Teardowns and Disassembly

5D III Strip Tease

Published April 11, 2012

The best worst thing happened today: a nearly new Canon 5D Mk III came back from rental with a loose screw rattling around inside. We had to decide if it went back to Canon or if we should go looking for the screw ourselves. That’s a tough decision. So we thought about it for a while. Until Tyler and Drew went to lunch. Then we decided it had to be handled in-house. Since we had to open it up to find the screw (there really was a loose screw, we swear) it seemed a good idea to take a few pictures along the way. In case we needed documentation to help with the reassembly. Yeah, that’s it. We were being extra careful to make sure we could get it back together. We weren’t doing this just to take a look inside at all.

But not being total idiots, we didn’t completely take it apart like we did with the NEX or D7000 camera. So this is only a strip-tease, not a strip down. But it’s still fun (and educational too!!!). One thing that is readily apparent: I made the comment when the camera first came out that this could well have been named the 6D, it was really different than the 5DII. Nobody else seems to think so, but looking inside confirms what I thought: inside this camera is largely redesigned and it’s one of those where I want to compliment the engineers. This camera is beautiful inside, logically laid out and well built.

The Usual Disclaimer Stuff

First things first: if your camera is in one piece, then leave it alone. We’re semi-trained, semi-professionals with another 80 of these on the shelf. If we screw it up, we’ll only have 79 left, which is probably less critical than if you screw up the only one you have and then need to ‘splain to your wife why you have to buy a new camera. (And for those of you wondering if we got in trouble for doing this – no, we had it completely reassembled before Tyler and Drew got back from lunch. They’ll never know about it.)

So Let’s Have a Look!

Aaron started the disassembly while I went looking for a macro lens, so by the time I got back he’d already peeled off the grips, removed 20 odd screws, and opened the case  (Aaron just likes to show off sometimes). Differences from the 5D II are immediately apparent: there is only a single flex attaching the back assembly to the main board, and one flex and a wire harness from the top assembly. The circuit boards and flexes for both the camera body and back are covered with black rubberized sticky plastic, protecting things inside (and possibly adding some electrical shielding). I haven’t seen this on other cameras, it’s a very reassuring thing (and may explain why the loose screw didn’t short anything out).

Looking more closely at the back, several other changes are apparent. All of the flexes take short, direct routes to where they are going. No long winding flexes stuck down hither on yon. There are also a lot more of the robust ‘plug-in’ type connectors and fewer of the ‘slide-and-lever-lock’ which (I know from unfortunate experience) are rather delicate. There are also several places where wiring harnesses (look at the upper left corner of the main circuit board) are used rather than flexes. They’re certainly sturdier and (I assume) provide better electrical insulation.

Looking at the front of the camera, it’s again notable how clean and organized everything is. No long wires running here and there. Wire pairs are nicely braided and there are grooves and hooks in the plastic to keep them in place. That’s a nice touch that you don’t often see.

Another minor, but very nice touch that shows how carefully this design was thought out: the battery latch is right at the front of the compartment as an easily replaced screwed in assembly. On other cameras (including the 5D II) it requires major disassembly to replace a broken battery latch, which is a common repair. This one can be done in minutes.


Looking at the top, there’s nothing remarkable except more of the same: everything is neatly laid out in it’s place with minimal wiring and connections.

Going back to the back of the camera, the sticky plastic protective sheet pulls up easily. As an aside it already has shown it’s worth: the loose screw was in the crease along the edge of the plastic sheeting – the sheeting kept it from shorting out anything on the circuit board.


With the sheeting removed you get a really good look at just how well this camera’s electronics are laid out: every flex run is short and direct, insulated wiring harnesses are used in several places, and heavy-duty plug-in connectors are used more frequently than I’ve seen on any other camera.

The difference in connections is obvious in this close up. Slide-in flexes (held up by the forceps) are used in almost every connection in most cameras. The heavy-duty plug in type on the left and thickly insulated wiring harnesses (deeper and between the two connectors) I’ve rarely seen except in this camera and Pro (1D xxx or D xxx) bodies.

You can see another nice touch if you look at the two large flex connectors between the main board on the left, and the smaller board on the right (in the image of the entire back, above). The right board contains the SD card (lifted up, on top in the image below) and CF card slot (underneath). CF pins break frequently and if they can’t be resoldered can require a main circuit board replacement in a 5D II. On the III only the card assembly would require replacement. A very nice touch from an engineer who is thinking about future maintenance as well as the current camera.

A last close-up of the circuit board before we put this thing back together. The Digic 5+ chip is really rather huge. The chip above it is, I believe, DRAM, but I’ve no idea on the other two.

There is probably more goodness to see down deep in this camera. But Tyler and Drew were heading back from lunch, we’d found the missing screw and put it back where it belonged (it was one of 4 holding the card readers in place – the card reader’s were still firmly in place and wouldn’t have missed it but the rattling would have freaked someone out) so we thought it best to get things put back together before anyone noticed we’d taken it apart. It’ll be just our secret.

Ooops, I almost wrote an article without a lame pun. But I know what  you’re thinking: we must have a few screws loose to be opening a 5D III like this.


Roger Cicala


April, 2012

Author: Roger Cicala

I’m Roger and I am the founder of Lensrentals.com. Hailed as one of the optic nerds here, I enjoy shooting collimated light through 30X microscope objectives in my spare time. When I do take real pictures I like using something different: a Medium format, or Pentax K1, or a Sony RX1R.

