I have a Canon EOS T3i 600D. When I use a Canon-branded lens (18-55mm), the camera works well. When I change to the Sigma macro 18-250mm and turn the camera on, I can hear a ringing noise, like ...
My new Sigma 70 - 300 APO DG Macro lens zoom ring is not working after 270mm. In this situation what can I do? N.B: No external pressure is not given.
I have a Sigma 610dg super flash that I wish to trigger with the TriggerTrap flash adapter (tt-fa1). Sadly I cannot make this work. I have tried two different TriggerTrap dongles but the flash never ...