I have managed to clarify the situation with Sigma USA today, this is interesting info for all the D7100 users here. Here the content of the email communication with Sigma:
[h=2]Message:[/h]Hello,
can you please confirm if the Sigma 18-300 C has the same compatitbility problems with the D7100 as the 17-70 and 18-200, namely, that the OS stays active for one minute during which time endless scrolling/zooming during preview is not possible.
Many thanks in advance for your help.
Hello Martin,
This behavior is related to the operation of the OS unit of the lens when it is used in conjunction with the Nikon D7100. The OS unit stays in communication with the camera body for about 1 minute after a camera’s auto-off feature shuts down the camera between exposures while still in the on mode. This is because our lenses are designed to stand by for operation; Nikon cameras have no provision for determining the status of the OS unit. This will also cause the need to press the multi selector of the Nikon D7100 each time to scroll or zoom in when reviewing your images on the D7100 LCD screen. These symptoms only occur on the Nikon D7100 camera, there is nothing wrong with the lens. If and when you recognize the phenomena mentioned above, please note they will not cause any malfunction to the camera body, you can keep using our products without any worry.
Yours Truly,
Paul Pizzano
The Sigma Corp. of America
Hi paul.
Thanks for your very quick feedback. Does this also apply to the new 18-300?
Regards
Martin
Hello Martin,
Yes, it uses the same OS system.
Yours Truly,
Paul Pizzano
The Sigma Corp. of America