Damian Dinning Explains the Mechanical Shutter to MNB

| June 8, 2013 | 70 Replies

Screen Shot 2013-06-08 at 18.13.29

 

Damian’s commented on Ali’s post regarding the mechanical shutter. Thanks Damian for your insights!

Screen Shot 2013-06-08 at 18.35.00http://mynokiablog.com/2013/06/07/the-benefiet-of-having-a-mechanical-shutter/comment-page-1/#comment-887748

Hi everyone, there are so few factually correct statements in the original piece or related comments (no disrespect intended) I felt compelled to help explain. :)

Please note, my comments are ONLY addressing the general topic of mechanical shutters – no more.

Keeping it simple, the main reason for fitting mechanical shutters is for use with xenon flash. Typically CMOS sensors read light across the sensor from left to right and top to bottom. The time each pixel is ‘read’ is the effective shutter speed. This is OK in most cases and OK with LED flash as the light is effectively constant/continuous. LED flash in most cases being the equivalent of turning on a torch before the exposure and turning it off after the exposure has been made, effectively increasing the amount of light in the scene more or less for the duration of the picture.

In the case of xenon, the flash fires a very short ‘pulse’ of light. This pulse can be as short as approximately 1/25,000 (hence why xenon can freeze high speed movement). With a typical CMOS sensor the time difference between the 1st pixel being ‘read’ and the last is greater than this time. The result would be some pixels would be correctly exposed whilst others would be dark or even potentially black. To overcome this, the pixels are effectively read all at the same time. But to achieve this all pixels are turned on, the shutter opens, the flash fires, the shutter closes and the pixels turned off. And that’s why typically mechanical shutters have been needed in products such as n8, n82, n808. In some cases some latest generation sensors can read all their pixels at very high speed (note: again don’t ask me to comment on speculation or rumour) allowing xenon to be used. In some cases e.g. Nikon 1 series these later generation sensors are allowing for electronic shutters which can provide potential advantages in high frame rate scenarios which mechanical shutters would not be suitable for.

In some cases a hybrid approach maybe used e.g. a SE product of a few years back which featured xenon only used the mechanical shutter for flash but not other situations, which meant in that case it didn’t provide the following potential advantage….

With mechanical shutters, because the pixels are effectively read all at the same time it overcomes the motion skew effect which can typically occur with CMOS sensors due to the time difference between the first and last pixels being read. As the read time from CMOS sensors is increasing (shorter read times) this is becoming less of an issue in some cases.

Mechanical shutters do require additional space, there are no space advantages to them.

As for dust protection there is some theoretical advantage to them but in practice (at least in my experience) I have seen dust penetration in all cameras, there is a fundamental limit to what can be done to prevent dust penetration.

Hope that clarifies things.

Cheers Janne for the heads up

Category: Nokia

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  1. Adnan says:

    Damian you’re a gentleman and a scholar

      • sunnyvale says:

        I don’t get it, does Damian lurk around here? I assume he just visits another website, and they were linking back to the source, which is mnb.

        Haha, or one of you folks when harrasing him with questions?

        • Janne says:

          I think Damian is just human like us.

          Can’t stay way from the great MNB.

          Even when it would be smarter to… ;)

          • sunnyvale says:

            I think you meant “even when it would be smarter not to” :)

            Haha I know he’s a human, just like us and I don’t discard the possibility of him being an avid silent MNB reader.

            Perhaps he posts under a different alias, since letting people know that he’s Damian, they will start pestering him with questions about rumors and whatnot.

  2. Mendax says:

    Glad to see Daz isn’t far from the community, and is keeping his ear close to the ground.

  3. chris wayne says:

    Oh i miss my black N82 from 2008 T_T

  4. twig says:

    Did I detect something about a Nokia shoulder bag with big Nokia printed on the side in the dust comment or am I extrapolating? 😉

  5. arts says:

    So… We can look at the people who commented on that article and safely ignore their future comments? Im game! ;)

    • Werner Ruotsalainen says:

      Well, actually, there have been several to-the-point and technically flawless comments in there.

      For example from me – long before Damian’s comment, I had also described in one of my comments why mechanical shutters are to be preferred when using Xenon flash (see my post at June 7, 2013 at 21:14 GMT).

      That is, not all comments there were inaccurate.

