Is there a problem with the lens mount?

by planetmitch33 Comments

Ok, I've ignored this issue for a few days wondering if it was really really isolated, and after a few days, more than a couple have reported this, so in order to investigate the issue, I'm reporting it. I don't think it is something to start a panic over, but it seems that it should at least be exposed to a wide audience to see if there are hidden cases that aren't being reported.

Have a tip, a video, or a Canon 5D2 product to announce? Give us a shout

Several days ago, posts on twitter and a post on the Photography Show blog (by Gavin Seim) appeared asking if anyone had an incident where their lens had fallen off of a Canon 5D mk ii. Here's a quote from the blog:

“Those who listen to the PPS podcast are aware that I recently sent my brand new 24-70 2.8 L lens to Canon for repair because it fell off my 5D MK2. I love my MK2, but I was on the dance floor at a wedding happily shooting away and next thing I know my twelve hundred dollar lens is rolling on the floor. Pretty disconcerting.

There’s was that chilling intake of breath from the crowd, that most of us who have publicly dropped a piece of gear are all to familiar with. Like any pro, I kicked the lens off the dance floor with disdain, while casually saying. “Heck that old thing. I have a whole case of them in the car”. OK seriously though, I kept cool and finished the wedding just fine. If you want to hear about that listen to PPS podcast #58.

Naturally Canon treated the situation as if I’d dropped the lens outright and the the repair cost me about $200. Not a huge deal. I figured perhaps I somehow hit the release button. Then I got to thinking. Should that happen since you we you have to to rotate a lens with some pressure to take it off. Probably most people thought I was being clumsy and did something wrong. I was using the camera quite normally however.

I was about to let it go when I found I’m not the only one this is happening to. Seems that there’s various reports coming in about lenses falling off the MK2. More all the time. So I decided to write this post to talk about this. Does this happen commonly? How about on other cameras besides the MK2. Do Nikon’s ever have this issue?”

It is a legit concern if people are having a problem and so I'm trying to spread the question. I don't agree with the tone of some of the replies in that blog (read the comments)… some are making it sound like a huge issue and that everyone is having a problem.


The lens mount is a twist mechanism with a lock at the end of the twist. Obviously Canon has been making these for maybe a decade and I can't imagine how there'd be a flaw in the 5D mk ii, but it is possible. After reading some of the posts, I spent a few minutes trying to abuse my 24-105 on my 5D mk ii and I couldn't even force it to come loose with some vigorous shaking. Even pushing in the lens release button and letting it go (without twisting the lens to begin to remove it) would not make the lens come loose. But maybe that does happen in the case of these other users? Has it happened on other Canon bodies?

Sound off over in Gavin's thread (best to keep everything together).


  1. “Even pushing in the lens release button and letting it go (without twisting the lens to begin to remove it) would make the lens come loose.”

    Did you mean ‘wouldn’t’?

  2. That is quite worrying. I have to say though that in using my 5d2 it feels extremely. I’ve been in the middle of protests getting pushed around and falling over a few times and so far so good *touch wood*.

  3. Author

    @kj… well, I don’t think that I’d say it is “quite worrying” yet – there have been maybe fewer than 10 reports that I’ve seen (and all of them on that one post)… it sure doesn’t seem widespread, but that’s what I’m hoping to find out.

  4. I’ve had a lens fall off a Canon (not a 5D though). It is very unlikely to be a fault in the mechanics. The most likely explanation is as follows:

    1) You catch the release button while shooting and knock the lens slightly.
    2) All is fine, but the release button is now locked in.
    3) You carry on shooting, not realising anything is wrong.
    4) You rotate the lens to zoom or focus.
    5) Kapow… Lens on floor. Daft looking photographer.

    I love that the Canon lens mechanism makes it easy to change lenses. However it make be a little too easy. Time for a locking latch perhaps?

  5. Pingback: Is there a problem with the lens mount? - planetMitch (planet5d) | Photo News Today

  6. And, of course, the main reason lenses are dropping off the 5DMII is that users are unseating them to shoot video!!

    It’s not a surprise that those reports are popping up. Remember, everybody’s innocent!

    1. Author

      You could be right – at one point, I was going to mention that in my post, but I guess I got distracted… thanks for posting it!

  7. I wonder if these people were using manual focus. I can see how, if there is a problem with the lens latch, and they are twisting away at the focus ring, they could unscrew the lens. Seems if you were using AF, you’d notice it stop working as the contacts seperated between the body and the lens.

