Thank you very much, that is a very useful lesson, you used practical examples to highlight key concepts. One of the best videos I watched in the "exposure settings"
Until 7:00, it was all spot-on in the explanations. But not anymore, then. ISO setting does NOT "adjust the sensor's sensitivity to light", absolutely not. As you mentioned, this is a "gain" setting (as written in some broadcast and cinema cameras), meaning it is an amplification of the signal. The sensor's sensitivity is fixed by design, and this is the business of the manufacturer to do so. They will choose to conceive either a highly sensitive sensor (such as in the Sony A7S3, or in specialized scientific cameras) or a poorly sensitive sensor (such as many cinema cameras, that request lots of artificial or natural light to function). But this level of sensitivity is FIXED, and it will never change nor anyone will ever be able to change it. What ISO (or "gain") does is amplifying the signal received by the sensor, thanks to the whole electronic circuitry attached to it. It works a similar way to what sound amplifiers (or preamplifiers, if you go into details) do. They receive a signal with a fixed level and their circuitry amplifies it when you turn the knob (or press the dedicated button). A sensor's sensitivity will never change, from the moment it leaves the factory to the moment it shall cease to function, and that is crucial to understand. Because when we understand this concept with ease, we also understand why there may be distortion applied to the signal if we want to amplify it too much. In digital imagery, this distortion is called "noise" or, more precisely, "digital image noise" : the purple/grey/green/etc colours we see in the images created with a high ISO level ( = a high level of amplification, and a high level of distortion as a side-effect). Telling users they can change the sensitivity of their cameras sensors will lead them to believe they can adjust this indefinitely without any negative consequences, and this is very misleading. If one uses a film camera, the sensitive surface can change every time a new film is inserted into the camera body. The user will decide to use the same film or not, giving him the freedom to change the sensitivity of the surface as a result. In digital imagery, this freedom is lost (then we get many others in return) and we have use sensors with fixed (or determined by design) sensitivity, also named "native". Hope this was a clear and simple enough explanation, so everyone has a decent understanding of how things go in the digital ages. If not, I can always try to improve those explanations.
It is very true that iso is not technically the camera sensors sensitivity to light. But I think it's a sufficient enough explanation for beginners. I don't think they will assume they can adjust this setting indefinitely, as you say, seeing as it is also discussed in the video that noise is a byproduct of manipulating this setting. Thanks for taking the time to watch and comment.
Thank you very much, that is a very useful lesson, you used practical examples to highlight key concepts. One of the best videos I watched in the "exposure settings"
You're very welcome!
Love these guides thankyou from england!
Thanks so much for the kind words!
Thank you good info
My pleasure; thanks for taking the time to watch and comment!
Until 7:00, it was all spot-on in the explanations. But not anymore, then.
ISO setting does NOT "adjust the sensor's sensitivity to light", absolutely not.
As you mentioned, this is a "gain" setting (as written in some broadcast and cinema cameras), meaning it is an amplification of the signal.
The sensor's sensitivity is fixed by design, and this is the business of the manufacturer to do so. They will choose to conceive either a highly sensitive sensor (such as in the Sony A7S3, or in specialized scientific cameras) or a poorly sensitive sensor (such as many cinema cameras, that request lots of artificial or natural light to function). But this level of sensitivity is FIXED, and it will never change nor anyone will ever be able to change it.
What ISO (or "gain") does is amplifying the signal received by the sensor, thanks to the whole electronic circuitry attached to it.
It works a similar way to what sound amplifiers (or preamplifiers, if you go into details) do. They receive a signal with a fixed level and their circuitry amplifies it when you turn the knob (or press the dedicated button).
A sensor's sensitivity will never change, from the moment it leaves the factory to the moment it shall cease to function, and that is crucial to understand.
Because when we understand this concept with ease, we also understand why there may be distortion applied to the signal if we want to amplify it too much. In digital imagery, this distortion is called "noise" or, more precisely, "digital image noise" : the purple/grey/green/etc colours we see in the images created with a high ISO level ( = a high level of amplification, and a high level of distortion as a side-effect).
Telling users they can change the sensitivity of their cameras sensors will lead them to believe they can adjust this indefinitely without any negative consequences, and this is very misleading.
If one uses a film camera, the sensitive surface can change every time a new film is inserted into the camera body. The user will decide to use the same film or not, giving him the freedom to change the sensitivity of the surface as a result.
In digital imagery, this freedom is lost (then we get many others in return) and we have use sensors with fixed (or determined by design) sensitivity, also named "native".
Hope this was a clear and simple enough explanation, so everyone has a decent understanding of how things go in the digital ages. If not, I can always try to improve those explanations.
It is very true that iso is not technically the camera sensors sensitivity to light. But I think it's a sufficient enough explanation for beginners. I don't think they will assume they can adjust this setting indefinitely, as you say, seeing as it is also discussed in the video that noise is a byproduct of manipulating this setting. Thanks for taking the time to watch and comment.