canon converter

[sailingval]

I have a 400D with 70 - 300 USM 4 - 5.6 lens. Does a canon 1.4 converter work with this or are there any other suggestions. Can't afford a 400 lens yet.

[galanthus]

I have the 400d and I too am currently longing for a 400mm, I looked into using a 1.4 extender with that and am sure I read that it isn't great with 300mm or less. tho I could be wrong, have searched back-threads for you but can't seem to find anything.

[Hobjob]

Originally Posted by sailingval

I have a 400D with 70 - 300 USM 4 - 5.6 lens. Does a canon 1.4 converter work with this or are there any other suggestions. Can't afford a 400 lens yet.

Canon say that the 1.4 convertor won't work with 100-400 pump which is 4.5-5.6, because not enough light comes in for auto-focus. I can't speak for the 70-300.

The 100-400 does work OK with 1.4 convertor if a couple of the contactsd are covered (do a google search, also been covered on this forum). In lowish light it certaiunly does hunt a bit for focus, and in good light the auto focus is slower than without the convertor.

There was a thread many months back on this forum I think talking about another convertor, not sigma, that was better both for speed and sharpness. Sorry, senior morning, can't remember but I think it began with a "k" .......... someone help me out !!

[dav56]

Originally Posted by Hobjob

Canon say that the 1.4 convertor won't work with 100-400 pump which is 4.5-5.6, because not enough light comes in for auto-focus. I can't speak for the 70-300.

The 100-400 does work OK with 1.4 convertor if a couple of the contactsd are covered (do a google search, also been covered on this forum). In lowish light it certaiunly does hunt a bit for focus, and in good light the auto focus is slower than without the convertor.

There was a thread many months back on this forum I think talking about another convertor, not sigma, that was better both for speed and sharpness. Sorry, senior morning, can't remember but I think it began with a "k" .......... someone help me out !!

Just read your post. I have a 100-400 and was looking at getting a 2.0 converter, would I have the same problem with that?

[Words]

The converter beginning with 'k' is the Kenko. Beyond that, I can't help much as I'm also wondering whether to get a converter for my set-up - 400D + 100-400mm. My main worries are that I seem to recall reading that the image stabilization struggles with this set-up, which means getting a tripod, which means I won't use it that often. Here's the earlier thread that got mentioned.

[zan]

Canon cameras (at least the consumer\prosumer ranges) need a minimum aperture of 5.6 if the autofocus is going to work. Adding a 1.4x converter decreases your lens aperture by 1 stop; adding a 2x converter drops it by 2 stops:

i.e.

a. 100mm F4 lens + 1.4x converter = 140mm F5.6 lens
b. 100mm F4 lens + 2x converter = 200mm F8 lens
c. 100mm F2.8 lens + 2x converter = 200mm F5.6

in (a), the autofocus will work, but not in (b) because the aperture is now too small. (c) works fine because the lens was faster to begin with. Incidentally, all lenses will still take photos, but (b) now has to be manually focussed.

So that's something to consider.

Adding a converter will also reduce the image quality by a certain amount, largely depending on the quality of the lens you're extending. An 'L' series lens will show much less degradation than a £50 lens.

they are also designed to work better with longer lenses, although I don't know any minimum focal length recommendations off the top of my head. I know converters are often used with the 70-200mm canon lenses though and are fine.

Hopethis is some help (and makes sense!)

Zan

[colincurry]

I have a 100-400 plus a taped canon 1.4 converter.

It works quite well and the AF is not too bad. I did manage some quite clear pics of flying lapwings, but could not focus on a fieldfare that flies like a bullet.

It is always a compromise. I have got reasonable snaps using the converter that I ould not have got near without.

Something that I did not fully appreciate is that 100-400 has two AF settings. I always kept it on the 1.9m to infinity setting, not realising that this slowed down the AF on subjects more than 6.8 metres away (the other setting); or that the opposite applies in that you cannot focus properly on closer subjects using the 6.8m AF setting. Senility rules.

Perhaps the answer is to find a friend who has a 1.4 and to try it. John - who is a most experienced birder swears by the combination.

Colin

[genuinita]

canon 1.4x & 2x extenders only fit on the following (canon) lenses:

135/2
180/3.5
200/1.8
200/2.8
300/2.8
300/4
400/2.8
400/4 DO
400/5.6
500/4
600/4
1200/5.6
70-200/2.8
70-200/4
100-400/4.5-5.6

you'll need to use a non canon (eg sigma) teleconvertor for any other lens

hope this helps

[sailingval]

Thanks for all the feedback.

I guess I'll have to crop and save my money for a larger lens.