Heat issues of 32MP 5D Mark III CMOS could mean video mode sacrificed


Canon 5D Mark III

EOSHD is concerned that camera manufacturers are beginning to experience heat issues with their CMOS sensors as megapixel counts increase.

As CMOS technology allows for greater speed, offering ever faster frame rates, the technology is also being pushed towards higher pixel counts, with Sony’s upcoming A77 said to feature 24MP and the 5D Mark III 32MP.

Although Sony have worked hard to increase the energy efficiency of their Exmor HD sensor, this progress is being undone by significant increases in resolution and frame rates. Even their compact camera the HX9v now features 16MP and 60fps progressive in full HD / live view mode. The GH2 scans the sensor at 120fps to speed up contrast detect AF. The older Sony A55 had overheating problems which limited video to just 9 mins with sensor-shift stabilisation enabled. The Canon 7D’s overheating warning crops up every now and again, and that is on a 18MP line skipping sensor at 24p. The 5D Mark III is expected to feature 32MP.

Heat build up is a real issue and poses a real threat to our high expectation of video on the Canon 5D Mark III.

Ichiro Kitao of Panasonic is particularly worried. Their flagship product, the GH2, has an emphasis on video.

“If we continue to raise the resolution it becomes very difficult to offer high quality video, due to the heat problem.”

Not only do higher megapixel counts reduce low light performance by reducing the size of the pixels themselves, heat build up increases noise when the camera is used for live view or video.

Personally I think the 5D Mark III should be split into two lines, the 5Ds and 5D.

The 5Ds would lack video and be designed for photographic studios where 32MP resolution would be useful for enlargement and cropping. It would also replace the rather redundant 1DS series in Canon’s line-up and retail for a higher price than the standard 5D Mark III.

For the rest of us the 5D Mark III would take the philosophy that Nikon applied to the D3S but with the world beating video mode we’ve come to expect from Canon.

12MP would allow class leading high ISO performance and video without line skipping or heat build up issues.

About Author

British filmmaker and editor of EOSHD, Andrew works in Berlin on his own self funded filmmaking and video projects.


  1. Calm down dear!
    Pixel density on a 32mp on a full frame is equivelent to around 12mp on a APS C that why you are less likely to get over heating with a 21mp 5DMk2 than a 18mp 7D. Together with general improvement in Digic V heat problem with a 32mp 5DMk3 is a none issue.

  2. gene_can_sing on

    I seriously doubt the 5D3 will not have video mode. That’s one of the MAIN reasons why the 5D2 sold so well. Everyone I know (lots of people) bought the 5D2 for the video, but I work in TV. Digic 5, after 4 very long years should be advanced enough to handle the heat, or else it’s basically a failure.

    They just need to make 2 lines, one 5D3 for video and one for Stills. Because you can’t make both camps happy. Maybe limit the video version to 12 megapixels for stills and I will be happy.

    Plus, it’s the only full frame video camera and that’s a huge selling point for the 5D line.

    But a video optimized 5D3 with 4:2:2 and possibly RAW to recorder, will cost a lot more than the current 2.6K price. But it will be worth it, if it’s good.

    Mostly, it just needs to come out SOON!!!!!!

  3. I think it would be wonderful if Canon would split not only the 5D line, but the 7D line as well in the future for filmmakers and video enthusiasts. I just hope that they would charge over 1K extra for optimized video, but (sigh) who knows?

    And I agree with gene. In a way, I respect Canon for keeping things close to the chest, but I WANT TO KNOW WHEN THE BLASTED FLAGSHIP IS COMING OUT AND WHAT FEATURES IT IS GOING TO HAVE!!! :)

  4. I’m sorry but you misunderstand. It’s not about density it’s about the amount of data the sensor is producing per second, and the amount of data the image processor has to cope with as well.

  5. There are some aspects of the camera that are better suited to good high ISO and good video. None of them involve higher megapixel counts than 12MP.

    Surely the typical level of user the 5D line is aimed at is beyond the megapixel war, and sees right through it. Right Canon?

  6. Canon has been in the market for too long to make the wrong move with this one. They can make big MP dSLRs with video. Digic V will do it, even 2 Digic IV.

  7. Still don’t think it will be an issue. Overheating issue as far as I know is less of a problem with the 5DMk2 and the 7D.

  8. Heat is definitely a concern in my experience – even with the GH1 – I have had two GH1s shut down when left recording for long periods, set up as static cameras filming a Hindu wedding (in a fairly hot environment, admittedly, though not tropical temperatures). And I experienced the same problem last night at a wedding reception – one camera switched off after about 40 minutes. In a more comfortable environment (ambient temperature about 60F/16C) both my GH1s will record continuously until the battery runs flat – about three hours.

    So the manufacturers are right to be concerned about heat build-up.

  9. 5D3 wishlist:
    – 12MP
    – Clean HDMI
    – Digital Sensor Cropping Zoom from 1.0x-3.0x (Allows for a APS-C comparable FOV and then some, without losing resolution)
    – 1080p60 or higher & possibly 720p120 or higher
    – Seamless Auto restart after 4GB file cap, so everyone who shoots with locked off cameras can stop complaining.

    Wild Wishlist
    – Undercranking capability, or just dynamic frame rate control. This could also be at higher resolution then 1080p. Gives you a cross over range between time lapse and video.
    – HDR and/or Raw video.

  10. Meh, I’m not thinking it’ll be all that critical. Better designing of the both the sensor and camera body should be able to accommodate reasonable amounts of increased heat. Computer makers managed to do it with laptops, I don’t see why camera makers wouldn’t be able to likewise innovate. If they want to sell more cameras they’ll find a way to deal with it.

  11. I think they know full well that if they fail to implement video in their latest 5D model it makes it a lot less desirable. I know of over 30 people who own the 5D purely for video. They all want to see improved video featured in the 5D Mark |||.

    I for one hope they implement a better processor to match its competitors.

  12. “- Seamless Auto restart after 4GB file cap, so everyone who shoots with locked off cameras can stop complaining”

    +1 +1 +1 +1 +1

  13. Sure they’ll be able to do it. But to what standard? The Panasonic guy says more megapixels make it hard to implement good video. If the 5D Mark 3 is to have 32MP, I doubt it will scale cleanly. It will probably be another moire mess of line skipping tricks.

  14. Oh it’ll be a complete and utter disappointment if the 5D3 would still be resorting to the same tired bin-and-skip routine now seen on all their VDSLRs, they’ve been milking it for 3 years now. Panasonic has done it right since day one (at least as far as the sensor design is concerned) and Sony seems to be getting better at it, Canon can’t afford to sit still

  15. I think it would be best if they introduced a camera body with video in mind, it doesn’t have to be an SLR. Keep the EF mount, keep the sensor size, but maybe one optimized for 1080p (8.3Mpx 16:9 sensor would probably be the best for quality (that allows for 1 red, 1 blue and 2 green photo sites per video pixel), the mirror doesn’t have to stay, add a headphone jack, better audio recording controls, maybe even XLR audio inputs.

  16. it will cost too much and the whole idea about cheap access for indie film makers is lost. May as well get a camcorder like the FS100

    Remember too, there is still the issue of audio and the 12 minute running time that won’t be changed, unless you classify it as a camcorder and up goes the price with a different tax bracket

    Who needs 32mp anyway? 12 mp and a decent low pass filter is fine but the issues mentioned need to be addressed

Leave A Reply