Error 99 Problem

[DaveBinks]

I have an eos 350D and am experiencing difficulties with a Sigma 70-210 zoom that I purchased some time ago with an eos 100. I first noticed the occasional error 99 when I first bought the 350D, but I have recently upgraded to firmware version 1.0.2 and the first time I took the camera out to use it I have had error 99 messages all the time when shooting in bright sunlight (strangely when shooting indoors I do not seem to get the same error)

[robertwgross]

This question gets asked all the time, and the answer is always the same.

Err 99 means that something happened and cleared so fast that the camera is not sure what caused it. It could be internal faults of the camera. However, one of the most common areas is the lens and the interface between the lens and the camera.

If your non-Canon lens is a little on the old side, then there might be a compatibility problem in the lens. In some cases, the vendor can repair/upgrade the lens firmware to attain complete compatibility. In other cases, the vendor can't or won't do this.

If the lens is fundamentally sound, then you have to look at the interface in the lens mount. There are little gold contacts on the lens side, and there are little gold contacts on the camera side. If the data can pass through there OK, then that is normal. If the pins do not line up right, or if there is the least little bit of dirt or sweat on the gold, then it may work unreliably, and if the camera detects something fishy, it posts Err 99.

---Bob Gross---

[DaveBinks]

Thanks for that, Bob, everything looks pretty good on the lens - I am trying to contact Sigma (UK) to see if they can do anything to help.

Dave Binks

[robertwgross]

I could be mistaken on this, but I think the aperture of the non-Canon lens that was to be used makes a difference, and that might explain why it works good one place and not good the other place. If that is correct, then that would better support the theory that the cause is the lens firmware and not the camera.

When you are pushing the shutter button, a very quick dialog happens between the camera and the lens. Normally, the camera reads the lens capabilities, then meters the scene and decides the exposure settings. It sends a message to the lens sort of like "Set aperture to be f/4."

Then, normally, the lens responds with a message to the effect of "OK." Then the camera takes the shot.

If the camera sends the "Set aperture" message and the lens responds with something unexpected, like "Huh?" The camera will then post the Err 99 warning.

---Bob Gross---

[DaveBinks]

I have discussed the problem with Sigma (UK) and their response was that the lens is of such an age that spares etc. are no longer available and consequently no modification is possible (rather a pity really as the lens worked quite well with my eos 100) - however, I have managed to pick up a better lens (Canon EF 75-300) through ebay - and this one produces great results!

-DaveBinks-

[xuxu1]

I have been asked by other photographers quite often "why i don´t have / use any 3rd party lenses".

Even though there are many (very) good 3rd party lenses on the market, i prefer to stick to Canon,

Exactly... never had an Err 99 problem with my lenses :D and hopefully won´t have any with future Canon bodys.

ED