Hey all,

A bit of a strange question but maybe someone may know of an answer or solution. About a month or so ago I bought a Sigma 170-500mm for aviation photography however whenever I use it on my Canon 7D MK1 it throws up the ERROR 01 code if used between the 170-350mm focal length, if used between 350-500mm the lens works absolutely fine.

To top it off I have used the Sigma on another DSLR body (Canon 1300D) and all focal lengths actually work fine on there. Also no other lenses used on my 7D have ever or currently have this same error/issue

Any ideas or suggestions to what the cause is before I bring it to a camera repair shop would be greatly appreciated,

Cheers and Kindest Regards,

Jordan W