11.08.2023

Global Shutter arrives. World radically changed within hours. Early adopters already ensconced in the Photography Hall of Fame. All previous cameras rendered useless.

 Here we go. The GSO. The global shutter onslaught. Breathless bloggers and video influencers have also changed history by declaring that Sony has invented a whole new way of capturing images that no one else in the world had the foresight or technology to create. 

Well.... maybe not so fast. I think a small company that designs and produces imaging sensors solved the technical stuff of G.S. well over a decade ago. For that matter Arriflex, Red, and Panasonic have been using global shutters in high end video cameras for.....a long time. Quite successfully. Sony basically fine-tuned the sensor and imaging pipeline technology in order to help you fill up memory cards much more quickly, in a consumer camera, and with many nearly identical frames. Just like video.

Don't get me wrong. I think global shutters are, in theory, a great idea. They solve some problems. But whether they are the problems we needed to solve is yet to be determined. Is a super high frame rate a good thing? Maybe, but maybe it creates a worse problem by allowing one to generate so many nearly identical files that memory cards quickly fill up, hard drives get overwhelmed and editing time extends egregiously which cuts down on time for human enjoyment. 

Here's a prediction: As soon as global shutters trickle down to affordable, consumer digital cameras, and the "feature" of an "endless frame rate" arrives with them software companies will almost immediately come out with "AI" software that learns your taste in photographs and automatically winnows down your take in a folder. Effectively homogenizing your vision based on what you already did in the past. Work that falls outside your software's learned "taste" parameters gets dumped. Even if it's something you thought to try in a new way. The software will require faster processors and bigger, faster SSDs to operate. In one camera purchase you've created a new need to upgrade vital parts of your computer and your image processing. 

A fact check: Loss of quantum efficiency. Global Shutter sensors can't currently take advantage of BSI technology and depend on older semiconductor tech. Current sensors used for global shutter photography are between one and two stops less efficient which equals one or two stops more noise. 

And then there is the engineering workaround to delivering speed; and speed is what lies at the base of a global shutter implementation. Each file that comes off a sensor; each frame, must be processed by the camera. Hundred thousand dollar movie cameras get around the need to process their files in camera by dumping all the raw information off the sensor and directly into large scale, high speed memory. Super fast SSDs. The raw results (flat, dark, low saturation, etc.) are only made "visible" and workable in post production. Or, in movie cameras, review outputs that have their own adjustable Log profiles.

Current users of high end still cameras have been spoiled. With current frame rates from mechanical shutters cameras have time to take raw data and profile with white balance settings, contrast, saturation and other settings in order to make a pleasing and (hopefully) representative smaller file to delivery to your camera's rear screen or EVF for your immediate viewing or preview and review. The files have been profiled, your camera settings incorporated, etc. It happens to every frame that comes through your camera. Otherwise you couldn't really make much of an evaluation when reviewing the images on your camera screen. 

But here's what is almost never mentioned about cameras and speed, it's the compromises between the throughput of the camera and the amount of time and processing power being lavished on each frame. In order to give you the faster frame rates that many desire something has to be streamlined. To keep costs down parts in the camera (sub processors, main processors, GPUs, etc.) have to be evaluated and compromises have to be made to meet budgets. You could have better color and lower noise out of current sensors if you were willing to pay in terms of battery use, overall cost and increased camera body size (to handle thermal issues...) but too many consumers only see the top level specs. Those are resolution, frame rate and PRICE. 

Price being the ultimate "deal killer". But also the compromises required to hit a price point have a direct effect on image quality. As far as speed goes, all else being equal, the faster you pull frames through a camera's pipeline the less time the camera's working guts have to apply processing to each image. If cost and frame rate are fixed conditions for a camera (to hit the all important price point) then the maker cuts cost in the invisible to consumers areas. They can take a slower imaging processor (the unit that applies corrections and writes output data after files come off the sensor) and reduce the number and/or complexity of the operations the imaging processor undertakes. Do you wonder why very high end Phase One cameras work in the realm of 16 bits while many popular Sony full frame cameras work in the pedestrian realm of 12 bits? It's because churning out highly detailed and data dense 16 bit files requires more (and more expensive) parts and processing. It's also a reason why cameras with very high degrees of color discrimination process files at a slower speed than the one's which paint files with a broad and not very discriminating "brush." 