  8. You know, you’re right. One of the differences between the 5DMK and all the other Canon DSLR’s that I have owned is the video. I have never taken the lens off to ‘trick’ the aperture but I do use manual focus while shooting video (forced to really). So, yes, if the button gets pushed and stays ‘locked’ for lack of a better word in that position – then I start using manual focus while in Live View this could easily account for the lens being twisted to the position where it could become loose.

  9. Lenses have been stable, but I have had several camera freezes. Power to the screen, but nothing works. The only cure is to take out the battery and re-insert it, and the camera returns to normal operation. It hppens occasionally, for me 3 times, but I can’t recollect the sequence that creates the lock up. I’ll try to recollect and recreate the next tme it happens.

  10. I’m kinda shocked that everybody is taking sides with Canon on this. I was using AF and no video, but are you actually serious? It’s OK that lenses fall off because people might have been using MF. Last time I checked MF was a normal feature of the camera.

    People laugh like the people who deal with this are just making excuses because they messed up. I wounder how long that will last if expensive lenses start falling of your camera.

    I love my canon Cameras, but I have to say the fanboy’ism is a bit crazy. I’ve not heard ONE report of a lens falling of a Nikon.

    Truth be told I don’t care what the useage situation was. If any lens simply falles off unexpeted then we have a problem.

    1. Author

      Gavin – thanks for chiming in… but I don’t see ‘everybody taking sides with Canon on this’ – there are comments on all sides both here and on your blog. I think there’s reason to be concerned, that’s why this is here… but at the same time, we don’t want to raise a panic (which can happen easily on the ‘net).

  11. Yeah Gavon, no fanboy comments here. I even said “if there was a problem with the lens latch”.

  12. I’m inclined to side with Canon as well, because I’ve owned 35mm SLRs for almost 40 years (Nikon, then Olympus, now Canon), and have never had a lens fall off.

    As with most mounts, Canon’s has three “mechanisms” to keep the lens in place. The first is the bayonet itself. The second is springs within the camera that press against he bayonet’s flanges. The third is the locking pin. Even with just the springs holding the lens, it’s essentially impossible for the lens to come off without being intentionally removed. There’s too much resistance.

    I checked, and discovered that, on Av, you can take correctly exposed photos, even when you haven’t turned the lens far enough engage the springs (let alone the locking pin). (Autofocus doesn’t work, though.)


    I suspect Gavin was in a rush, and turned the lens only halfway when he mounted it, without noticing that the bayonet hadn’t made contact with the springs. The lens gradually slipped around (was Gavin dancing?) and fell off.

    “When you have eliminated the impossible, whatever remains, however unlikely, must be the truth.” — Sherlock Holmes

    PS: Canon does have a locking latch — you just have to turn the lens all the way. I preferred the Olympus latching system, as each lens had its own release button. This made it easier to remove the lens without having to fiddle with a button on the body.

  13. Ok well we’ll have to see I guess. I will do some more experimenting. If it was only me I’d say yes, but there are various ppeople on the PPS blog post and twitter who have had a simlar problem. Can’t be considence.

    @William Sommerwerck “As with most mounts, Canon’s has three “mechanisms” to keep the lens in place. The first is the bayonet itself. The second is springs within the camera that press against he bayonet’s flanges. The third is the locking pin. Even with just the springs holding the lens, it’s essentially impossible for the lens to come off without being intentionally removed. There’s too much resistance.”

    It did, what can I say. I didn’t make it up to get free lens repair. I already had to pay up for that.

    Correct me if I’m wrong bit doesn’t the lens have to lock in for communications to work. When this happened I was actively shooting a reception and using AF. I need to do some experimentation but the lens should have to be locked before AF works.


  14. This has happened twice to me. I think the button is to big, and easy to hit when you grab the camera from the bag. Then the lens fall of when you take it up from the bag. Once my brand new lens dived into the snow and got lost for a while. Not nice. I think Canon should make a smaller button, and a button who needs more pressure to release it. Now it´s the biggest button on the camera!!!

  15. If by “locking”, you mean the pin popping into place, no. All that’s required is that the lens be turned far enough that the contacts on the lens align with those in the body. And that occurs slightly before the lock position.

