After thorough investigation, we have ascertained that some APO 50-500mm F4.5-6.3 DG OS HSM, APO 120-400mm F4.5-5.6 DG OS HSM and APO 150-500mm F5-6.3 DG OS HSM lenses, produced recently, may have a potential autofocus defect.

This issue could possibly occur in some lenses within the following range of serial numbers:

This is a limited problem that will not occur in any lenses other than those specifically listed above.

To overcome this issue, we will be offering our customers an inspection and where applicable, a modification service, free of charge. In the case of any autofocus problem becoming apparent on inspection, we will rectify the situation and make every effort to minimise delay and inconvenience.

If you are the owner of one of the above three focal lengths but your serial number is different to those specified above, then you need take no further action. If however you are in possession of one of the lenses with a serial number mentioned above, you will only need to contact us if you are experiencing an autofocus problem.

If you are not experiencing a problem, you need take no further action.

If however there is an issue, please contact us on our special helpline 01707 376 795 and we will arrange to collect your lens at no cost to yourself. In the unlikely event that the inspection uncovers a potential problem, your lens will be modified and returned to you absolutely free of charge with the minimum of delay.

We deeply apologise if any inconvenience has been caused to our customers.

For further information, please visit www.sigma-imaging-uk.com/returns , call our helpline on 01707 376 795 or email us at This e-mail address is being protected from spambots. You need JavaScript enabled to view it .