Color discrimination is the process of breaking file's colors into finer and finer differentiations of tone and hue. The finer the color discrimination the more accurate and nuanced the color coming out of the camera. Less color discrimination and you get a less accurate representations the colors in your images. Would you personally rather have more speed or more color discrimination, the ability to work with files that have higher bit depths, and files in which noise is treated with a scalpel instead of a sledge hammer?

Granted, faster and faster processors will narrow the gap. But only if the makers of cameras earmark the speed increases for file quality over speed and throughput. 

So, yes, the new camera with the global shutter from Sony is an engineering marvel but like any camera it's host to a number of compromises. Higher noise, vis-a-vis current top line 24 megapixel BSI sensors. Lower dynamic range. And almost certainly a processing pipeline that includes 12 bit processing as the default for all raw files. But you do have the nice features of being about to shoot with flash at any shutter speed and the ability to use super high shutter speeds. But with much more limited dynamic range.

Oh, and I almost forgot, the ability to fill a 256 Gigabyte memory card in the blink of an eye. 

Processing. As in most computer based endeavors how processing power is used is a continual trade off between consumer candy features (speed) and real, state of the art image quality. Just sayin'

If you are heading to the Olympics next year to shoot still images for Sport Illustrated or Obscure Sports Quarterly and you are horribly unsure of your skill, timing, etc. A new camera with a global sensor might be just what the editor ordered. Hold the shutter button down long enough and you'll have something for A.I. image selectors to choose from. Every new technology that trickles down into photography has some  positive use case, but that's separate from everyday value to most photographers. 

I'm sure the new Sony A9III is a miracle of sorts. But every photographic miracle comes with some sort of balancing compromise. Old saying.....there's no free lunch. 



30 comments:

  1. Very interesting. I had no idea of all those tradeoffs and disadvantages of GS technology. All you ever hear otherwise is what a wonderful thing it will be. Thanks for the rundown.
    Dick

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  2. I can see the future! I'll dump all my Treasuries and invest the money in SanDisk, Micron, and all the other memory card makers.

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  3. Where is the link to B&H? I need a global shutter right away. Gotta have it for my landscape photography. Will it work on a tripod?

    R.A.

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  4. What GS???? Do I need it for combat photography or medical photography? Or will my Leica M4-2 do the job?

    I'm confused..............but there again I'm 72......and still shooting with a Leica M4-2 and a Voigtländer 35mm

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  5. Fascinating analysis Mt.T. Learned a whole lot. Think I'll stick to my snail pace Fujis for a while yet.

    Wonder if Apple has any plans to stick a GS in their Mac Mini ... LOOK MA!!! IT CAN FLY!!!

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  6. From what I've read it's 14-bit readout even in 120fps mode. 6GB/second of data. But yes, DR and noise take a hit to enable these abilities. I'm a portrait guy, this is the last thing I need - but it's always interesting to watch the tech advance.

    - Travis

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  7. You covered my thoughts and more. I bought the A7rv for megapixels (I like cropping to square format) with the added benefit of pretty accurate autofocus for most people and wildlife (the distinction is subjective) photography, but I have to turn off the subject detection for a substantial number of photos so that I can choose what is in focus. I do not always want my camera to jump to an eye. Sometimes I like to take a picture of a foot.

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  8. In addition to my M43 and FF digital cameras, I sometimes shoot large format 5x7 and 11x14. No question - I need that global shutter for large format as well!

    Even my Olympus E-M1 Mark II is TOO SO O O O slow! Its maximum frame rate is a paltry 15 frames per second with the mechanical shutter and 60 frames per second with the electronic shutter. Each a masterpiece, of course, that I absolutely must print large.

    Does BH have a consumer-priced 5x7 or 11x14 GS sensor in stock yet?