      • johan says:

        Don’t feel too bad – I am sure Damian Dinning saw your post and approved of it’s content. Many other posts, though, were bizarre.

      • arts says:

        dont worry, i did try to find out which one kinda matched what damian said. =D

    • twig says:

      +1 ,lol 😊😃😄

      ot…Microsoft has a new program in the U.S. for people to donate to college students towards their new Win8 tablet or laptop,etc. Tablet as in “perfect timing for a Nokia tablet” in the U.S. A little cross merchandising with the 925? My Surface RT locked up and will not swipe because its not a Nokia,period.

  6. Doug says:

    Damian > Elop

  7. Me says:

    Damian Dinning respect.

  8. dss says:

    I think that Damian was a big asset to Nokia.

    He could explain complicated technology in a very accessible manner, such as the post above, and I think that is essential if you want your consumers to understand what they are buying.

    Like this video.. it captures everything the Phase 1 system is in 8 mins.

    http://www.youtube.com/watch?v=ZheH4PjEows

    • Janne says:

      Being a great communicator is indeed one of Damian’s strong suits.

      From an outsiders perspective it is hard to say what his actual and eventual role at Nokia’s imaging was, but then that is the problem with outside observation of any Nokia personnel we make here. We mostly know them from their talks and presentations. Actions, be they good or bad, significant or insignificant, remain often shrouded.

  9. muhs says:

    heyy, i hope someone asks him from the authors or anyone about the lumia 928…… the lumia 928 features a xenon flash but doesn’t have a mechanical shutter so does this mean the 928 features a sensor similar to the Nikon he mentioned or what ??

    • muhs says:

      i also assume the SE he mentioned is the the sony ericsson K850i as as far as i know its the only SE with a mechanical shutter !!

    • rez says:

      This is a good question.

      • Werner Ruotsalainen says:

        Not knowing the inner specs of the 928′s camera module, I can only guess so my conclusion may be flawed.

        The 928 may lack the mechanical shutter (MS) because it has a fast sensor quick enough to read all its pixels during the Xenon flash’s illuminating the subject.

        As I’ve pointed out in my previous posts, the 41 MP 808 has a VERY fast sensor. It allows for a complete (!) sensor read at least 30 times a second, which means it’s at least an order faster than the sensor in, say, the iPhone 5. (I’ve been written several video camera utilities for all iPhone models stating with the 3GS so I know their sensor performance. A full 8MPixel sensor reading takes about 1/19s on the latest, fastest iPhone 5 – and we’re speaking of five times less pixels than in the 808. That is, there’s almost an order of magnitude speed difference between the 808 and the iPhone 5.)

        Assuming Nokia uses the same sensor tech as in the 808 with one-fifth the number of pixels, the reading of the entire sensor can be done by 1/(30*5) sec, that is, 1/150sec. And that’s the worst scenario based on my assumption the 808′s sensor can be sampled only 30 times a second and not faster.

        1/150 sec is pretty close to the entire illumination duration of particularly the slower Xenon flashes.

        That is, assuming the sensor is fast BECAUSE it uses the same tech as the 808 AND because it only has 8MP, it’s entirely possible they could just use electronic shutter and didn’t need to use MS at all, at least not for Xenon flashing.

  10. viipottaja says:

    Even I understood what Damian said, and that’s saying something!

  11. Symbian was not responsibe for everything says:

    That was a great post from Damian.

    About that another matter about 808. People seem to want to respect authorities. Even while that makes no sense.

  12. Symbian was not responsibe for everything says:

    In the world of photography, we are one or half step behind the display technology.

    Mechanical shutter in digital photography is like watching a film in a movie theatre.

    Digital shutter is like watching an old fashion television. Not the flat one but those old ones some people don’t even remember.

    Flat televisions are yet to really happen in digital photography.

    • Werner Ruotsalainen says:

      “You can’t beat the laws of physics / optics”. Unfortunately. Shooting stills / videos isn’t covered by Moore’s law because one just can’t tell photons “hey, I need orders of magnitude more / less of you to make the best possible image”. In this regard, it’s more like cars and space travel.

      • Symbian was not responsibe for everything says:

        What are you talking about?

        I was talking about shutters.

        Not about how thick or thin phones are.

