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
  • Mark

    I got the Error99 as well about a week or so ago, and my camera just keeps snapping away uncontrollably, i take the battery out and it stops..but once i pop it in it starts snapping away again without stopping 🙁 I cant make it stop!!!

  • Travis

    Thanks, Roger. Do you know if the date-time battery is internal on the Rebel XS? I don’t see where it would be accessible without taking the camera apart.

  • Roger Cicala

    That one sounds like there’s a circuitry problem in the camera. Assuming you’ve tried a different battery and replaced the date-time battery, I don’t think there’s anything else left but a trip to Canon.

  • Travis

    Thanks for the awesome article, Roger!

    The issue that I am having with my Rebel XS is that I get the “Error 99” every time the camera goes from being off to on. I have to take one picture, get the error, and then reset the battery. After resetting the battery, the camera will work fine. However, this is the process I must go through after every shutdown, either manual or automatic. Not exactly ideal if you’re trying to take a quick shot. I know I can turn off the automatic shut-off as a temporary work-around, but I’m looking for a more permanent solution. Any advice would be wonderful. Thank you again!

  • Brian Lynch

    Your article just saved me binning a perfectly good camera with both its lenses – the standard EFS and a sigma zoom -but a bad 4gb compact flash card (£12 worth). I feel a bit daft for nearly doing that. Many thanks.

  • Roger Cicala

    Abbudi, did you use the pencil eraser on the camera’s contacts too? There could have been some oil transferred from the lens to them. Otherwise I’d ask what your friend’s lens was. If it was a high current draw lens like a 17-55 IS or 70-200 IS it might have been the last straw in frying a bit of circuitry. That doesn’t seem likely but it’s the only other thing I can think of.

  • Abbudi

    Sorry, not CG but CF Card 🙂 (bad keyboard)

  • Abbudi

    Hello Good people, i got a 30D and i started getting this Err99 after my friend took the camera and tried some other lens and the Error continued even after putting back the stock EFS 18-55 back on!
    i have tried the following:
    took out the battery , the lens and the 1GB CG card ..cleaned the electrik sensors on the camera and the lens with a pencil eraser and after few minutes:
    _ I put the battery on and tried to shoot -No Error
    _ Added the CF card and tried to shoot -No Error
    _ Added the Lens and tried to shoot – Err 99 !!!!

    So what happened here? what happened to the camera after trying that other lens?

  • Niamh

    BRILLIANT! A year of frustration with intermittent and then constant err99 fixed in 30 seconds with a pencil eraser. Thank you!

  • I did the read and it was long however it was worth it. Thanks for taking the time to do the research and helping out the rest of us. Now i dont have to go out and buy a new camera

  • Carlos

    Roger, and all who have commented, thank you for taking the time to help sort Err 99.
    Err 99 for me started sporadically, here and there, then all the time. I searched and found you without to much trouble.
    I have a Canon EOS 400D with an Ultrasonic EFS 17-85mm Lense. I have just the one Lense.
    I opted for this one, more expensive Lense, as it was explaind as being far better than the 2 Lense deals at the time.
    After going through your procedure, it seemed to point to a problem in the Lense.

    After completing the test with no lense and finding no Error 99 i put on the Lense.
    I was indoors, the testing started bad with Err 99 coming up once lense was on.
    I repeated the procedure a second time and the camera with lense fitted then worked inside, all seemed to be fixed?
    At first it worked but as i tried differant settings outdoors the Err99 came up again. Mark above sugested similar. It seemed setting related when outdoors. I put the Camera in its bag.
    The next day i tried the Camera again, Err 99 indoors and out but not on every shot?

    I am going to take the Camera and Lense to a local shop. I will be equipped with this info, if they try and stiff me I will be ready. They charge $25 to look at it and test it? Then if they cant fix it they send it to Canon who charge $80 to have a look.
    I wont stop asking Canon until they tell me what exactley was wrong once it is fixed!
    As a matter of fact they wont get it unless they tell all!
    Stay tuned as i will post it here.

  • Ryan

    Great article! Ok, I have 2 lenses (Canon 28-105mm 3.5-4.5f USM and a Tamron 70-300mm 4-5.6f). The Canon lens NEVER throws and error and NEVER has problems….

    The Tamron on the other hand Err 99s my Rebel XT every time I zoom past 180mm (basically I have a 70-180mm lens.) But it is a bit more complex than just that. I played with the settings in Manual mode and found some interesting things… A bit much to type here but in a nutshell, the trouble zone is the “Macro” region 180-300mm (designated with a gold band on the zoom markers on the lens… you cant go into macro unless your in this range…) Well I was able to get photos to work in that range ONLY if my shutter speed was less than 400… anything 400 or higher Err 99 my camera… I cant figure this out because it seems like some things you mentioned here but also doesnt….

