recently I've noticed an issue with my Tamron lens (at least I think it's the lens). My current set up:

  • Canon EOS 90D
  • Tamron AF 70-300mm f/4-5.6 Di LD Macro

When taking photos at the 300mm end of the focal length the camera throws an error:

Err 01 Communications between the camera and lens is faulty. Clean the lens contacts.

I've checked the gold connectors, they are clean (gave them a gentle clean anyway with a cloth).

What makes it strange is that this only happens with this lens, and only close or at the 300mm end of the focal length, anything between 200-300 is likely to cause the error. It's not consistent, sometimes I can take a couple of photos before the error shows up.

I've also sometimes noticed that the issue shows up purely by focusing on something in the distance, before I even take the shot.

If the photo is captured it is horribly overexposed - regardless of settings. I've tried to replicate it in a consistent manner but there isn't a pattern to it.

As a test, I've taken two photos one after another (within 10 seconds in this example), using the exact same settings, only changing the focal length.

  1. 1/100sec f/11 ISO100 176mm Good Photo

  2. 1/100sec f/11 ISO100 300mm Bad Photo

I've been using this lens since March 2020 (bought it brand new), with no issues up until last few days.

Anyone had a similar issue?


2 Answers 2


This was going to be a comment.

As the lens is extended, the "lever arm" gets longer. Maybe the rear lens flange is a bit loose and is creating a gap at the longer focal length leading to improper electrical connection.

I would recommend close inspection of the lens to camera connection as the lens is extended as a first step.

  • 2
    \$\begingroup\$ To confirm this hypothesis, see if the problem disappears when the lens is pointed straight up, or worsens when you shoot downwards. \$\endgroup\$
    – xenoid
    Commented Oct 10, 2021 at 10:37
  • \$\begingroup\$ If the lens-side part with the contacts on it is easily unscrewed, shimming it with something like washers, polyimide tape, thin fibreglass circuit board pieces ... could help (or create more problems). \$\endgroup\$ Commented Oct 10, 2021 at 16:43
  • \$\begingroup\$ @xenoid - Have tried it pointing upwards, downwards and at angles, with different focal lengths but it's the same story. As soon as I turn to 300mm it shows the error. \$\endgroup\$
    – Kamil
    Commented Oct 11, 2021 at 10:48
  • \$\begingroup\$ There isn't any movement I can see, no gaps. The lens sits as tightly as my other lenses. \$\endgroup\$
    – Kamil
    Commented Oct 11, 2021 at 10:53
  • 1
    \$\begingroup\$ @Kamil on US eBay, a used replacement is less than $100. The lens is broken. \$\endgroup\$ Commented Oct 11, 2021 at 17:43

My guess is that some electrical connection inside the lens looses contact in some mechanical situations, maybe getting stretched when going beyond 200mm focal length.

The over-exposure might come from such a faulty internal connection: the iris not closing, thus taking the photo full-open at f/5.6 although commanded to do f/11. This would result in a two-stop over-exposure, and could explain your bad example image. You could do some tests in Av mode, set to f/5.6 (they should all come out good), and f/16 (some / many / all of them should be badly over-exposed).

I wouldn't take the wording "Clean the lens contacts" in the error description too seriously. I bet this "Err 01" comes in almost every situation where the lens doesn't respond as expected.

  • \$\begingroup\$ I have noticed an old query with a similar issue, altough with a different lens model. Canon EF-S 55-250mm f/4-5.6 IS II causes Err 01 only when zoomed beyond 135mm I suspect it could very well be a similar problem with my lens. As @Bob Macaroni McStevens said above, a replacement might be easiest option, since the lens itself is not one from the expensive range. I will try your suggestion with Av mode while looking for a replacement just in case. \$\endgroup\$
    – Kamil
    Commented Oct 11, 2021 at 21:40

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