Which Method For Manual Focusing ?

Hi,

I have recently purchased a 1.4x extender for my 400mm f/5.6 lens and use it with a 20D camera. As I'm sure you're aware this combination only allows manual focus, unless you tape the pins of the extender.

I tried using the autofocus with the pins taped but found it to be slow and unreliable. So I've two choices; either I keep the pins taped and switch the lens to MF to utilise focus recognition, or I remove the tape and judge the focus purely by eye.

I have experimented with both, but am still not sure which one works best (although am leaning slightly in favour of judging it by eye).

Which would you recommend ?

Julian, let the pictures you take govern your judgement. What produces the best picts?

Rob...........

Hi Rob,

Thank you for your reply. At present I have not been able to see a clear and definite difference in the results, hence I asked the question.

You could try to use AF and fine-adjust manually if necessary. I didn't find the AF performance very reliable, AF oscillated quite a bit before locking.

I use my eyes as guide for years. I think people have been doing that since day one of photography. This way has worked for so many for so long, I do not see how it does not work today.

I have not had much luck w/400 5.6 and TC but you could try taping the pins then using the left-most focus selection point. Rumor has it that will work better than center-focus.

John Mc

Hi Julian Would avoid taping the pins and go with manual focus. For best result focus just past he subject then focus back and shoot at the sound of the beep .. Will be accurate !! .... btw that combination will produce very sharp results but a tripod is a must !!!

if you use a TC like the tamron sp pro and the tape trick it is pretty accurate and not really that slow, its much faster / accurate than using the canon TC from what I tested.

Hi everyone,

Thank you for the replies. Just so you know I purchased the Canon version.

Alfred; the issue I have is that with Manual Focus on this combination unless you tape the pins you don't actually get any 'beep' (focus confirmation).
And if you do enable this feature, I'm still not convinced whether it is reliably accurate.

I no longer have the 20D or 400f5.6, but when I did, I taped the pins and had good results in AF. It tracked and locked slower, but my eyesight is not up to manual focus on non live view cameras. The af was accurate with taped pins, and I even did BIF with it. I was using the Canon 1.4X new version.

Quote:

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Originally Posted by Desmond Chan

I use my eyes as guide for years. I think people have been doing that since day one of photography. This way has worked for so many for so long, I do not see how it does not work today.

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Manual focus is the only saviour when the animal is in thick vegetation. Else, I use autofocus. If you are in doubt about the reliability of autofocus with taped pins, then it is better to use manual focus. Your compositions will improve as well.

Cheers,
Sabyasachi

Are you working on a tripod????????

Hello Arthur,

Yes, I generally only use the 400 + 1.4x extender with a tripod, bean bag or resting the lens foot on something solid.

Since posting the question I have gone with judging the focus by eye, with reasonably good results (as long as the subject isn't too small in the viewfinder).

When focusing manually with any telephoto lens I believe that it is imperative to always use a tripod or another form of adequate lens support. Otherwise the natural movements of your body will cause unsharp images. In the same vein, it is always best to use AI Servo AF (C in Nikon) rather than One-Shot (S in Nikon) when you are handholding a long lens (for the same reason).