For any long-distance filmmakers (or, you know, wedding or event covering videographers), Canon’s top-end super-telephoto lens line are some of the best options available for shooting tight in large spaces (also, some of the most powerful and expensive by far). Which makes this news a little alarming for any owners (or, more likely, renters) of these two Canon lenses…

Canon released a product advisory for the Canon EF 400mm f/2.8L IS III lens and the Canon EF 600mm f/4L IS III lens. Here are the details.

Canon Super-Telephoto Product Advisory

Canon Telephoto

Canon reports that there have been issues with a phenomenon being created “where the exposure may flicker slightly if recording a movie with the camera shooting mode set to M or Av in combination with select cameras.”

The “select cameras in question include:

EOS-1D X Mark II, EOS-1D X, EOS-1D C, EOS-1D Mark IV, EOS 5D Mark IV (Ver. 1.0.2 or later), EOS 5D Mark III, EOS 5D Mark II, EOS 5Ds, EOS 5Ds R, EOS 7D Mark II, EOS 7D, EOS 6D, EOS 80D, EOS 60D, EOS 60D, EOS 60Da, EOS 8000D, EOS Kiss X 90, EOS Kiss X 90, EOS Kiss X 80, EOS Kiss X 50, EOS Kiss X 8i, EOS Kiss X X7i, EOS Kiss X7, EOS Kiss X6i, EOS Kiss X5, EOS Kiss X4, EOS M, EOS M2”

While firmware appears to be on the way, Canon recommends two ways to avoid this issue:

  1. When shooting movies, set the camera’s shooting mode to P or Tv mode.

  2. When using the lens alone or with the EXTENDER EF 2x, set the exposure setting step to 1/2 or 1/1 with the camera’s custom function, even if the camera shooting mode is M or Av.

We’ll keep you updated as to when this firmware update will be released. In the meantime, concerned video professionals might want to double check their camera and lens setup and reconsider some choices if either of these lenses are set to be used anytime soon.