    I checked to confirm this. You can move the lens ever-so-slightly from the locked position, and it will still auto-focus. If you then try to zoom, and keep turning the zoom ring without paying attention — yes, you could turn the lens far enough for it reach the $200 repair position.

    The only other likely explanation is that some cameras have broken latching mechanisms. Even then…

  16. Ray, You’re the first person I’ve seen mention 5D2 lockups. I’m getting them very frequently as well. I can’t seem to isolate the cause to a specific lens or shooting situation, but yesterday it happened when I quickly fired off several shots in a row (in single shooting drive mode).

    The symptoms are that none of the buttons except the shutter release works, the screen will not light except to show sensor cleaning when the camera is turned off, but the dials continue to work normally. Removing the battery sometimes clears it, but sometimes I just have to let the camera sit for a while to recover on its own.

    Has anyone else seen anything like this?

  17. Perhaps I shouldn’t stick my nose into Roger Goun’s question — but I will, anyhow.

    The fact that removing the battery or letting the camera sit for a while fixes the problem suggests that the cause is electrical (rather than a software quirk). I’ve seen similar problems in LD and DVD players, PDAs, and even TV sets. The unit “misbehaves”, or even stops working altogether, until it’s had a “time-out” to recover (which can be several days). I call it “CMOS lockup”, but whether that’s the cause, I don’t know.

    Do you or Ray work in an unusually dry environment, or one in which you experience static discharges when touching doorknobs, etc?

  18. I haven`t any this problem on my 5D MKii, I would also suspect the photographer had accidentially hit the release button, without him noticing..
    I also gave it a shot to see if I could release the lens mount accidentially, but to no avail… could be as mentioned before, that the locking mechanism could be faulty / not locking properly on these cameras… who knows.. one things for sure, I dont have this problem.

  19. !!!!!!week ago i had the same problem.. but not in action, just walking around.. !!!

    having the camera ^mounted with my 70-200 2.8 is L around my shoulder , it dropped itself while walking!!!

    damn.. searched the forums for problems i though i gonna crazy.. other people had the same problem.

    so whats the matter with it

  20. I have tried this with my 24-70 2.8L on a 20D, 5D and 5D MkII and cannot replicate the problem when the lens in installed on the camera and the Locking Pin is engaged.

    If however the Release button on the Camera is depresses and the lens is ever so slightly rotated in a Counter Clockwise direction on the mount, the Locking Pin on the lens release will remain disengaged. (It has to in order for you to be able to remove the lense).
    Under these conditions it will be possible for a lense to rotate to a point where it could drop off.
    The 24 -70 lense has to rotate through approximately 60 to 70 degrees before the lense is able to part with the camera body. This is due to the design of the Bayonet and Flange design on the Body and lens.

    I would say it is possible for a lens to drop off but you would have to inadvertantyly unlatch and rotate the lense close to a full quarter rotation for this to happen.

  21. I’ve more Canon bodies than I can count and I have this precise problem with the 5Dmk2 only. In my case I found it whilst carrying the body/grip on my 300 f/2.8. I put it back on, carefully checking that I have not suddenly forgot to do what I’ve done for a very long time. 5 minutes later, the body drops off again, this whilst carrying the lens/ body on the lens strap over my shoulder

    It’s a problem with my 5D2. Sounds like you have the same one.

    There is no possibility that I could be pressing the lens release button (what are these guys on suggesting such a thing?!) – the camera’s hanging from Canon’s strap on my sounder.

    I can’t make it happen manually, and it did not happen for the first n months I had the camera. It happens very easily now, so I will have to get it repaired.

  22. 100/400L Lens fell off my 5Dmk2 3 times in 1 day not using video not using manual focus hanging from shoulder strap and walking. Carefully refitted lense after first incident . Tied the lense with a cord after 2nd event.
    Lense was knackered and I had to have it repaired. Camera is nearly 2 years old and it never happened to me before.
    Really not happy with the equipment What if you’re shooting off a bridge or something and the lens falls off and hits someone below or just gets ruined etc.

  23. Just had this happen to me today. 24-70mm L series inexplicably fell off my 5Dmark II while I was setting up a shot. It had been mounted to a tripod.

    This is the 2nd time this has happened with a different 24-70 lens, same camera body.

    Lens seems to be ok, but it is extremely tight putting on and taking off and the zoom mech is sticky. What gives Canon?

