said, perhaps I have misunderstood the gist of your point. But, based on what you've said above, then it would seem that your statements, at the very least, are a bit misleading.

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Regards,
Baz
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Barrie Davis
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Re: Why Exposing to the Right (ETTR) is BAD!
In reply to mike703, Apr 1, 2013

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.

In another discussion of this type recently about high-ISO shooting (link below), we were discussing pix taken at ISO6400 in which I had ETTR'd to help keep noise down as far as possible.  It was pointed out that it would actually be better to use a lower ISO (say, 800) but underexpose by three stops - effectively, exposing to the left - and then lifting exposure in PP.  This would give the same overall result in terms of IQ and noise - but would prevent highlight clipping.  It's exactly the converse of ETTR.

http://www.dpreview.com/forums/post/50841377

Thank you, Mike.

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Regards,
Baz

also known as Barrie Davis, Associate of the British Institute of Professional Photography 
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schmegg
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Re: Why Exposing to the Right (ETTR) is BAD!
In reply to Barrie Davis, Apr 1, 2013

Barrie Davis wrote:

schmegg wrote:

Barrie Davis wrote:

schmegg wrote:

JulesJ 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???

Explain why you say that Apaflo. A criticism is no use without an explanation of exactly what you mean.

The reason I bought in was because this statement ...

"people seem incapable of associating exposing to the right with the consequent loss of film speed  (using an effectively lower ISO)."

That clearly does not make a whole lot of sense. And it took me a while to even work out why he made this statement.

I think what is being claimed is that an exposure adjustment must be made to expose the sensor for longer - and in this one way only it's analogous (perhaps) to shooting with a lower ISO. But in every other respect, unless the ISO setting is used to vary the exposure shift, then the ISO setting is irrelevant to ETTR. So the claim above is largely irrelevant and seems to just introduce unnecessary confusion to the topic IMHO.

See what I mean, Jules? From the above it becomes clear...

There are an awful lot of people that can't a get a grip on the idea that overexposing a 400-ISO shot by one stop's worth of ETTR is precisely the same (that is, employs same shutter speed and aperture) as exposing at 200-ISO...

..... and therefore IS using 200-ISO..

No - it's not using ISO200 at all - not if the camera is set on ISO400!

That's where you are completely wrong.

Really.

ISO is simply gain applied to the sensor readout.

If you shoot at ISO400 then you apply more gain to the readout than you do at ISO200. So, it's simply not the same at all.

However, I have already stated that I am not going to ping-pong postings on this matter. That is a pointless exercise. It is my opinion that if anyone does not understand this absolutely fundamental fact about the exposing of photographs, then it's likely they never will.

Believe me, I understand exposure very well.

The actual results you'll achieve will depend quite a bit on exactly what camera you are using. And I'd go so far as to say that your whole point here is pretty much completely irrelevant to the discussion of ETTR. Even one stop would often be more than what is required - meaning the actual difference in sensor saturation, readout noise, etc. would be negligible to the final image.

But, as I said, it does depend on what camera you might be using.

ETTR is simply exposing to the right. ISO should only enter the conversation if you intend to change it - otherwise it is irrelevant to the topic.

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schmegg
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Re: Why Exposing to the Right (ETTR) is BAD!
In reply to Barrie Davis, Apr 1, 2013

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.

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.

In another discussion of this type recently about high-ISO shooting (link below), we were discussing pix taken at ISO6400 in which I had ETTR'd to help keep noise down as far as possible.  It was pointed out that it would actually be better to use a lower ISO (say, 800) but underexpose by three stops - effectively, exposing to the left - and then lifting exposure in PP.  This would give the same overall result in terms of IQ and noise - but would prevent highlight clipping.  It's exactly the converse of ETTR.

And, as I've said, that depends a lot on what camera you use. You would definitely not be better off doing that with a Canon camera, for instance.

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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:

JulesJ 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???

Explain why you say that Apaflo. A criticism is no use without an explanation of exactly what you mean.

The reason I bought in was because this statement ...

"people seem incapable of associating exposing to the right with the consequent loss of film speed  (using an effectively lower ISO)."

That clearly does not make a whole lot of sense. And it took me a while to even work out why he made this statement.

I think what is being claimed is that an exposure adjustment must be made to expose the sensor for longer - and in this one way only it's analogous (perhaps) to shooting with a lower ISO. But in every other respect, unless the ISO setting is used to vary the exposure shift, then the ISO setting is irrelevant to ETTR. So the claim above is largely irrelevant and seems to just introduce unnecessary confusion to the topic IMHO.

See what I mean, Jules? From the above it becomes clear...

There are an awful lot of people that can't a get a grip on the idea that overexposing a 400-ISO shot by one stop's worth of ETTR is precisely the same (that is, employs same shutter speed and aperture) as exposing at 200-ISO...

..... and therefore IS using 200-ISO..

