[NEWS UPDATE 4 DECEMBER: Sigma says a similar glitch also affects Nikon Df users. For details see the Sigma Japan website]

Commenting on the ‘phenomenon’, Sigma said in a statement: ‘Without the latest firmware, the OS and Live View Auto Focus functions do not work properly when… used with the Nikon D5300.’

The problem affects Nikon lenses with an internal motor, adds Sigma which warns that the firmware update may not be possible with some discontinued products.

Sigma says it will offer a free firmware update from tomorrow (20 November) for customers who own Nikon-mount Sigma lenses.

All new lenses will include the updated firmware, the company says.

Customers who need to have their lenses updated should call Sigma Imaging (UK) on 01707 329 999 or email service@sigma-imaging-uk.com