Posted in Teardowns and Disassembly
  • You’ve turned this into one of the most interesting and entertaining photo-oriented sites on the web. Thanks for another great post, Roger.

  • bluto

    I’ve noticed in the last few colums, you all seem to do quite a bit of repair work. On a given body or lens, how frequently does something require minor repair?

  • Wendy

    I was looking at the upper LCD for clues, it looks fully covered with the black plastic.

    >>Buuuuut, I’ll be there’s another one with something wrong coming around soon.

    Don’t say that!! 🙂

  • Roger Cicala

    Jojo wrote: Did you guys have a chance to look at the top LCD area ? This is would have been a perfect opportunity to determine to cause of the much discussed light leakage. A quick look at the area would determine whether it is a design flaw or manufacturing tolerance.

    AAaaarrrrrgh. We should have done that (and a couple of other things while we were there). We were having so much fun on our big adventure that we didn’t take the time to do some of the practical things we could have. Buuuuut, I’ll be there’s another one with something wrong coming around soon.

  • Nuno

    Roger, I believe you might have a D800 arriving soon with some air molecules inside, perhaps you should take a sneak peak inside to see if you can spot them, you known during a lunch break 😉

    P.S. Thanks for this blog 🙂

  • Jojo

    Did you guys have a chance to look at the top LCD area ? This is would have been a perfect opportunity to determine to cause of the much discussed light leakage. A quick look at the area would determine whether it is a design flaw or manufacturing tolerance.

  • Bob

    I bet one of those new hammers would fix that right up 😛

  • Hahahaha @mike caplan – your post frames the situation quite nicely. I hope no one is too raw from your undistorted humor. I’m definitely glad Roger doesn’t sensor this sort of tangential, yet awesome, post.

  • On the warranty comments, it’s my understanding that as a rental house, Lensrentals doesn’t actually get a camera warranty. So a whole lot less risk to them to fix it themselves. Roger can correct me if I’m wrong on this.


  • Roger Cicala

    Hey Bob,

    We didn’t get down deep in there, but it seemed to be a polymer that the PCBs were screwed into: not really plastic feeling, more like the heavier polymer they use on some of the lenses – I couldn’t say if there was a metal shell under that or not, though.



  • Bob

    Hi Roger,
    Very interesting, indeed it looks neat and tidy and well planned. A question has arisen on one of the dpreview forums, if you look at the mirror box housing, to which the lens mount is attached, and the pentaprism sits on top of, what is it made of. Looks like some kind of polymer/composite from the photos.


  • Thanks for posting all the articles that you do. I hope you get a lot of traffic for it and that it helps your rental business. Love the relaxed writing style and your lame puns.


  • Slav

    Silvio, I don’t think warranty applies to rentals – once a piece of equipment has been out for rental, it’s out of warranty. Or so I think I read.

  • very interesting to see the insides, not sure if I would have the balls to take mine apart…

  • Ben

    So no real weather sealing? Gaskets around the buttons, screens, card doors, switches, etc?

  • I like your DIY approach, but I guess this did void your warranty?

  • Roger Cicala

    Thank you, Jack. I didn’t know that. Appreciate the info.


  • Jack Amano

    A strip tease seems to be a trend of digital cameras!

    Joking aside, I wish Roger would identify the real manufacturer of eletronic parts
    like DIGIC5+ that is really designed and manufactured by Fujitsu.

  • Roger Cicala

    I didn’t see any weather sealing around the input-output circuits, although the rubber covers seem quite snug. The camera is really well put together. But water damage is so permanent . . . . . and so not covered by warranty.

  • Roger Cicala


    Canon is still selling parts freely and supporting 3rd party repair facilities. As to repair prices, your guess is as good as mine. But I sure do appreciate them taking the time to make it accessible.

  • Really enjoyed the article. Good stuff.

  • Tyler

    @Mike: Did you notice that he has 79 MORE 5DMKIIIs? I think they can swing not having one if it breaks. So his risk isn’t near as high as anyone else, who normally own just one camera.

  • Joe

    Easier repair and maintenance means more money for Canon if it takes less time and effort. I highly doubt Canon will charge less to replace the battery latch on the 5Diii now that it is easier to fix. Does Canon still authorize third-party repair centers, or did they do away with that like Nikon just did?

  • Thanks so much for giving us this tour of goodness. Makes me feel even better about the dollars spent on a camera that performs admirably, but has been criticized for being “overpriced”. I’d love to have spent less, but I don’t think I’ll ever regret the purchase.

  • Rob

    Mike – they are used to repairing equipment, downtime for sending this back to canon would be weeks of lost rental revenue.

  • mike caplan

    I hate to mirror your comments but I shutter to think of the consequences to you had you broken this fine piece of equipment. You exposed yourself to tremendous financial risk. At least your focused efforts to learn more about the camera confirm our lofty expectations of the 1DX.

  • Rob

    Whats your feeling on the weather sealing on the joins and buttons?

  • Chris

    Canon must love it that everyone is negating their warranty on the MKIII.

  • I don’t know if you’re brave or crazy…maybe a little of both?! 😉 Regardless, thanks for sharing pictures. Once you see the pictures with all the “stuff” in there, it helps to justify the price tag just a little bit.

  • Zack

    Did you guys take out the second OLPF while you were in there? Seems to be the thing to do these days haha

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