Taping the pins on Canon extenders

[matt_xyz]

WW, you tape the pins to trick the lens into autofocusing. Otherwise the autofocus shuts down when you fit a teleconverter to a lens that is f5.6 or slower (now you wish you hadn't asked )

You can use clear tape.

I believe the AF doesn't shut down on pro bodies, so I think Dai is right. But pro bodies have no crop factor, or 1.3 crop factor, so need a TC more than consumer bodies do!

If you read the various photography forums, it seems the success of the pin-taping trick really varies from individual to individual. It doesn't work well on the 400 f5.6 (AF really hunts and oscillates) although I recently read of someone who tried it on 2 different 400 f5.6 lenses, and it worked OK on one but not the other More success seems to be had with the 100-400 although it seems difficult to explain why this would be. Others have reported different success with different camera bodies

Matt

[Boddie]

Mine works great in subjects of high contrast, such as a swan on a lake for example, but in trees its not so good. It'll hunt for ages and the trick is to keep half depressing the button. For me the exteder is well worth having but dont expect miracles in every condition

[Wild-Woman]

Originally Posted by matt_xyz

WW, you tape the pins to trick the lens into autofocusing. Otherwise the autofocus shuts down when you fit a teleconverter to a lens that is f5.6 or slower (now you wish you hadn't asked )



Matt

Thank you Matt. I do 'get it' a bit. It's the only way I can get my head around all this camera stuff. Thank you for taking the time to explain.

[Jon]

For what it's worth I have taped my canon TC and use it very occasionally on the 100-400L IS lens. I cannot rely on functionality, after all canon never claimed to say the the 100-400L IS would auto focus with a converter.
Similar to Matt the auto focus only works on high contrast subjects and on bright days. I find if I cannot auto focus it is not worth using the TC as I find precise focus by naked eye too unreliable. I have seen very few good shots using the 1.4 TC and the 100-400L IS combination, some photographers claim it is better to avoid the TC and crop instead.
For me the jury is out I have not really given the TC a fair chance as the weather conditions are not usually good enough. The biggest supporters of the combination seem to be from the USA where there is frequently much more light. Jon

[colincurry]

I am stll in the process of testing Cordless Dave's 1.4 with my 100-400. It seems to be Ok with pretty static subjects and not so good with with flying birds. I tried to track a barn owl against a darkish background and bobbing in and out of trees - no good at all. I also tried fairly long range B H gulls and the results were OK but not worth keeping. However, I did manage to catch a good kestrel against the sky. I have used clear tape - sellotape in fact. It seems at the moment that its strength for me would be to bring distant objects nearer; but these would have to be fairly still and relatively clear. I shall carry on testing. I am due to go to Slimbridge at the end of the month and would like to try one for the bittern - but Dave will be away and using his converter. Currently, I am unconverted. Most of my birding is done walking around the countryside and not from hides, which is where I think the 1.4 would score in my case.

Colin

Colin

[Jon]

Originally Posted by colincurry

I am stll in the process of testing Cordless Dave's 1.4 with my 100-400. It seems to be Ok with pretty static subjects and not so good with with flying birds. I tried to track a barn owl against a darkish background and bobbing in and out of trees - no good at all. I also tried fairly long range B H gulls and the results were OK but not worth keeping. However, I did manage to catch a good kestrel against the sky. I have used clear tape - sellotape in fact. It seems at the moment that its strength for me would be to bring distant objects nearer; but these would have to be fairly still and relatively clear. I shall carry on testing. I am due to go to Slimbridge at the end of the month and would like to try one for the bittern - but Dave will be away and using his converter. Currently, I am unconverted. Most of my birding is done walking around the countryside and not from hides, which is where I think the 1.4 would score in my case.

Colin

Colin

I hope you are right Colin but I suspect you will be disappointed if you are relying on auto focus for quickly grabbed shots. What may be worthwhile considering is setting the lens a bit shorter than 400mm, then the aperture would be slightly wider than 5.6, this may improve functionality but of course you would lose a bit of focal length still 350mm plus 1.4TC is quite a decent focal length. Jon

[Hobjob]

Originally Posted by Boddie

The question of how to tape pins on the Canon extenders, so that the AF still works, gets asked quite often on WAB. So I have written the answer on my own website.

Andrew Hunter Photography: Tips: Canons 1.4 X and the taping of pins

Thank you - very clear - a picture is worth a thousand words!