EOS 6D dark band across bottom of images with EF 70-300mm lens

[mjtatntrek]

Hi everyone, just started having image issues today in the form of a dark band covering about 25% of my images. It's darker at the bottom (in landscape format) and fades back to the correct colour image at about one-quarter height. If I use vertical format, the band is along the lhs or rhs depending on how I hold the camera. The annoying thing is that it only happens when I use my EF 70-300mm F4-5.6 IS USM lens with my Canon 6D body. If I use this body with a different lens - no problem. Similarly if I use the lens with a different body (my 500D), no problem. I've contacted Canon UK and have been asked to wait for their answer. Would appreciate some advice. (NB - I'm not using flash for the problem images).

[Anonymous]

I saw the picture of the EF-S lens and panicked! 

Are you using a lens hood or is the lens mounting loose allowing the lens to be tilted? 

[mjtatntrek]

Hi Bob, it happens with and without a lens hood.  I'm in contact with Canon UK about this. I've discovered that the lens might be the issue. It was purchased secondhand a few years ago and has been fine, but on closer inspection yesterday. the back ring (see image) has been rather crudely ground down by the previous owner. I feel a bit of a prat for not having properly inspected the lens when purchased. I'll let everyone know what Canon UK have to say. Cheers.

[Anonymous]

I wonder why they did that? Was that causing the lens to mount on an angle to the camera or to be loose?

[deebatman316]

That picture looks like a broken shutter. It maybe the 2nd curtain that failed not the first curtain that failed. If your using a smaller aperture the 2nd curtain will be used.

[kvbarkley]

"That picture looks like a broken shutter."

But it only happens with one lens...

[deebatman316]

That's the strange part though. I've seen broken shutters only show with slower variable aperture lenses before. But not a fast F/2.8 zoom or a fast prime lens ie F/1.2 for example. If the aperture is small a longer shutter speed is needed. Requiring the 2nd curtain to be used. If the OP has another EF lens. They could set a small aperture such as F/16 or F/22 and see if it happens again. In Auto and P modes the camera will try to open up the aperture. Before it increases the ISO which makes sense you want to use the lowest ISO to avoid noisy pictures.

[mjtatntrek]

See new images in response to 5DIV

[kvbarkley]

The chisel attack on the lens is almost certainly letting in light.

[deebatman316]

I would think so too. The lens has been modified from it's original design. It is quite possible too that the lens elements are out of alignment.

[mjtatntrek · Accepted solution]

The lens will now be sent to Canon UK for repair with an estimated cost of around $140.  Thank you all for your time and contributions. Best wishes, Mike, Wales, UK.