How To's

Canon’s Error 99: the Man, the Myth

Published December 31, 2008

This article was updated in April of 2009 after Mark at Precision Camera, our favorite repair shop, provided us with some additional information.

This is probably the most boring article I’ve written for LensRentals. (Personally, I like Smashed Front Element the best.) But, I love a good mystery, and I love debunking dSLR “urban legends”. Every so often I run across an online forum where someone makes broad statements about Error 99 which I know are incorrect or at least incomplete. As is my practice, I’ve boldly charged into these online gunfights devoid of intellectual ammunition (i.e. facts). And predictably, the intellectual level of the discussions quickly spirals down from “Is not”, “Is so” into the traditional online-forum sign-offs of “You get Err99 because you’re a bad photographer” and “if you’ve never gotten Err99 you’re obviously not taking many pictures”.

Because Canon Corporate apparently believes that releasing no information about a problem makes it go away, there is little factual information to debunk the online myths regarding Err99 unless you really do a lot of digging. Googling Err99, Canon EOS error codes, etc. brings up several dozen pages of links most of which are the above mentioned “discussions”. There are a few nuggets of truth out there, though. The most complete of these is a multi-year 2,300 post discussion of Err99 problems at Richard’s Notes. There are also a few thoughtful and factual discussions that have taken place in some of the better forums online. After spending far more hours than I intended looking through these sources to settle an online debate, I thought I’d write a summary of what I found and what we’ve experienced here— LensRentals has over 700 Canon lenses and over 50 Canon bodies (as of December 2008), so we have a bit of Err99 experience.

The Myths

Some of the most common Err99 myths are listed below. Strictly speaking, they are not myths; almost every one is true. The myth part comes from thinking that any one of them is actually the cause of Err99. So:

  • Err99 results from an electronic communication problem between the lens and the camera.
  • Err99 results from using third-party (i.e. Sigma, Tamron, Tokina) lenses.
  • Err99 means that electronic circuitry in the lens has failed.
  • Err99 means that electronic circuitry in the camera has failed.
  • Err99 results from using third party batteries.
  • Err99 is a firmware issue, and can be fixed by upgrading to the latest firmware.
  • Err99 started with Canon XT and 20D cameras.

There are a lot more. Almost all of them are true for at least some cases of Err99. The best myth, though, is that Canon purposely created error 99 to prevent the use of third party lenses. As best I can tell, that one isn’t really true, but it does make fun speculation. And, of course, Canon’s nearly total silence on error 99 and other problems certainly helps feed the conspiracy theorists among us.

Author: Roger Cicala

I’m Roger and I am the founder of 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 How To's
  • Thanks so much for this article. It’s the best info I’ve found.
    I have a 20D and it has just now started giving me the err99. It only does it when I try to take a horizontal photo. I can shoot vertical or with the camera pointing straight up or down and it’s fine, though the vertical is having its problems in colder weather it seems …
    I’m getting through for now by holding my camera upside down for horizontal shots 😛 lol
    It does this with any lens and without the lens. Battery pack or not, cf card or not … I started using 4GB SanDisk cards and I ran my batteries dry in my battery pack the same night I began having this problem. Maybe something to do with that? Or it’s the shutter curtain

  • I’ve had ERR99 on 2 Canon bodies: The Rebel XT (350d) which had been in storage for months…problem was sticking pop-up flash mechanism. A little gentle persuasion fixed that for good.

    The second was a 1dMk3 which had developed an autofocus problem (blurred images). As part of the elimination process, I upgraded firmware from 1.2.5 to 1.3.0 which I hadn’t done previously as the 1.3.0 relates only to the wireless transmitter improvements.
    I got ERR99 on the first exposure immediately after the FW upgrade.
    It went away for a while then came back with a vengeance after the camera came back from repair for the AF issue.
    The 1d3 has just returned from it’s second visit to the Repair Centre for ERR99 with the fix simply listed as ‘Reset’

    The one thing I hadn’t tried was the date/time battery and I can’t help thinking there is some relevance to to it occurring straight after a firmware upgrade?

  • I have a Canon 30d and have gone through your list of potential fixes to the Error 99 issue. None seemed to work so I decided plug the camera into the computer and remotely trigger the camera just to see if my computer would say something about the error. What I found is even though I fully charged the battery (original from when the camera was purchased) and the camera displayed a full charge, the computer software warned me that the battery was depleted and advised me to change batteries. When the message would pop up on my computer, the error 99 would surface again on my 30d.
    Do you think there is a short in the circuitry or I just need to go out and purchase a new battery?