        • Werner Ruotsalainen says:

          Well, your message was quite cryptic. I though you had referred to capturing light being lagging behind reproducing already-captured light on TV screens.

          The laws of physics constrain the former much more than the latter, which results in, among other things, using rather large sensors – this is what I referred to.

          • Symbian was not responsibe for everything says:

            I was referring to how one pixel is illuminated in the sensor or in the display.

            In the third phase on the displays the flickering was gone, introduced to us in the base two by the beam on those old displays.

            The size of the displays or the size of cameras has nothing to do with this.

            • Werner Ruotsalainen says:

              OIC, so, you meant “first was going to the cinema, then came the CRT and, finally, the TFT / plasma”?

              Well, cinema is still alive and kicking – and has always, any time in the past, delivered way better image quality than any home TV technology. (Starting with the Nipkow TV’s, continuing with the first CRT units, and even TFT’s of today – a decent 3D 4k+ cinema delivers far better experience.)

              This is why your reasoning isn’t really applicable to the development of technology in general.

              • Symbian was not responsibe for everything says:

                Well, yes, that was that I had in mind.

                But I wasn’t really addressing the image quality or any technology replacing the other. Just how pixels were illuminated and the order how those illumination technologies became popular once they were invented.

      • Symbian was not responsibe for everything says:

        I wasn’t talking about this, but maybe I should mention it because even the MNB team had their own reference to science fiction in the blog post.

        In a very distant future, maybe the entire back panel of the mobile phone or a similar device, could be used to capture light in an effort to create the ultimate photo. Assuming those devices have back panels.

        I guess I don’t have to describe that kind of technology any further because it’s definitely not going to be here any time soon, in the consumer products. But it’s a funny concept.

  13. Mario says:

    The master in action. Thanks, Damian!

  14. xconomicron says:

    So does the mechanical shutter reduce the effect of a rolling shutter? That camera that was filming the EOS demo, definitely suffered from a rolling shutter.

    • Werner Ruotsalainen says:

      It does when it IS being used – that is, strictly when taking stills. Some cameras have sensors that can be fully read very slowly (example: Pana GH3; see the article I linked to in the prev. article’s comment section), some much faster (e.g., the Nokia 808 and, I bet, this sensor too) and some, I bet, even faster (e.g., Nikon System 1 sensors). (Of course, the 808 has far more pixels than the Nikon 1; should the latter have more pixels, the 808 could easily become faster on the whole. Dunno.)

      Mechanical shutter can NOT be used when shooting video; this is why videos (shot by electronic shutter) are much more prone to skewing (rolling shutter) than stills (made by mechanical shutter).

  15. Drangons' Tear says:

    notice how as soon as DD left Nokia and they killed they ONLY OS THAT WAS COMPATIBLE with the Sensor hardware…they’ve been running around like headless chickens….cause elop fire everyone and hired people that don’t know WTF they are doing

  16. sholen143 says:

    Symbian was not responsible for everything
    Because there were a variety of mobiles running Symbian..means variety odd cameras different form factors.. even now world’s top two best cameras run Symbian (& yet they call it dead OS)..

    • Viipottaja says:

      AAS recent test put Samsung G S4 on number two spot though.

    • JGrove303 says:

      Bloggers call it dead. We’ll say it’s in a state of maintenance.

      I agree, my N8-00 will outshoot my 920 any DAY, but when the Sun goes down, it’s Lumia time!

      I find it disturbing that so many Symbian Faithful are so against Nokia that they take a stab any chance they can at WP and what Nokia is able to accomplish with it. I dont care why. Hitler had his reasons, too.

      What, are there really S60v3 holdouts that can’t accept progression?

      Get behind Big Blue or go kick rocks.

    • Symbian was not responsibe for everything says:

      That would be nice if Nokia was selling only cameras.

      Unfortunately Symbian was not suitable for modern smartphones and that pretty much resulted Nokia’s reputation collapsing when they tried to do that.

  17. sumedh says:

    A very good read.
    Thank you for the info.

  18. sailfishos rocks says:

    is he so free at his new company?

    Do not know why he joined non-camera related job

  19. @N9Andy says:

    I love how Daz refers to the 808 as the “n808″. I actually would like the NSeries tag on the 808 PureView tbh. NSeries always said to me: top Nokia quality, which the 808 is of course.

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