Q. re Autofocus on 500/4.5 lens with 1.4x extender

Hi

For a few £100's a friend and I through various sources have bought 3 No. Canon EF 500mm f4.5L lenses in various states of disrepair, they are currently in the hands of a Canon technician who is pulling them apart for refurbishment, the plan is to get 2 good lenses out of 3 sets of parts, and then purchase a few new lens hoods for £320 each!!!(which are missing)..(I do believe that a bar of Gold is cheaper than a new canon lens hood )

On the 500mm 4.5 lens I am sure the autofocus will work with a 1.4x extender on a 1-series body, but if I attached a 1.4x extender to an EOS 5D / 40D will the lens still autofocus..if not which of the lenses pins do I have to remove/tape up to make it do so?

Thanks in advance

AF only works on a 1 series body with the center AF point. It is considerably slower than using a 1.4x with the f4 model.
Tape the last three pins and you should get AF (of a sort) but it will tend to hunt for focus in all but the best light/contrast situations.

Manual focus is so easy with the old 500s that I'd have no hesitation using it over a very slow AF

Good lens though, and the two I've had in the past were pin sharp.


John

Cheers John

I bet that when used with a 1.4x the 500mm still focuses faster than the 300/2.8 with a 2x, which can be woefully slow

I guess the 500/4.5 on the 40d will give me enough reach for the hides at slimbridge where I was always used to my 1d2 on the 500/4 + 1,4x which had just enough reach from the hide, then I had to sell it.. ...still trying to get back to where I used to be but with very little money!...the plus point of the 500/4.5 over the 500/4 is the weight nearly, it's .8kg lighter which is good for my arms when hand holding for flight photography...

Hi Larry,
I would just stick a non canon extender on, something like the kenko ones(non pro), it will not report back that it's there and hey presto autofocus

Brian
(ps it should not slow the focus down too much either not like the canon ones do)

The 500/4.5 with a 1.4x is a lot slower than a 300/2.8 non IS with a 2x.

John, it will be slower if you use the canon 2x on the 300mm 2.8L non IS, but if you try a non canon version you will see a marked improvement with focus speeds. This is to do with it not reporting back to the body that it is there in the same way canon extenders do. I think you can have upto a 75% loss of speed using the canon 2x. I would expect the 500/4.5 with canon1.4x to be very slow then if is worse than the 300mm + 2x, but maybe it will not be as bad with a non canon extender!
Brian

Hi Larry

See Tip 1) here ;

Fred Miranda Tips

cheers

Sean

Thanks Sean, it's amazing what a piece of sticky tape can do