  • Karen

    Have the same set up as Susie above- but a Quantary lens- same issue- works fine with the small lens but not the larger…just changed out battery-nothing,changed card-nothing although it took 1 photo then popped up error22…guess we’ll have to take it in and have it checked out…sigh…

  • Roger Cicala

    Bruce, that’s possible, or maybe the aperture electronics are not quite right and just need more power than your 20D is delivering. Trying another high current draw lens like you mention might clarify it, especially if perhaps the 20D battery isn’t quite up to max voltage.

  • Bruce Johnstone

    Roger, great article covering the issues. I have a 20D that gives the Err99 with a Sigma 135-400 lens. I have found that the camera won’t stop down with the depth of field preview button on that lens only. When the aperture value for an exposure is smaller than wide open I get the Err99 with that lens. I have tried the lens on three different older bodies; D60 and digital rebel and film rebel and it works fine in all modes and stops down with the preview button. The 20D will stop down with all of the other lens I have tried just not the Sigma. Both lens and camera seem fine but just won’t work together. Do you think the Sigma is just trying to draw to much power? I haven’t tried it with an IS lens.

  • Roger Cicala

    It sounds like there’s a problem with the aperture of the Tamron lens: either electrical or possibly something mechanical in the leaves of the aperture. I’d have that checked first.


  • Susie

    I have a Canon Rebel xti and for the last four months have been getting the Err99. It happens when I use my Tamron lens, 75-300mm 1:4-5.6 Tele-Macro, and I try to move my f stop any higher than the lowest it will allow me. For example: I have it set at f4 and want to move it up to f4.5 it will do the error99. I just recently had it cleaned after vacation to the beach and it still happens. It doesn’t do it with my other lens, Tamron 28-80mm 1: 3.5-5.6 . So I’ve tried the eraser, I’ve tried taking the batteries out, lens off and card out and the problem is still happening. Any other suggestions??

  • Roger Cicala


    I believe you are correct. There are several gears that can jam the mirror and a local camera repair shop can probably fix them without a replacement.

  • Ashish

    Excellent article. I tried most of the suggestions here, but couldn’t get the error to go away. The only way my 4 year old 40D works is in the Live View. This seems like an issue with the mirror not coming down in time while taking the picture.

    Can you please provide some guidance in terms of fixing this issue?


  • Lou

    I had gotten an err99 after DROPPING my EOS! Figured I did it in. After reading about lens and contact issues I took of the lens to clean the contacts. It was then that I noticed that the mirror was not straight. When I dropped the camera, the mirror shifted and went out of allignment. I took a plastic fork and gently moved the mirror from the backside. The mirror popped into place and the camera works! I don’t recommend this, but it worked for me. Just another err99 code fix!

  • Roger Cicala

    I’ve seen that happen several times: a higher current lens like the 17-55 f2.8 IS or 70-200 f2.8 IS is put on a camera that’s been fine, ERR99 starts showing up, and doesn’t go away with any of the usual things. The only cause-and-effect thing that makes sense to me is the camera had to supply more current than it was used to with the bigger lens and something that was borderline crossed the border. It could be a cell in the battery went bad (I assume you’ve tried a different battery) but it could also be a bit of circuitry overheated and died. In the latter case a trip to Canon is the only real solution.

  • Lane

    Hi Roger,

    I read Abbudi’s post and also your reply that what possibly could have happened was damaging the circuitry? The lens I tried on my Canon 450D was a 17-55 IS – after shooting with this lens for a maybe a dozen shots, I then received the error 99. I have tried absolutely EVERY possible solution listed in your essay, but my camera still does not work. May you explain a bit further about what could have happened, how I could possibly fix it, or if it’s a lost cause? Thank you!

  • Roger Cicala

    There are no particular issues with the 60D that I’m aware of. One of my favorite cameras (except for not having autofocus adjustment). The 17-85, though is another matter. If you can swing the extra money I really prefer the 15-85 IS. It’s a much better lens.

  • John from PA

    I just acquired a 60D and I note that although this camera is about a year old, I can’t find any Err99 issues reported with this camera. Any particular reason? With respect to the 60D, is there a date-time battery and if so where?

