Canon 100-400 + 7Dmkii Err 01

Discussion in 'Beginner Questions' started by lisa_steiner, May 4, 2022.

  1. Hi,

    I have a 7D MKii and a 100-400 IS ultrasonic lens (not the II) and have just started getting an intermittent Err 01 message stating that "communications between the camera and the lens is faulty" and to clean the lens contacts.

    As far as I can tell the contacts are clean, but I wiped them with alcohol yesterday and am still having the problem. They are both 4 years old and have been used exclusively in a maritime environment, without any problem up until yesterday. I was hoping to get another year out of them, before having to replace.

    Is there anything else that I can try to clean the contacts with? Or is the problem likely to be something internal??

    Any advice greatly appreciated, because after 2 years without a job, I don't have the money to replace them! I think it is just the lens that has the problem, since my 18-200lens seems to be fine.

  2. Given the circumstances you might try a little more aggressive use of a non-gritty eraser on both the camera (even though the 18-200 works) and the lens contacts. Not too aggressive, though!

    That "maritime environment" is troubling.
    Last edited: May 4, 2022
  3. Thanks for the tip, I will give it a try. I study whales & dolphins, so marine environment is mandatory! :)
  4. Here some serious marine damage from a no-longer extant site

    In my field (archaeology) the problem is usually dust and grit.
    lisa_steiner likes this.
  5. Dustin McAmera

    Dustin McAmera Yorkshire, mostly on film.

    ..and curses, and Nazi rivals, surely, not to mention losing your hat?
    Tony Parsons likes this.
  6. For d*mn sure. Especially those Nazis.

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