lens probems

[dulceza]

I am on a trip right now and I noticed that the lens doesn't find the focus, hunting backwards and forwards. Any suggestions much appreciated.
Dora

[Manfred M]

Hi Dora - do you have any details? Camera body and lens info would be a good start. Type of scene you are trying to shoot when this occurs, lighting conditions, etc. Not much to go on otherwise....

As an example, this is something I get with my 80-400mm lens when shooting at the long end, especially when shooting flying birds

[Geoff F]

WE really need a bit more information on your equipment.

Are you on AI Servo, or equivalent. Are the lens to camera electrical contacts clean. What sort of subjects are you shooting?

[rpcrowe]

This happpened to me early in my use of the 70-200mm f/4L IS lens. But, I don't know if this is your problem... I had the focus limiter switch set to 3m and I was between the closest focus point of 1.2m and the 3m. Switching the limiter to 1.2m and or backing up for a longer lens to subject distance solved the problem.

Aditionally, sometimes when there is nothing contrasty to focus on (such as shooting a gray wall) the lens will hunt.

Finally, there are some lenses which do not have great autofocus capability. As an example, the "Nifty-Fifty" 50mm f/1.8 will sometimes hunt in lower light levels. My old Tokina 400mm f/5.6 ATX was also guilty of hunting...

[dulceza]

Oh, my camera is a Canon T2i and I have probems when using manual mode, both lenses-18-55 kit lens and 70-200 mm. The sun is very bright indeed and temperture is often around 35C, but I don't think that's a problem. I am not in AI Servo
Thank you

[abhi]

Oh, my camera is a Canon T2i and I have probems when using manual mode, both lenses-18-55 kit lens and 70-200 mm. The sun is very bright indeed and temperture is often around 35C, but I don't think that's a problem. I am not in AI Servo
Thank you

Hi Dora,

Are you having problems with both lenses? If you are manually selecting the AF point, you could try changing it to see if that helps. I had a similar problem with my Rebel. Turned out that one of the AF points had stopped working.

[dulceza]

Hi Abhi, I am not selecting manually the AF point , I had just one of the 9 AF points working, manually I can't get none of them working. What did you do to fix the probem?
thank you,

[abhi]

Dora,

Only one AF point had stopped working in my case. So, I had just stopped using that one. But, I would think it to be highly unlikely that all stop functioning together. Sorry can't be of much help with this.

Is it possible for you to call any Canon service center? They might be able to help you do some basic diagnostics to narrow down the problem over phone.

[dulceza]

Hi Abhi,
Yesterday I didn't understand your explanation (it took me a while to figure out ), but today I manually changed the AF point and it helped. Thanks again

[abhi]

Hi Abhi,
Yesterday I didn't understand your explanation (it took me a while to figure out ), but today I manually changed the AF point and it helped. Thanks again

Glad that you can use your camera again, Dora. Looking forward to the photographs from your trip.