  • Roger Cicala

    Mark it’s almost certainly a lens problem. We see that exact thing every so often. Usually it means there’s a ribbon cable in the lens that’s cracked or loose. At certain positions the cable shorts out causing the problem, at others it passes enough current.

  • Mark

    Hmm more testing. I switched off AF and was able to take manually focussed shots on Auto at greater than 50mm. I’m guessing such a specific issue would suggest a lens problem? Thoughts?

  • Mark

    Jack, the same is happening with my 400D. Only getting the error in daylight. Roger, I am not sure the shutter is the issue. I have dialed down the shutter speed and still get the problem, whereas a higher shutter speed inside with the flash is fine. As it is, I cannot take any outdoor shots. And this is after going through the entire process listed above. Seems strange that the error has never occurred before today, and now effects every shot I try to take. Based on this, logic would suggest its not the battery, contacts, shutter. Just did some more testing and it seems to work fine outdoors on A-Dep, M, Portrait, Close-up and Sports, but not on Auto, Landscape, P, Tv and Av. Am I missing something? What could be a common denominator on these settings? Can anyone suggest any more tests that could narrow down the problem? Would appreciate any help !!

  • Chris Cooke

    Firstly let me say that I have never had any Error codes on any of my 6 Canon Cameras but enough of my friends have for me to read and save your essay and pass it on to my more unlucky friends.

    Let me take this opportunity to thank you for the effort and time you have so generously given to addressing this vexed problem and gratis at that, it is folk like yourself who deserve more plaudits than I am sure you receive.

    Thank you Sir.


  • Nellie

    Oh my God, this totally fixed my camera! I’ve been so frustrated about this, and finally I found an answer. Thank you!

  • Charles

    Thank you Roger Cicala.

    I did make an typing eorror on my sentence:

    “Error 99 message wouldn’t be given when I use my same zoom lens 17-85mm on other Canon digital canmera body as EOS Rebel XTi.”

    Please give me more idea.

    Thanks again

  • Roger Cicala

    Charles, it sounds like there’s a short in one of the ribbon cables in your lens. At certain focal lengths the cable is losing connection and giving ERR99, at other focal lengths it’s doing fine. Sounds like a trip to Canon is in order.


  • Charles

    Error 99 is always appear when I am shooting used my Canon EOS400D with 17-85 zoom lens in the range from 17mm to about 30mm. But error 99 never appears when my lens used in range from 35mm-85mm.
    Error 99 message would be given when I use my same zoom lens 17-85mm on other Canon digital canmera body as EOS Rebel XTi.
    I did clean both contact points, Lens and Canmera body, but it didn’t work.
    Please give me more idea to solve this problem.

  • Roger Cicala


    I expect your shutter is starting to fail: in bright sunlight when shutter speeds are high it can’t cope and is giving ERR 99.

  • jack

    My 30D started giving me this error99.
    I have a EFS 17-85 IS lens.
    one thing I noticed was that the error only comes when it is bright out.
    In trying to shot a sunset it constantly gave the error. But as soon as the sun slipped behind clouds and the dimmer light dominated, I could shot away to my hearts content. Then when the bright sunset returned from the clouds….error99.
    Any ideas beyond what is written in your article? I tried different batteries and CF cards but no change.

  • randy

    i have been getting the error 99 for about a year now. called canon tech and after taken me some steps with my Rebel, he said that to send it in would cost more to repair than the camera was worth,BUT, they were having a special on other Canon camera’s, and i could use mine as a trade in and they would give me about 100 trade in value. i hung up on him.
    i tried the pencil eraser idea and that didn’t work. i think i’ll try buying a new battery(don’t have a backup), try that. and if that doesn’t work, keep looking for more ideas.


    Hello I just had this problem today for the first time. Canon Rebel XSi 4 years old, ScanDisk HC2 16GB card, original Canon Battery, 1995 Canon EF75-300 IS lens with IS on, shutting the camera off and on numorus times did not help, took out and put back in the battery (per the error code instructions) did not help, put in my aftermarket backup battery seemed to correct the problem, even though both batteries showed to be fully charged. just thought I’d add my 2 cents.

  • A very useful and informative article. Found this from a referral on Facebook, and will be making sure that all my other Canon using photo friends out there know about.

    Thanks, and best regards,


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  • Emmanuel

    The auto focus pin is depressed in my camera, its stuck down. due to a 50mm lens that was stuck and was forced out. so far i was only able to take out the two screws in that area and i’m having a hard time taking out the 4 silver screws in the silver ring above it. i only have a small phillips screwdriver with thin metal grip. Is this a fix i can do at home? what should i do

  • In the process of doing your tips right now. But everything makes perfect sense the way you put it.

  • Roy Bailey

    Thankyou I found this very helpful. Manual clean of sensor fixed error 99 on 1d3. Dont think I would have tried that and would have gone through the process of return to service centre. Now a happy photographer again.

  • josephdietrich

    I, for one, found it to be a very useful essay indeed. You basically fixed my camera. Thanks!

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