Canon 400mm F5.6
 

I get my new lens tomorrow it is the Canon 400mm F5.6 Prime does anyone know what converter will still allow AF or will I still have to tape the pins. I am all excited.

Hi, as I understand it only the Canon 1.4 converter will allow AF, enjoy the lens, can't wait to see some results, John
P.S. My information came from Jessops when I enquired about the same lens.

I will still give a go with the taped pins I have a kenko pro 300 and it works all be it slow on the 100-400 canon. I have just had tracking confirmation that its on its way.:D .

Another case of wrong information given out by Jessops.

More to do with the camera body. 20D,30D,350D and 400D has a AF limit at f5.6 so your have to do the tape trick to maintain AF. I think your find the 1D bodies have a limit of f8 so it would take the 400 f5.6 + x1.4 and still AF.

For the 20D the AF working range of light is EV 0.5 - 18

For the 1D the AF working range of light is EV 0 - 18

Christine ,a great lens,very easy to handhold.Yes,you do need to tape the pins if you want to use AF with the 1x4.I have been out and about today using the 2x ,with MF and a tripod.Not very good,but it was worth a try.All my KF pics on BF were taken with this lens,and most of them in not very good light,but they came out ok.Just make sure you use the 1x4 in decent light,it does help.

I believe any lens with F/2.8 is compatible with 2x extender Version II to give full AF (A tad slower than if extender not used).

1.4 x gives AF on some EOS bodies at F/5.6 this is lens dependent also.

400mm F/5.6 L gives you AF with 1.4x if it is used on 1D, and manual focus if used with other bodies including 30D and 5D.
2x is only operable on manual, no matter what combination, when used with this lens.

You don't need to tap the pins as the pin coupling for electrical confirmation of focal length should function as usual. Taping is needed when you use the extender with a manual lens on adapter such as FD. In that case the chips in body gets confused of the lens' focal length, thus giving you error I believer 01.

The reason to use a prime lens is the extra ordinary sharpness it offers. Do you really want to decrease it by extender? Also don't forget the 2 stop drop in x2 that can turn a lens into very handicap if light not friendly, in addition to difficulty focusing manually due to very dark view finder. I wish the new DSLRs could incorporate some sort of prism split etc for old fashion manual focus confirmation or at least one such changeable optional viewfinder screen.

Hope I have not confused you.:)

I frequently use this lens with a Canon 1.4 tc on a 350D. To achieve AF you must tape the last three pins on the converter thus fooling the camera into thinking there is no TC present. The only TC which will achieve AF without taping the pins (on a non 1 series body that is) is the cheap 4 element Kenko/Tamron but trouble is this is a poor quality converter.
AF with the pins taped can be a lot slower than normal and will sometimes 'hunt' quite a bit. I have found there are a few ways of overcoming this:-
1) By manually focusing near enough and then using the AF for the final focus.

2) When the AF starts to 'hunt' take your finger off the shutter release and depress again - it will almost always lock on right away by using this method.

First photo taken today in between showers with the lens..

Nice start with the new lens Christine - I am sure you will be very happy with this lens, especially when the light gets better.

Thanks Roy its not been the best of days to try things out. I did try with the 1.4 converter, its still very sharp but no AF unless I tape the pins. I may give it a try as I am not the best a manual focusing.
I think will have to master my stalking technique so I can get that much closer.