No - it's not using ISO200 at all - not if the camera is set on ISO400!

That's where you are completely wrong.

Really.

ISO is simply gain applied to the sensor readout.

If you shoot at ISO400 then you apply more gain to the readout than you do at ISO200. So, it's simply not the same at all.

However, I have already stated that I am not going to ping-pong postings on this matter. That is a pointless exercise. It is my opinion that if anyone does not understand this absolutely fundamental fact about the exposing of photographs, then it's likely they never will.

Believe me, I understand exposure very well.

The actual results you'll achieve will depend quite a bit on exactly what camera you are using. And I'd go so far as to say that your whole point here is pretty much completely irrelevant to the discussion of ETTR. Even one stop would often be more than what is required - meaning the actual difference in sensor saturation, readout noise, etc. would be negligible to the final image.

But, as I said, it does depend on what camera you might be using.

ETTR is simply exposing to the right. ISO should only enter the conversation if you intend to change it - otherwise it is irrelevant to the topic.

Sorry. If you want me to argue you will have to pay for another five minutes.

Argument clinic

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

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mike703
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Re: Why Exposing to the Right (ETTR) is BAD!
In reply to schmegg, Apr 1, 2013

schmegg wrote:

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.

That's how it came across to me.  And we all seem to agree that it makes sense.

In another discussion of this type recently about high-ISO shooting (link below), we were discussing pix taken at ISO6400 in which I had ETTR'd to help keep noise down as far as possible.  It was pointed out that it would actually be better to use a lower ISO (say, 800) but underexpose by three stops - effectively, exposing to the left - and then lifting exposure in PP.  This would give the same overall result in terms of IQ and noise - but would prevent highlight clipping.  It's exactly the converse of ETTR.

And, as I've said, that depends a lot on what camera you use. You would definitely not be better off doing that with a Canon camera, for instance.

Could you explain why?  As far as I can see if you underexpose by three stops (by using ISO 800 instead of 6400, but with the same exposure settings) you are just telling the camera not to multiply the signal by a factor of 8. Instead you do it yourself afterwards in PP (whilst protecting highlights).  Why would this not work so well with a Canon?

Thanks in advance

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schmegg
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Re: Why Exposing to the Right (ETTR) is BAD!
In reply to Barrie Davis, Apr 1, 2013

Barrie Davis wrote:

schmegg wrote:

Barrie Davis wrote:

schmegg wrote:

Barrie Davis wrote:

schmegg wrote:

JulesJ 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???

Explain why you say that Apaflo. A criticism is no use without an explanation of exactly what you mean.

The reason I bought in was because this statement ...

"people seem incapable of associating exposing to the right with the consequent loss of film speed  (using an effectively lower ISO)."

That clearly does not make a whole lot of sense. And it took me a while to even work out why he made this statement.

I think what is being claimed is that an exposure adjustment must be made to expose the sensor for longer - and in this one way only it's analogous (perhaps) to shooting with a lower ISO. But in every other respect, unless the ISO setting is used to vary the exposure shift, then the ISO setting is irrelevant to ETTR. So the claim above is largely irrelevant and seems to just introduce unnecessary confusion to the topic IMHO.

See what I mean, Jules? From the above it becomes clear...

There are an awful lot of people that can't a get a grip on the idea that overexposing a 400-ISO shot by one stop's worth of ETTR is precisely the same (that is, employs same shutter speed and aperture) as exposing at 200-ISO...

..... and therefore IS using 200-ISO..

No - it's not using ISO200 at all - not if the camera is set on ISO400!

That's where you are completely wrong.

Really.

ISO is simply gain applied to the sensor readout.

If you shoot at ISO400 then you apply more gain to the readout than you do at ISO200. So, it's simply not the same at all.

However, I have already stated that I am not going to ping-pong postings on this matter. That is a pointless exercise. It is my opinion that if anyone does not understand this absolutely fundamental fact about the exposing of photographs, then it's likely they never will.

Believe me, I understand exposure very well.

The actual results you'll achieve will depend quite a bit on exactly what camera you are using. And I'd go so far as to say that your whole point here is pretty much completely irrelevant to the discussion of ETTR. Even one stop would often be more than what is required - meaning the actual difference in sensor saturation, readout noise, etc. would be negligible to the final image.

But, as I said, it does depend on what camera you might be using.

ETTR is simply exposing to the right. ISO should only enter the conversation if you intend to change it - otherwise it is irrelevant to the topic.

Sorry. If you want me to argue you will have to pay for another five minutes.

Hehe

No, I don't really want to argue Baz.

And I think I know where you are coming from with your statement. But I find it to be possibly a bit confusing for beginners to grasp, without a decent explanation. So, IMHO (which you didn't ask for, I know), it would seem to be better to just have not brought it up in the first place in this discussion.

But I can imagine how much you probably care about what I think or indeed the beginners who are trying to learn stuff here.

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