Dual Gain Sensors for Digital Cameras

[@marklaurendet1861]

It is interesting how good some of the older cameras are compared to the newer ones.

[@muru0210]

As always, great education! Thank you Scott 👍

[@ronaldbuitendijkfotografie]

Very informative, thank you! Apparently for my camera iso 640 is the turning point.

[@WildlifeInspired]

Glad it was helpful!

[@mirkoputignano7734]

Very helpful, thank you

[@CharlieGroh]

I saw this Photons to Photos study when I bought my Z9...since, I've just set it at ISO 500 and left it, unless requiring more "help." Actually started this tangent with my D4 and later D5. Noise in all of these cameras doesn't present many problems for me as I shoot high school sports/pageantry events and lighting is usually pretty bad, so I have to adjust to the conditions in post via the usual suspects in software. I think these flagship cameras produce some elegant noise...lol.

[@WildlifeInspired]

I have also played with at times.

[@guykerr8111]

I enjoyed the explanation and found it helpful. Another aspect to mconsider. Thanks.

[@WildlifeInspired]

Glad it was helpful!

[@isoawe1888]

Thanks. I’ll keep it at ISO 500 until I’m underexposed more than 1 1/2 stops, then I’ll start bumping it. Bringing back a stop in post doesn’t seem to degrade image at all.

[@WildlifeInspired]

Truth.

[@brucewilliamsstudio4932]

Brilliant! I would never have known this without your detailed analysis.

[@davidwinther621]

I enjoy your videos . Does the Z8 have this feature? David

[@WildlifeInspired]

Yes. Same sensor as the z9

[@Joseph-iu6ip]

Great explanation and samples.

[@bengundy3372]

Thanks for an informative video, explained what a dual gain sensor is all about. Waiting for your Z6III video.

[@WildlifeInspired]

Its coming!! Recorded and set up soon.

[@TerryKontopoulos]

Great Scott! Next the Invariance" 😄

[@yoyo.251]

Thanks for the video, it is very informative. I have a question, from the charts it looks like the Z9 sensor has worse read noise and dynamic range performance than D800 upto iso 400. And at higher ISOs they are similar. So isn't the D800 sensor better than Z9 accross all iso values? And in that case, what is the merit to using a dual gain sensor?

[@yoyo.251]

Upon closer inspection, it looks like on the Z9, the read noise performance is slightly better than D800 at higher ISOs. Though the dynamic range is almost the same at higher ISOs.

[@terrygoyan]

Check out the curve on the Nikon D3S camera. It has at least four different in camera gain settings. It jogs all over the place!

[@danbrown8979]

Nice explanation! I notice that the color noise is greater/different between the low gain and the high gain. Don't know the significants of that? I am thinking that using auto iso plus manual with the Z9, I will try to be aware of the iso and skip up to 500 or higher from 400 if possible. I don't know if I will be that aware while shooting birds? It would be nice to be able to disable iso 400!

[@WildlifeInspired]

That's my usual setting. Though sometimes I sill dial in ISO 500 and shoot aperture priorities. Not often.

[@Mthompson4545]

Hi Scott. I just continue to learn more and more valuable information from you. This did make sense to me and I look forward to your next photo basics video. - Mick Thompson

[@WildlifeInspired]

You are amazing. If you ever have questions let me know n

[@Mthompson4545]

@ Do you happen to know if the OM-1 Mark II has a dual gain sensor and what the sweet spot is if it does?

[@Weldon2004]

The Photons to Photos website plots have always intrigued me, especially the Read Noise in DNs versus ISO Setting :-). Seeing the effects of a dual gain sensor and its "sweet spot", as you mentioned, has me often thinking about locking in that crossover point where ISO 500 looks as good as ISO 100. I haven't yet taken the time to shoot and actually compare the image differences at those two ISO values but I still often find myself choosng the sweet spot anyway :-). I am a bit concerned with comparing different camera models as sown in the graph. The Photons website notes at the bottom of the graph that "These raw values are not appropriate for comparing camera models because they are not adjusted for gain or area." I'd like to hear more about that caution to understand just what I can safely infer when comparing two cameras. For example, the Canon R5 vs R5mII vs R5mII in ES mode all show ISO 500 as the sweet spot but with increasing noise between them. What is it fair to say about those graph differences? 🙂

[@WildlifeInspired]

I have this criticism abiut using the graphs and its more about showing the trend graphs. Like one is worse but then gets better. When using two different sensors, I try to make the point to see the comparative trends and not the absolute values. I'll try to be more careful. I am done with this series and not sure how much more I'll be referencing this.

[@richardpontius8210]

Great informative video.

[@WildlifeInspired]

Thanks for watching!

