Question on 1.4 II & 2x II extenders ?

[Vic_izoita]

Hey all.
I would like to extend my zoom power for 70-200mm f4 lens that i use on my 10D. I was told that the 1.4 II extender will slow the lens down by 1 stop and the 2x by 2 stops which is fine for what I do but im just woundering if i will have any focusing or quality problems using one of these.
Some one told me that I would have auto focusing problems if i use an extender with my 70-200mm, is this true?

[tzrider]

>Some one told me that I would have auto focusing problems if i use an extender with my 70-200mm, is this true?

That's nonsense ! An 1.4 convertor gives better quality
then an 2.0 It would however be better if you had a 2.8 lens.



You might expect a small loss in quality.

Best wishes,

Jeroen

[Canuck]

Hey all.
I would like to extend my zoom power for 70-200mm f4 lens that i use on my 10D. I was told that the 1.4 II extender will slow the lens down by 1 stop and the 2x by 2 stops which is fine for what I do but im just woundering if i will have any focusing or quality problems using one of these.
Some one told me that I would have auto focusing problems if i use an extender with my 70-200mm, is this true?

The answer is yes and no...on the 1.4 no, you loose an fstop so it will be and F5.6 lens and still have AF; on the 2x tc you will loose AF as it becomes an F8 lens and the 10D/300D will not AF. However, if you have a 1 series then you could.

[SnJPhoto]

Check the notes on the compatibility charts. If I remember the issue with the 10D, it is limited to Af on aperatures of F5.6 or greater (F4, F2.8 etc etc), where-as the 1D bodies are limited to F8 or greater.

Here's a link to the B&H chart.....

http://www.bhphotovideo.com/FrameWork/charts/canon1_4xExtender.html

As for quality, I use both and have had excellent quality from both. I've even gone as far as stacking both a 1.4 and 2.0 behind a 300/2.8 for a couple really long shots.

Scott

[msnow]

I used the 2x on the 70-200 with the 10D. No loss of quality but it does have trouble auto focusing in lower light situations or if it stop down beyond 5.6.

I haven't tried it yet on my 1DMkII.

[Vic_izoita]

thanks for the feedback guys.. as soon as my 10d comes back Canon repair center i will be buying 1.4x extender..
vic

[CyberDyneSystems]

Just to clarify,

10D + 70-200mm f/4 + 1.4X T-con = Damn fine image and functioning AutoFocus :)


10D + 70-200mm f/4 + 2X T-con = O-kay but still useable image quality but NO AutoFocus :?

[defordphoto]

And anytime you use a tele-converter you will lose quality. Many times that loss can be partially, but never all, recovered is post-processing.