  24. Same thing happened to me with my 70 – 200 2.8 and my 24-105 4. I thought I was an idiot when it happened to my 70 – 200 but when it happened about 4 weeks later with my 24-105 I took the 5DMK II back to my dealer. They sent body and lenses off to Canon and it has been a nightmare since. Fighting with Canon Canada for 5 weeks now and still no resolution. They will test and adjust the Camera for free (Warranty) but will not cover lens damage. My contention is if the camera worked properly the lenses would not be damaged. Anyone have any suggestion how to convince Canon Canada that the issue lies with a defective camera lens mount release and not the user? Please help a brother out.

  25. Will, I got stung by this today. Probably the worst scenario you can imagine.

    Shooting a wedding, as the bride started walking down the aisle, my 70-200 detached itself in my hand. In shock, and under pressure, I just put the lens down and swung my second body (with a 35mm) into action. Luckily I nailed plenty of good shots, but it shocked me. Really knocked my confidence (especially as several of the guests noticed).

    The way I see it. Even if I had knocked the release button, the design should be so that this is not sufficient for the lens to detach. I personally think the release button should be in a recess, or even have a design more like a switch.

    Almost ruined my day. Canon should sort this issue – it stinks!


  26. Canon lens

    The reason complainants (myself included) make such a big deal over this is because trashing a new £2000 lens through a faulty design and getting the brush-off from Canon is indeed a big deal!
    I’ve just recieved my new insurance replacement 70-200L f2.8 IS Mkii and I can VERY easily replicate how easy it is for the lens to become unlocked and work loose from the camera body. It’s so ridiculous that I’m going to record a short you tube clip to warn non-believers!
    I’ll post a message here when I’ve done that.
    But just to help in the meantime I can offer a little advice which could save you a lot of money:
    If you use a 70-200… REMOVE THE TRIPOD FOOT when not in use… it makes a very efficient lever!!

  27. My 24-105L just fell off my 5D mkIII and rolled into the Seine. The lens release button is way too sensitive and it is so easy to accidentally unlock without realizing it. I went to twist the zoom ring and the lens rotated and dropped off. Blogs are full of compaints of this occurance on mkii’s.
    This is definitely a design flaw. It’s not user error. The button should be relocated or made to require more force to release or have a detent position.
    It’s a shame that you have to gaffer tape a $2300 lens to a $2000 camera. Be forewarned.

  28. The same thing has happened to me a few times while zooming out with both lens. I came to research why this is happening, after reading how the fortunate ones blame the unfortunate for releasing the lens, I experimented and I have come to discover that my locking pin does not lock at all. In my case the camera body is the problem. Canon 70d, EF-S 55-250mm IS STM, EF-S 18-135mm IS STM.

  29. Further experiments demonstrate the problem is indeed the camera body. The issue is in the spring-loaded locking pin. The spring under the pin seems to have worn-out and is no longer pushing the pin up to lock the lens. The pin seems to be stuck, it comes out of its cylinder slowly (eventually). It appears as if stuck within some sticky/gooey substance, so while mounting the lens I can hear a click indicating the lens has reached it locking position. However, the pin never popped up to lock, so the lens fall out When zooming all the way out. For the other folks with a failed locking pin, the lens falling out could be caused by motion and gravity. In most mechanical applications, a cleaning solution/spray would have most likely help resolve the stickiness, however, this a sensitive and expensive piece of equipment. I believe it should be sent out for service. It’s a shame since the camera is probably less than 3 years old and had little use.

    One important note: I found that I could to get the lens to lock by rapidly pecking the lens release button off-center (around the edges) a few times until the pin popped up into locking position.

    Most of you seemed so sure of yourselves while having never experience the problem. This is the internet; the majority seems to always think they are correct even when they are dead wrong. you have pushed me to research and figure it out on my own. And I thank you for that.
    Canon 70D, EF-S 55-250mm IS STM, EF-S 18-135mm IS STM, EF 50mm STM.

  30. I had this happen with my 6D and a 24-70 lens. Almost the same scenario. Taking pictures at a wedding dance when I got bumped from behind by another guest with their cell phone camera. this is where my 24-70 flew to the ground with a bone-chilling crunch.
    Today, I received a call from a professional photographer friend who had his 100mm Macro fall off his 6D as he was bringing it up to take a shot.
    I am beginning to think that there is something going on. I have owned SLR’s by canon since the early 80’s and never had this happen in all my years of experience.

Leave a Comment