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Thread: 120 FPS Global Shutter!!! and more

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    Super Moderator Kayaker72's Avatar
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    Just noticed the native ISO range of ISO 250 - 25,600. I have seen references to 120 fps officially lasting 1.6 seconds (my count was pretty good!), a bit more noise than usual at higher ISOs, but not awful noise.

    I am not trying to be too critical of the A9 III, but just trying to get past the headlines. From my perspective, the programable FPS is probably the feature I am most interested in but is also the feature I can see getting me into the most trouble. Respect....but no thank you. I like the idea of no flash max sync speed. But, whenever I am using flash, 1/125 - 1/200th is my target shutter speed anyways, 'cause, you know, I need a flash because there isn't much light. Max shutter speed of >1/8000, again, sounds amazing...except even on bright days I usually max out at 1/4000th. I do occasionally see wobbles with electronic shutter, but a faster readout speed will likely solve that.

    Actually, the most impressive thing I may have heard about the A9 III is how people are raving about the AF system. I always need/want a better AF system.

    But, then the negatives, CFE Type A cards...no. RAM of 8 GB...that is likely the same as my current R5, so actually not that impressive. Native ISO of 250 to 25,600. I could say what I care about is how clean the ISO is, but I am often using ISO 100 even ISO 50 on bright days. And there are reports (granted preliminary) of some slightly increased noise. So, no thank you.

    I often fall back by thinking of % of pictures a new feature would allow me to get. I have no doubt I will buy a new camera someday; I enjoy gear too much. But I fully admit my R5 has a very small % of images that I try to capture where it can be improved upon. Next gen AF system, 14 bit for all files, not changing fps with battery life, control over fps in electronic shutter, better control over video button, a legit pre-capture mode, a few things like that. And, if they can get better IQ...somehow...always better IQ. But the R5 is a beast of a camera. I am very happy with it.

  2. #2
    Senior Member neuroanatomist's Avatar
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    Quote Originally Posted by Kayaker72 View Post
    Just noticed the native ISO range of ISO 250 - 25,600.
    Global shutter comes at a price – noise. According to DPR, Sony claims the a9 III, "...doesn't compromise on ISO performance or dynamic range." Giving them the benefit of the doubt, I suppose they mean that at base ISO the sensor is no noisier than, for example, the a9 II...at the same ISO value. However, going from ISO 100 to ISO 250 on the a9 II costs a stop of DR, and the DR of the a9 II at ISO 100 is already a stop lower than the R3 at ISO 100. Oh, how the times have changed...

  3. #3
    Super Moderator Kayaker72's Avatar
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    Quote Originally Posted by neuroanatomist View Post
    Global shutter comes at a price – noise. According to DPR, Sony claims the a9 III, "...doesn't compromise on ISO performance or dynamic range." Giving them the benefit of the doubt, I suppose they mean that at base ISO the sensor is no noisier than, for example, the a9 II...at the same ISO value. However, going from ISO 100 to ISO 250 on the a9 II costs a stop of DR, and the DR of the a9 II at ISO 100 is already a stop lower than the R3 at ISO 100. Oh, how the times have changed...
    Yep. And you have to start asking why is the base ISO 1.3 stops higher than the R3?

    I did a quick search, while specifically regarding the A9 III, I didn't find that, but Global Shutters in general, it seems that the "solution" allowing a Global Shutter isn't that the data is all processed instantly (if you think about it, 24 million readings/calculations/adjustments truly instantly does not seem likely). The "solution" is to have on-chip and even in-pixel memory. So the data from 24 MP is instantly moved to memory which is they read sequentially by the processor. If that memory is located adjacent to the pixel well, it is taking up surface area on the sensor, so you actually are using less than the full sensor surface area (apparently this has been the case with several sensors), smaller pixel wells (which might lead to a smaller ISO range?). The other option seems to be having the memory behind the pixel well, so the sensor surface area is unimpeded, but you have more distance between a heat sink at the back of the sensor and the pixel wells. Either way, by having on chip memory, you are adding a step to the process and each step increases noise.

    Or so I read/watched.

    In a way I am glad Sony did this: 1) push the envelope; but 2) mentally, I am now only really looking for faster read speeds.

  4. #4
    Senior Member neuroanatomist's Avatar
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    Quote Originally Posted by Kayaker72 View Post
    In a way I am glad Sony did this: 1) push the envelope; but 2) mentally, I am now only really looking for faster read speeds.
    I'm sure we'll see a global shutter from Canon at some point. Canon is definitely not an envelope-pusher when it comes to sensors. Personally, I have not had any issues with rolling shutter effects on the R3. The readout speed is nearly as fast as a mechanical shutter. If Canon brings a stacked sensor to the 5-series, that would give you what you want (or...buy an R3 ).

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