2x converter for Canon 300F4 is (1 Viewer)

I believe there is a 2x converter which will autofocus with the Canon 300F4 lens.Is it the Tamron or the Kenko(may have that wrong,sounds like a brand of coffee!!).Has anyone used these converters,and do they make the image worse than if one was manual focussing with the Canon2x.The only reason why I ask,is,I am not very good with MF,too unsteady,but I have heard,that there is a 2x converter which will autofocus-I think.
thanks Christine.

christineredgate said:

I believe there is a 2x converter which will autofocus with the Canon 300F4 lens.Is it the Tamron or the Kenko(may have that wrong,sounds like a brand of coffee!!).
thanks Christine.

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One or more of the specific brands of teleconverters you mention may simply fail to provide full electrical compatability with Canon lenses and therefore they fail to report their presence which causes the camera to report the wrong focal length and to attempt to autofocus. The same thing can be done with any teleconverter and small piece of tape on the contacts. Rather or not it is successful in focusing depends on several things.

Using the Canon 20D with your 300 f/4 lens as an example.

The 20D requires a lens with a minimum f/5.6 to autofocus.
Adding a 1.4x teleconverter to your 300mm lens you would have a f/5.6 combo that should autofocus in most situations.
Adding a 2x teleconverter to your 300mm lens and you would get a f/8.0 combo that (if not reported to the camera) will still fail to autofocus in all but the best of situations. (if the camera is aware of the f/8 it will not even try to autofocus)

A 1.4x adds a full stop to your lenses. (f4 becomes f/5.6) (f/5.6 becomes f/8)
A 2x adds 2 stops. (f/4 becomes f/8) (f5.6 becomes f/11)

Other cameras have other requirements for autofocus. The Canon 1 series cameras will autofocus with a f/8 or faster lens.

It depend on which body you have. The 5D, 20D and such can only focus reliably up to F 5.6. The pro bodies, all the 1 series can focus up to F 8 (with the center point) so you will be fine with the f4.0 and any 2x converter. You can also tape the contacts over which identify the converter and get auto-focus on the non-pro bodies but from what I've heard it is a very poor experience with very slow and hunting focus. Not worth it.

More to the point is wheather you want use a 2x converter of any stripe. The image quality really, really tumbles with any of them. The fine datail that is so important to bird photography suffers badly. I would only use a 1.4x converter myself as they give up little in the way of quality.

Lastly on the converters themselves: there are two versions of the Kenko and the pro is up there with the canon as far as quality but the cheaper ones are very poor. (I've tested all of these back to back.) I would give the Canon the slightest edge but the Kenko have the advantage that they work with more canon lenses than the Canon converter does.

Why not spend about $700 more and buy the 400 f 5.6 ... and then later a 1.4x converter. You pictures will thank you for it
Good luck.

Christine i may be wrong but any 1.4x converter should still autofocus with the Canon 300, the Kenco pro 300 DG or the Canon are the best.Dont bother with the 2x the image quality does drop off with the 2x.Let us know what you choose

Thanks everyone,yes the 1x4 does auto focus perfectly,in fact I leave the converter on the lens all the time.Using manual focus with the 2x if it is very sunny and the image is largish,the result is acceptable.I have given up with the Canon 400F5.6.I changed the Sigma 300F2 for the Canon 300F4 IS,as I do like this little lens ,regret selling the prev one,so I am staying with this lens.Obviously no use looking for another converter,so again,thanks everyone.at least with this lens I can handhold if using the 2x,with the 400 that would be out of the question as it does not have the IS factor.I know some people say it does not make any difference,but im my case it definitely does.

Some of the Kenko/Tamron converters have working autofocus at f8 with 20D (and other cameras). It's not full speed, but some people are happy with it vs manual focus.

You can get your Canon converters to act in the same way by using the old 'tape the pins' trick as shown here:

http://www.fredmiranda.com/TipsPage/index.html

christineredgate said:

Thanks everyone,yes the 1x4 does auto focus perfectly,in fact I leave the converter on the lens all the time.Using manual focus with the 2x if it is very sunny and the image is largish,the result is acceptable.I have given up with the Canon 400F5.6.I changed the Sigma 300F2 for the Canon 300F4 IS,as I do like this little lens ,regret selling the prev one,so I am staying with this lens.Obviously no use looking for another converter,so again,thanks everyone.at least with this lens I can handhold if using the 2x,with the 400 that would be out of the question as it does not have the IS factor.I know some people say it does not make any difference,but im my case it definitely does.

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Hi Christine
What were your reasons for selling the Sgma 300mm f2. I am interested because I am considering this lens; ie weight, picture quality, lack of IS etc
Any info greatl appreciated

Patrick

TwoDogs said:

Hi Christine
What were your reasons for selling the Sgma 300mm f2. I am interested because I am considering this lens; ie weight, picture quality, lack of IS etc
Any info greatl appreciated

Patrick

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Patrick,this is a very good lens. I missed not having the IS and if needed I can always put the 100-400 on a tripod and use a 2x converter.But the image quality from the Sigma is good,and there was instant auto focus using the 1x4 converter.What I really need is a 500mm lens which will give reasonable shots using a 1x4.But all I could afford or lift would be the Tamron 200-500 or the Sigma 170-500.But I am wary of purchasing either of these as I do not want to waste any more cash buying and re selling lenses.So I am waiting awhile.
But,yes ,if you have the chance of the Sigma to try,give it a go,you will not be dissappointed.In fact if you go to the Gallery and type sigma 300 into the search bar,you will find some very good shots taken with this lens.I think"Doc" is one of the contributors.

Ragna said:

Christine i may be wrong but any 1.4x converter should still autofocus with the Canon 300, the Kenco pro 300 DG or the Canon are the best.Dont bother with the 2x the image quality does drop off with the 2x.Let us know what you choose

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There is a drop in quality with the 2x, but it is till capable of more than acceptable images with a good lens such as the Canon 300 f4. Understandably some people don't like (or can't be bothered with) manual focus, but its still possible to get good pics without auto focus if you try.

http://www.birdforum.net/pp_gallery/showphoto.php/photo/81724/sort/1/cat/500/page/1
Here's one which is taken with the 2x AND handheld - not a great image, but definitely shows that sharp images are possible, and the 2x is worth considering if you're willing to try a bit of manual focus and want the extra reach.

Cheers

K

http://www.birdforum.net/pp_gallery/showphoto.php/photo/63846/sort/1/cat/500/page/1

Here's another one taken with the 2x - could be worth considering for those more distant birds!

K

christineredgate said:

Patrick,this is a very good lens. I missed not having the IS and if needed I can always put the 100-400 on a tripod and use a 2x converter.But the image quality from the Sigma is good,and there was instant auto focus using the 1x4 converter.What I really need is a 500mm lens which will give reasonable shots using a 1x4.But all I could afford or lift would be the Tamron 200-500 or the Sigma 170-500.But I am wary of purchasing either of these as I do not want to waste any more cash buying and re selling lenses.So I am waiting awhile.
But,yes ,if you have the chance of the Sigma to try,give it a go,you will not be dissappointed.In fact if you go to the Gallery and type sigma 300 into the search bar,you will find some very good shots taken with this lens.I think"Doc" is one of the contributors.

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Many thanks for that Christine
Patrick