08-26-2023 01:07 PM - last edited on 08-29-2023 11:26 AM by Danny
I'm using a Canon EF-S 18-55mm Ultrasonic lens on a Canon EOS Digital Rebel XT body. The lens works fine from around 30mm to 55mm. I try to take a picture from around 26mm to 18mm the camera does not take a picture and I get an Err 99 message with the lens in ether auto focus or manual focus. Does any have an idea how I fix this problem?
08-26-2023 01:27 PM
Sounds like a bad lens, to me.
08-26-2023 01:29 PM
Not what I wanted to hear, but thanks for the response.
08-26-2023 02:05 PM
Sorry, for the bad news. It sounds like a loose or bad cable inside the lens.
If I remember correctly, as you adjust the zoom from max to minimum the lens gets shorter. But somewhere around 24mm it begins getting longer again, which coincides with how you are reporting the issue.
08-26-2023 02:41 PM
That is exactly right. My brother gave a replacement lens. Perhaps I can scavenge a part off of it.
I would just use his but it's not an ultrasonic lens.
08-26-2023 03:55 PM
The replacement lens more than likely uses an older AF motor called Micro Motor. Your lens has what is called Micro Motor USM. It's not the high end Ring Type USM. That supports very fast AF. Canon has made 3 different types of USM AF Motor lenses.
08-26-2023 03:25 PM - edited 08-26-2023 03:25 PM
See this topic on a similar problem:
https://community.usa.canon.com/t5/EF-RF-Lenses/Autofocus-not-working-18-55mm-lens/td-p/138114
08-26-2023 03:40 PM
Actually the OP has the Micro Motor USM version of the 18-55mm kit lens. These lenses were mainly sold in Asia. So this won't fix the problem. Also Micro Motor USM lenses DO NOT support manual focus override. Except for the EF 50mm F/1.4 USM lens. That lens has an additional clutch system to allow manual focus override. Like a Ring Type USM lens with a mechanical focus ring.
08-29-2023 11:19 AM
"I would just use his but it's not an ultrasonic lens."
Any EF-S lens will work on your camera.
Your XT is approaching 20 years of age. Not that it is bad but it is something to keep in mind. I still have cameras that are even older.
12/05/2024: New firmware updates are available.
EOS R5 Mark II - Version 1.0.2
09/26/2024: New firmware updates are available.
EOS R6 Mark II - Version 1.5.0
07/01/2024: New firmware updates are available.
04/16/2024: New firmware updates are available.
RF100-300mm F2.8 L IS USM - Version 1.0.6
RF400mm F2.8 L IS USM - Version 1.0.6
RF600mm F4 L IS USM - Version 1.0.6
RF800mm F5.6 L IS USM - Version 1.0.4
RF1200mm F8 L IS USM - Version 1.0.4
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