[@BobN54]

This is a tricky topic, and unless you get the basics right you'll get it wrong. You asked us to let you know if you got it wrong, so here goes. I'd advise abandoning the 'exposure triangle' altogether, it just carries too many misconceptions. You keep saying 'light to the sensor' - which is what exposure actually means - it wouldn't be necessary to say that if the triangle hadn't obfuscated the meaning of 'exposure'. 'Brightening it' is part of that misunderstanding You say 'turning up the luminance' but you really aren't. The luminance is part of the exposure, the bit that isn't time (that is, the 'amount of light' is the luminance - aka 'brightness' or 'intensity' - times the time for which it is allowed on the sensor). Suggesting that ISO changes the luminance is just promulgating the whole misunderstanding, the one that goes with saying that 'ISO' is gain, which it isn't. Conversion gain also isn't really a gain at all - it's confusing terminology employed by engineers. This isn't really anything about 6th grade versus professor, it's just that when you start with the wrong basic concepts - which is unfortunately very common these days - it's very hard to make sense of it. So let's start with the basic concepts: Luminance - intensity of light shining from, on or through something Exposure - the luminance on the sensor times the time for which it's allowed to shine (by the shutter). This luminance on the sensor is controlled by the scene luminance (brightness of the light coming from the scene) and the f-number (not the 'aperture'). Lightness, sometimes called 'value' or 'density' - how light or dark something looks to human vision. It's really important to understand that this is different from 'luminance'. Think of a print. It has a lightness going from black (0%) to white (100%). The luminance (how much light is coming from it) depends on the illumination of the print. Likewise for a display, it displays from black to white, how much light (luminance) that is depends on the display, how much it's brightness is turned up. The output of the photographic process (in terms of how light or dark something looks) is lightness - that's what the numbers in the output file tell you, not 'brightness' or 'luminance'. ISO - a number that specifies how the exposure (at the input) relates to the lightness (at the output). Specifically the ISO defines the exposure required to produce a lightness of 18%. The higher the ISO, the smaller the exposure for 18% lightness (the formula is 10/exposure, measured in lux-seconds, - lux being the unit of luminance and seconds the unit of time) Notice that no 'gain' is required to raise the ISO. All that will happen is that different lightness numbers are produced for a given exposure. Variable voltage gain is used in most cameras, to allow the camera to measure small exposures more accurately, but that's not saying that ISO is gain (which is fundamentally wrong), simply that variable gain is used to help cameras work at high ISOs. Note that if you don't distinguish between exposure and lightness it becomes impossible to understand what ISO is. anyhow, unfortunately the state of photographic education today is such that many photographers are using these terms, which denote quite different concepts, interchangeably, and thus getting very confused. If someone thinks that 'exposure' means the amount of light on the sensor and also how light or dark the photo looks, then 'gain' becomes the only plausible explanation (in this usage it effectively means 'magic'). If they think that the output from a camera is 'luminance' and so is exposure, then 'gain' would be necessary, wouldn't it? But it isn't, so it isn't necessary to add 'luminance'. Unfortunately, you've succumbed to some of these confusions in this video (like talking about 'turning up the exposure in PS, which is impossible of course). Unless you're very careful to separate these terms you'll get yourself into knots. OK, what is a dual gain sensor? Well, in sensor design there is a relationship between the light capacity of a pixel and the amount of electronic noise (read noise) that you see. This noise manifests mainly as shadow noise, and is very visible if the highlights aren't very much brighter than the shadows, as in low light shooting (i.e. at high ISOs). The higher the pixel capacity the greater the noise. The relationship is determined by a sensor parameter called 'conversion gain' - unfortunately, because it isn't 'gain' at all - it's simple the relationship between the photo charge in the pixel and the voltage that the pixel outputs. It's controlled by the internal capacitance of the pixel. A dual-gain pixel can change the capacitance, so it can have a low conversion gain for low ISOs and bright light, when the shadows are a big luminance range away from most of the picture and a high conversion gain for high ISOs and dim light, when the shadows won't be far from the highlights and a large pixel capacity isn't needed. Sorry for the long post. Not trying to be negative. It's just that these topics are so mangled these days on the Internet, it's very easy to be led astray and unwittingly contribute to the mangling.

[@WildlifeInspired]

I will strive to use specific terms more accurately in my videos. Generally, my goal is to convey a conceptual message-in this case, about why camera sensors behave differently at various ISO settings. However, I want to be more precise with terminology and be cautious with terms that are often used interchangeably, such as brightness, lightness, and luminance. I often confuse lightness and luminance, even though I understand that they are not the same. My photography has always emphasized fieldwork first, as I believe that’s where exceptional images are created. But as I address these topics for my audience, I want to be as accurate as possible without being overly technical. I think you understand the purpose of the video, and I certainly recognize the importance of using precise terminology. Let me know if you volunteer your technical assessments of my videos and screen them for accuracy before posting. Pay is $0 but you get the reward of knowing you helped.

[@juliogonzalez6918]

Duh, still not understanding

[@WildlifeInspired]

Can't help ya man.