Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Dreaded err01

I used this lens for one shoot, and in the middle of the shoot I got an err01 message. Hard to imagine the contacts are dirty when you are in the middle of shooting using the same lens the whole time. In my case the error only occurred when shooting at low aperture settings, for higher apertures it worked fine. After I got the error I swapped in two other lenses, which worked without any problems.It's hard to tell in the days of the internet when you read about problems if a piece of equipment has a design defect, or if you are just reading about the small sample of inevitable failures. Having said that, if you are considering this lens do a google search for canon 24-105 err 01, here is a sample that you might start with: [...]