Semantics: the meaning of a word, phrase, sentence, or text.
If we don't care about the meanings of the words we use, I fear our discussions will not be fruitful.
April 7, 2023
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you can't say this ... iso value dialed by you ( or selected by firmware ) can be a lot of different things - starting from altering a well capacity before exposure starts to camera models where all iso is implemented as iso-by-tag ( and no capacity changes, analog amplification or digital multiplication happens at all )
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in some camera models WB settings affects metering too ... so w/ UniWB for example your camera firmware itself might meter for more exposure of the same scene, etc
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Firmware may deserve a special mention, though it runs on electronics ;)
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Of course not. In manual mode, the ISO, SS and aperture are fixed. EC cannot do anything for either raw or jpeg captures. In fact for my camera in manual mode the EC cursor vanishes and there is no way to even make an EC adjustment. When not disengaged in manual, then EC will affect both raws and jpegs.
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Yes, but mostly the 'gain' argument doesn't ever bother with the firmware. As you know, I think the use of the term 'gain' in this context, to beginners, is distinctly unhelpful.
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In your opinion, is amplification better?
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I avoid using this word, it is unnecessary and confuses the matter, it's like trying to explain everything with gear ratio.
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But does amplification cover conversion factor and multiplication?
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I think it's worth paying for.
Don -
It certainly could do that.
- The act, or result of amplifying, enlarging, extending or adding.
- (physics) The act, or result of independently increasing some quantity, especially voltage, power or current.
- (electronics) Gain.
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I think the A and S modes are more often used than the M mode. The M mode is most suited to slow work, with a tripod and plenty of time.
Don Cox -
I use M mode a lot when at or above the ISO setting where the conversion gain is changed to the high setting. It allows me to maximize the exposure and not worry about clipping.
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Not better at all. In both cases, one needs to specify just what it is being 'gained' or 'multiplied'. It's not the charge measured in the pixel. It's not the exposure. What it is, is an arbitrary value somewhere in the middle of the image processing value, which might be expressed as a voltage or a digital number. What the processing chain is essentially doing is mapping from exposure, expressed as a charge to lightness. I don't see why we'd bother about what are the intermediate values when explaining to a beginner, or anyone, unless you actually know. 'gain' in terms of photons/DN (which isn't a 'gain' in my book) is of interest when doing sensor analysis, but none at all in normal photographic practice.
My experience when you use either term to beginners, the idea that they come across with is that it is light that is being gained or amplified, because nothing else makes any sense the way the whole thing is explained. -
So in all cases, what is it that is being enlarged, extended, added or increased?
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Hi Jim.
Damn glad to see you on this site. I always enjoyed your words of wisdom and equanimity on the DPReview forums.
Best,
Joe
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Some cameras do allow exposure compensation in Manual mode. Once you realize Exposure Compensation is simply a meter bias, it makes sense. In manual mode, most cameras give feedback as to whether or not the camera thinks the exposure is appropriate for the ISO setting. There is nothing wrong with biasing that feedback.
Some cameras allow exposure compensation when in manual mode with Auto-ISO. In that case biasing the meter affects the selected ISO, which will affect the lightness of the camera produced JPEG.
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Exposure Compensation simply biases the camera's metering system. Often the camera's metering system will affect (perhaps indirectly) the exposure and ISO.
We could have quite a discussion of metering systems, and how they affect shooting, but I think that's best for a different thread. In terms of the direct effect of Exposure Compensation, all it does is bias the meter. Everything else is a result of the meter's biased reading.
