I have a Canon 400d which works fine with Canon 18-55 lens, but with Sigma 28-200 I get error code 99 and told to switch off and on. this only repeats fault. Any advice would be welcome

zdenek vajdak

• 206 Answers
• Posted on Sep 10, 2007

SOURCE: Canon error code 99

Your camera performs a quick 'integrity' check before each shot and goes into error 99 mode if the lens in incompatible or has a diaphragm problem. ( it will also display e99 if the shutter or flash unit is not ok but this does not apply here ). This is how you can check whether the diaphragm mechanism is ok : attach lens to your old camera and set camera to AV and set F stop to 16 . open back and release shutter and look through the back to see if your lens is closing to F 16. If it is closing fine then the lens is ok but is not compatible with your D400.

SOURCE: Canon 400D error code 01

reset camera by removing battery completely for about 10 seconds.
otherwise, time for service.
sounds like a processor board issue.
you can use a contact cleaner sparingly, available from frys electronics or any other electronic reseller like radio shack.
good luck
mark

SOURCE: i have error 99 in my camera canon 400d

Had this problem before found this guide online


1. Turn off the camera.
2. Remove the lens, battery, and CF card.
3. Allow the camera to sit without power for approximately 20 minutes.
4. Insert a fully charged battery, and turn on the camera.
5. Depress the shutter button as you would to take a picture.
Does the “ERR 99′ message appear? If it does, then the camera should be
serviced. If it does not, then please proceed to the next set of steps:
1. Turn off the camera.
2. Insert the CF card.
3. Turn on the camera.
4. Format the CF card in the camera.
5. Depress the shutter button as you would to take a picture.
Does the “ERR 99′ message appear? If so, then the CF card is the most
likely source of the issue. Try using a different card.
If the message does not appear, please complete the following steps:
1. Turn off the camera.
2. Clean the lens contacts by gently rubbing them with a pencil eraser
or soft cloth. Be careful that you do not let any debris fall into the
camera body.
3. Reattach your lens.
4. Turn on the camera.
5. Depress the shutter button as you would to take a picture.
If the “ERR 99′ message only appears when one particular lens is
attached, then that lens should be examined by a service technician.
If you see the “ERR 99′ with a different Canon lens attached, then the
camera should be serviced.

SOURCE: Error 99 on 30D Canon

Had this problem before and i found this guide online

1. Turn off the camera.
2. Remove the lens, battery, and CF card.
3. Allow the camera to sit without power for approximately 20 minutes.
4. Insert a fully charged battery, and turn on the camera.
5. Depress the shutter button as you would to take a picture.
Does the “ERR 99′ message appear? If it does, then the camera should be
serviced. If it does not, then please proceed to the next set of steps:
1. Turn off the camera.
2. Insert the CF card.
3. Turn on the camera.
4. Format the CF card in the camera.
5. Depress the shutter button as you would to take a picture.
Does the “ERR 99′ message appear? If so, then the CF card is the most
likely source of the issue. Try using a different card.
If the message does not appear, please complete the following steps:
1. Turn off the camera.
2. Clean the lens contacts by gently rubbing them with a pencil eraser
or soft cloth. Be careful that you do not let any debris fall into the
camera body.
3. Reattach your lens.
4. Turn on the camera.
5. Depress the shutter button as you would to take a picture.
If the “ERR 99′ message only appears when one particular lens is
attached, then that lens should be examined by a service technician.
If you see the “ERR 99′ with a different Canon lens attached, then the
camera should be serviced.

SOURCE: Canon error codes

I have a XTi and a Quantaray 70-300mm 1:4-5.6 macro that put up the same error 99.
By mounting the lens with a small piece of thin plastic garbage bag masking the electronic contacts you will find the lens can be used manually. Pictures can be taken continuously with out dismounting lens. I can't set aperture. (F00) ie no lens but can do other stuff .