Canon 1x4 converter

[john starkey]

Hi all,having got my canon 100-400mm L is,which I am delighted with,I am concidereing getting a 1x4 converter for a bit more reach,can anyone with this combination give me some idea how good it is,
regards,
john.

[dod]

there seems to be mixed results, the combo I had was excellent, some samples (http://www.talkphotography.co.uk/forums/showthread.php?t=94362)

[Canon Bob]

Be aware John that you'll lose AF unless you've got a 1Ds/1D series body.

Bob

[john starkey]

Be aware John that you'll lose AF unless you've got a 1Ds/1D series body.

Bob
Thanks guys,think i will save hard for a longer lens and a 7D :thumbs:,
regards ,
john.

[beermonster65]

Slight hijack but, would a 1.4x on a 70-200 f4L auto focus still on a 50D?

[mtracerz]

Slight hijack but, would a 1.4x on a 70-200 f4L auto focus still on a 50D?

Be aware John that you'll lose AF unless you've got a 1Ds/1D series body.

Bob

Don't sound like it.

[Canon Bob]

Slight hijack but, would a 1.4x on a 70-200 f4L auto focus still on a 50D?

Don't sound like it.

Yes it will.....the 1.4x drops your f/4 lens to an f/5.6 combination.

The reason I said that the 100-400L combination won't AF is that the lens is already f/5.6 on the long end and it's unlikely you'd be using the T/C at the short end (when the lens is f/4) as the lens alone would cover that focal length.

Bob

[MartinM]

I used to have that combination.
Can't comment on the IQ, always thought it was great but never did any 'proper' analysis...
but..
the 1.4 takes it to F8 at 400mm and Canon apparently don't 'officially' support AF with that combination.
You can mask off 2 of the pins on the lens though and the AF will work Ok!
I'm sure there must be a thread on here to cover it!?
Worked fine for me!?

[micloi]

If you cover the pins AF will work ONLY if there is sufficient light and it will not be as reliable or fast