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See A Shutter Mechanism Movement Captured At 10,000 FPS | Eye Opening

By Kishore Sawh on February 3rd 2015

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It’s my belief, that if you want to be able to manipulate your tools to the best of your ability, then you should have some good understanding of how they work. This applies to any number of things, from cars to cameras.

I remember learning to drive stick as a young teen, and my very particular brain, that likes to know everything about a process before beginning, couldn’t quite wrap my head around the idea of balancing the clutch and gas pedal, or double de-clutching. What was I trying to balance? Why? Should the pedal movements be equal? Why does double de-clutching require a pump of the throttle in neutral or with clutch depressed before re-engaging?

Explanations from my uncles and grandfather helped and I could drive, but it wasn’t until actually seeing a transmission diagram, and then in real life, did I fully understand what was going on, and it made my ability to drive that much better. I understood the limits of the car, to some extent, which meant I could control it better.

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The same sort of thing, I believe, works for cameras. 

Anyone can click the shutter release button of an SLR and get a basic understanding of what’s happening, and sort of envision it in our minds. We know the mirror locks up, the shutter opens, light hits the sensor/film, and then shutter closes, and the mirror returns. Easy. It begins to change and matter a bit more when you’re getting into high shutter speeds, and I’ve often found the need for a physical demonstration with paper when explaining high flash sync capabilities.

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Once you pass a certain shutter speed, the shutter doesn’t behave the same way by fully opening then closing. Instead, one part goes down and another part follows closely behind it, leaving an open sliver where light can get through to the sensor, a little at a time.. That’s the only way to achieve those really high 1/4000 and such shutter speeds. In the video below done by The Slow Mo Guys, you can see exactly what I’m talking about, and really get an understanding of how your shutter works. They film the shutter mechanism of their trusty Canon 7D at various speed with a Phantom 4k at 10,000 frames per second.

[REWIND: Canon 7D mark II, A Wedding Photographer’s Perspective Review]

You’ll start to understand the limits of high speed sync, why we have rolling shutter effects in video, and with the speed the camera locks and slaps into place, you’ll see why sometimes it’s really beneficial to manually lock up your camera before taking the shot.

You can find out more from The Slow Mo Guys on their YouTube channel.

About

Kishore is, among other things, the Editor-In-Chief at SLR Lounge. A photographer and writer based in Miami, he can often be found at dog parks, and airports in London and Toronto. He is also a tremendous fan of flossing and the happiest guy around when the company’s good.

Q&A Discussions

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  1. Murray Severn

    Very interesting indeed!

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  2. Jason Boa

    Wow – very techy

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  3. Peter Nord

    I take the back off a Speed Graphic to show my students the slit of the focal plane shutter in action. So big and slow it’s easy to get the idea of the moving slit. Those were the good old days when real flash bulbs made such a soul satisfying pop.

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  4. Tosh Cuellar

    Thanks for sharing, very very cool, I thought I understood, and I get the mechanics of it, but still wasn’t what I expected exactly.

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  5. Kyle Stauffer

    Question 1: Is there any more “freeze” in action over 1/1000 of a second? By watching in high speed, it appears that the rate at which the shutter comes down between 1/1000 and 1/8000 is exactly the same and only the gap between the top and bottom curtain change ever so slightly. I understand that this would change exposure, but one would think the curtain speed would need to change to effectively be freezing faster action.

    Question 2: If the sensor reads from the top down and at changing durations, why does it need a curtain that simply follows it’s “read” path?

    I always wondered why more effort wasn’t put into global sensors (CCD) rather than CMOS due to the many benefits of global such as high speed flash sync or long exposure. One would think that the low light capability of CCD could be improved in today’s technology.

    Please excuse my ignorance on this subject. This is all very fascinating and somewhat new to me to wrap my head around.

    Thanks,
    Kyle

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  6. Chet Meyerson

    If you ever wondered why you should lock up the mirror for the sharpest images, this will show you why. Watch that mirror bounce all over the place when it goes up. Also electronic first curtain (that the once that comes down first) will even increase sharpness more. Mirror and 2nd curtain bounce doesn’t matter on the down motion, the exposure is already over. Thanks for the high speed videos.

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  7. Basit Zargar

    awesome

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  8. Barry Cunningham

    Great video.
    Faster shutter speeds really need to be measured by 2 times:
    1. The length of time each pixel is exposed. This is the speed the camera tells you and is what you need to know to determine how much light is falling on your sensor.
    2. The length of time it takes to expose every pixel in the frame. As clearly seen in the video, this may be a much longer time when the size of the slit is small. This is what you need to know to determine what motion or fast events (e.g., flash) occur during your exposure.

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  9. David Hall

    Awesome video guys… thanks for sharing this.

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  10. aaron febbo

    i will admit i did not know that thats how the shutter worked. Is that embarrassing ? I know and understand the mechanics but i guess it was just different seeing it in slow motion

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    • Kishore Sawh

      Don’t be embarrassed Aaron, you’re not alone there even if few others admit it. Try as i might to explain it using sheets of paper, this is far better and what I’ll be directing people to from now. Glad it helped.

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    • aaron febbo

      yeah i know the mechanics of it but how it works with different shutter speeds is what really made the ah ha moment haha. I originally learned about the shutter by sticking my finger in an old slr camera and firing it on bulb mode.

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