    I also am about to acquire the 17-85mm EF-S lens which does seem to be a bit more prone to the issue. Having said that, I think you hear more about the problems than the good side of things. Should I be concerned about the 17-85mm lens choice

  • Dave Walberg


    Great post, interesting comments. For my situation I have narrowed things down since I have two cameras to test with. With both a Rebel (300) and an XT (350), the problems stays with the 17 – 85 EFS Canon lens. Contact cleaning, battery change, CF card don’t seem to matter. The err99 happens with either camera but NOT when the aperature is wide open. Also, I found that it is related to the 17 – 24mm range. Since I’m also having a problem with autofocus, I guess it is time for a repair (after about 40,000 photos).

    Thanks for your rather throrough discussion. Too bad Canon won’t address the issue as much as you have.


  • AndyO

    Excellent article. Just a shame it isn’t Googles top ranked result!!

    To add my dire experience to the list. I just sold a 30D which the buyer reported the issue on (news to me) and have had to go thru the whole Ebay refund experience. The error occurs intermittently and less so after battery removal & replacement.

    One factor not mentioned here.. it happens without a lens or card attached so its a fault with neither. The buyer even bought new batteries (and I included 3) so thats out also.

    With lens & card it shoots the image and stores it perfectly well to the card also when the error is displayed (on subsequent viewing).

    So the only real issue is the actual error message appearing at all! You have to wonder if the error reporting could be bypassed whether there would even be a problem?!! Firmware hack anyone?

  • Roger Cicala

    Nige, it could be battery, could also be shutter.

  • Nigel

    I having this issue intermittently with a 1D mkII and with both the canon 15mm fisheye and the 24-105mm f4.0L and only having it come up when shooting sequences on high speed drive mode. This gives me the indication that it is a battery issue. Has anyone else had a similar issue??


  • Roger Cicala

    Dan, I bet one of the ribbon cables or connections in the 17-85 is cracked. At certain lengths the signal is getting messed up. We’ve seen that several times.

  • It seems to be fixed! I stopped using the Japanese lenses and the Canon lens seems to work correctly. No error 99! Thank you so much!

  • Dan

    Here is an interesting twist – Rebel XT with a 17 – 85mm IS Canon lens that I use as my every day lens.

    This only happens when I’m set between 17 and 24mm – once I move it a little past 24mm, I can usually shoot continuous frames with no issues

    When the lens is between 17 and 24mm, I usually get this after 2 or 3 shots, and then every time after I flip the power on and off…

    I have a Canon 70 – 300mm IS that works fine across the focusing spectrum as well as a Tokina 12 – 24mm that works fine… so I’m assuming that it is an issue with the lense

  • Martin

    …and then again perhaps not – I took the camera to the coast today and nothing worked!!

  • Martin

    Hi, Roger. I think you may be right, although I did tonight take some more test shots with the lens’ autofocus switched off and it performed fine. Maybe I’m just going to have to get used to manual focusing, at least with this lens.

  • Roger Cicala

    Martin, I think it probably is the end of the road for this lens: If it can’t be rechipped it’s not going to work with newer SLRs.

  • Martin

    Hi. Just bought an EOS350D body to go with my trusty Sigma 50-200 telephoto zoom, which had always worked perfectly with my previous EOS film camera – an EOS850. I’m getting about 90% err99 and the odd 1% of decent exposures. Had it never worked at all then it would be one thing, but for it to tease me by working occasionally is really frustrating.

    I’ve tride the eraser-on-the-contacts and aso swapping out batteries (I also have the battery pack grip, but the error happens with that attached too).

    I’ve emailed Sigma who told me this lens is not re-chippable; is this the end of the line for this pairing? 🙁

  • Where did all my post go?

  • Will Butler

    Thanks so much, never heard of the aperture issue before, which is certainly what is wrong with my lens. Do i send it off or can i cope with f4-5.6 for the rest of its life!?

  • Forgot to tell…I think it started to give mi these problems after my flesh hot-shoe brake, when was attached to the camera, but I’m not fully shore.

  • Hay
    I own EOS 40D body and now for 14 days it gives me err99 problem. I managed to test a bit when error occurs. It shows same problem like @Travis has. It works after you put battery in , but soon after camera goes to off, or if I put it to OFF and then ON it shows err99. But I saw that if I take out CF card it works normal…even if I turn OFF the camera and turn it back ON. Also in live view it works fine. I tested 3 CF cards which works perfectly in 7D body…and also tried with different batteries. Didn’t change internal battery, I have in plan to change it today.

    What could be the problem?

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