Sy V
Well-known member
Last Saturday I bought a used Sigma 500mm f/4.5 EX APO DG HSM (3rd Owner, originally supplied Oct 2007). Initially I was unable to get a sharp image out of it despite using a Manfrotto tripod and head with an electronic shutter release.
A couple of nights ago I downloaded some focussing charts and it soon became apparent that the lens is back-focussing (by about 5 cms over 10 metres).
Just to confirm this I dialled in some compensation to my Canon EOS 7D and that has improved matters to some extent (unfortunately there's little advice available as to how much or little to compensate).
Not wishing to spend weeks on a trial and error mission I contacted Sigma UK with a view to them recalibrating the lens.
They can be contacted here:
Service Department
Sigma Imaging (UK) Ltd
13 Little Mundells
Welwyn Garden City
Hertfordshire
AL7 1EW
Or, by emailing [email protected] or telephoning 01707 329 999.
They recommend sending the lens to them by courier. They quote between 2 and 3 weeks to turn the job around and a simple adjustment (to address the focussing issue) is £34.73. If they discover other problems they will quote before carrying out the extra work.
I'll update throughout the process at significant points...
A couple of nights ago I downloaded some focussing charts and it soon became apparent that the lens is back-focussing (by about 5 cms over 10 metres).
Just to confirm this I dialled in some compensation to my Canon EOS 7D and that has improved matters to some extent (unfortunately there's little advice available as to how much or little to compensate).
Not wishing to spend weeks on a trial and error mission I contacted Sigma UK with a view to them recalibrating the lens.
They can be contacted here:
Service Department
Sigma Imaging (UK) Ltd
13 Little Mundells
Welwyn Garden City
Hertfordshire
AL7 1EW
Or, by emailing [email protected] or telephoning 01707 329 999.
They recommend sending the lens to them by courier. They quote between 2 and 3 weeks to turn the job around and a simple adjustment (to address the focussing issue) is £34.73. If they discover other problems they will quote before carrying out the extra work.
I'll update throughout the process at significant points...
Last edited: