I am considering buying a Canon 1.4 extender to use with my 6D and 100-400 IS L II. I understand that AF will not function with this combination.

I understand that lack of AF will limit me to static or slowly moving subjects. Nevertheless this could still be a big bonus in some situations. Does anyone have any advice based on usage of this actual combination to confirm that manual focus is a viable proposition?

  • 1
    \$\begingroup\$ Hello David, welcome to photo.SE! You already mention the drawbacks, so your question sounds very opinion based. Some people might tell you how this is easily a handholdable manual focusable kit while others will tell you that there's no way you could possibly use manual focus. There's no way around trying it yourself. \$\endgroup\$
    – null
    Aug 31, 2015 at 21:04
  • \$\begingroup\$ Hello David, welcome to SE. What kind of advice would you like to get ? Is it about image quality, camera settings, situations where the AF-less 560mm is of use... ? It may help to know what kind of pictures you want to take (bird ?). \$\endgroup\$
    – Olivier
    Aug 31, 2015 at 21:11
  • 2
    \$\begingroup\$ Given the subjective nature of the question (how good is good enough?), I'd suggest renting a TC if you can and try it out for yourself. Having tried a 1.4 TC on the Mark 1 version of that lens, I was really unimpressed with its performance with moving subjects, and I've not yet found a great opportunity to try again with a static subject. \$\endgroup\$
    – D. Lambert
    Aug 31, 2015 at 21:46
  • \$\begingroup\$ possible duplicate of Can manual focus be faster than autofocus? \$\endgroup\$ Sep 1, 2015 at 13:57
  • \$\begingroup\$ I suggest that this question is really about whether manual focus is a viable option over slow autofocus, which is why I marked this question as a duplicate. \$\endgroup\$ Sep 1, 2015 at 13:58

1 Answer 1


I have a 6D with the old version of the 100-400. Focusing for me in manual mode is difficult and hit or miss. If I focus manually I try to let the camera focus points tell me if I am in focus. It doesn't always work if the background is high contrast. If I have a subject that is very high contrast that helps a lot and my keeper rate goes up.

If you can put the camera on a tripod then you can focus with live view. Use the camera display zoo to zoom in. This works quite well for stationary subjects. I bought a hoodman to focus in live view in bright sunlight. It helps a lot.

  • \$\begingroup\$ Thank you Alan for your help. The tips on manual focussing are much appreciated. I don't much use a tripod. As a member of my local Photo so, I enter all their competitions and some external salons with some success but in all subjects not just Nature. Thanks David \$\endgroup\$ Sep 1, 2015 at 15:41

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.