Canon Community

ptapaskar · ‎02-23-2022

Hi

I have a canon 100 400 IS II USM lens and have recently purchased a canon 2x III extender.

I have a canon 6D mark II camera.

I need help/advice. on the following issues.

1. I cannot auto focus using the extender. In fact the autofocus option disappears once the lens and extender is mounted on the camera.

2. The pictures are a bit hazy.

3. Any other tips to take wildlife photos using the extender.

Thank you.

1.

MikeSowsun · ‎02-24-2022

Your 6D Mk II can only AF if the lens aperture is f/8 or larger. Your 2x extender doubles the aperture on your lens from f/5.6 to f11 and makes AF impossible

I would advise returning the 2x and buying a 1.4x extender which will result in a f/8 aperture and still allow AF with your camera and lens.

Any extender or teleconverter will cause image degradation but the 1.4x extenders have less degradation than the 2x. Shooting stopped down at f/11 will help.

Mike Sowsun

View solution in original post

wq9nsc · ‎05-11-2023

I don't use the 100-400 lens but every generation of it of which I am aware has a maximum aperture of f4.5 which puts it at f9 and outside of the f8 capability when using a 2X extender.

Rodger

EOS 1DX M3, 1DX M2, 1DX, 5DS R, M6 Mark II, 1D M2, EOS 650 (film), many lenses, XF400 video

normadel · ‎05-12-2023

You need to read the lens's manual carefully. This is what it says:

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help with canon 2x III extender autofocus