    Seriously, global shutter may someday be a useful technology, but I'll wait until it's routine, practical, and readily affordable. It doesn't exactly upend photography.

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  9. The only feature of the global shutter that really toots my whistle is the ability to synch flash at higher shutter speeds. But I had that 50 years ago with flashbulbs.

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  10. someone was talking about this being good for "long exposures" made of lots of short exposures composited

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  11. Kirk: If you are heading to the Olympics next year to shoot still images for Sport Illustrated or Obscure Sports Quarterly and you are horribly unsure of your skill, timing, etc. A new camera with a global sensor might be just what the editor ordered. Hold the shutter button down long enough and you'll have something for A.I. image selectors to choose from.

    Actually, this is what you need.

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  12. Probably the best photo blog post I've read anywhere in quite a while. Timely, on topic, very well written, and thought provoking. Thank you.

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  13. If I want a video camera I will buy a video camera.

    Eric

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  14. I got the Dodgeball reference. And I agree with the central philosophical point made by the movie: if you can dodge a wrench, you can dodge a ball.

    This blog entry filled my technology news quota for the next month and a half.

    I think some somebody might need a global shutter. I don't.

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  15. My Olympus E-M II had the perfect moment sports action capture feature available years ago. Just hold the shutter release half-way and the camera goes into high frame rate mode, retaining the last second or so of photos so that you can choose the best action shot. I assume that other medium-high end cameras also have such a feature, even without Global Shudder.

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  16. You nailed it. Thanks.

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  17. Very cool article. Thank you, Kirk.

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  18. After looking at several of the raving reviews from the usual suspects, I was so happy and relieved to read you clear and cogent take on the Global Shutter hysteria. Thanks for putting things in their proper context.

    Rene

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  19. 180 years of photography down the drain.

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  20. Thank you for a sensible explanation. And one I can understand.
    Just want to say I feel seriously underwhelmed by the idea of owning a GS.

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  21. So shocked and awed by the Sony Global Shutter Announcement that I have been unable to get out of bed (except for swim practice). I asked around. Everyone is getting one. Even my lawn guy and the cashier I spoke with at Trader Joe's. I don't see how Sony will ever meet demand....

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  22. Let me ponder this global shutter stuff. When I click the leaf shutter on my Hasselblad or Rolleiflex, the blades open symmetrically from the center. Is that global? The film receives photons. Is that quantum readout? GS rendered these "primitive" cameras useless?

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  23. From the Editing Department, Online Publications, Kirk Tuck Enterprises:

    Mr. Tuck,

    We find ourselves once again writing you to inform you of an egregious grammatical error in your recent online post regarding Global Shutters. As we have previously stated, if you cannot improve the quality of your grammar we will have to consider once again suspending your direct-posting privileges. As you know, the publishing standards of this online empire are quite high and we cannot have one rouge writer bringing down the entire house.

    Please note the use of a capital "A" after the abbreviation of "etcetera". Very disappointing indeed.

    "If you are heading to the Olympics next year to shoot still images for Sport Illustrated or Obscure Sports Quarterly and you are horribly unsure of your skill, timing, etc. A new camera with a global sensor might be just what the editor ordered."

    Sincerely,
    The Editor's Desk

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  24. Severely chastened. I'll do better next time.

    Given the grievous emotional damage this may have caused I've instructed VSL accounting to refund your October, platinum level dues.

    The management.

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  25. Dear Editorial Desk:

    Your post chastising Mr. Tuck stated that he was a "rouge" writer. We can only assume that you meant a "rogue" writer, but your "Sarah-Palinesque" error has evident implications for your over-reliance upon "auto-error" spelling and grammatical abilities as well as your political stance.

    Hence, in accordance with prevailing standards, you are hereby suspended.

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  26. Now Joe, I wasn't going to mention that. But since you did ......... let's not suspend our faithful and well meaning compatriot. We'll just call it a "first strike."

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  27. - just keeping the ball in the air, in pure jest.

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  28. Me too! My response was definitely meant tongue in cheek. As was Pixtorials (I assume).

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  29. Rouge, as in colorful. Yeah, let's go with that.

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