What teleconverter to get?

[jackley]

I have a 20D, 70-200 f4L and like to shoot motor sports (motorcycle/car racing).

I'm thinking I would like a bit more zoom.

Which one of these would you suggest or should I get a different one?

Tamron SP Pro 1.4/2.0x
Canon 1.4/2.0x

1.4x vs. 2.0x?

Canon vs. others?

thanks.
james

[Transfix]

I'd stay away from the Tamrons.

Get the Canon 1.4x II.

The Canon 2x II will disable your ability to use AF. AF and a 2x converter will only work if the maximum Av is 2.8 or better.

[tofuboy]

I can't recommend which brand to get as I have no experience with either, but as Transfix said, the 2.0x converter will make it so you can't autofocus... probably not a good thing when shooting motor sports. I've heard the 2.0x converters degrade photo quality a noticeable amount as well. The 1.4x will as well, but not as much and people seem happy with it's results.

[Cadwell]

The Canon 1.4x is a good bet. The Sigma 1.4x EX also works well on the 70-200 f/4L. I'd stay clear of the 2xs from any manufacturer. I don't find the image quality with them acceptable.

[iwatkins]

Canon x2.0. does the job (even if you loose the AF) but it does degrade the image quite a lot. Even so, I still find it useful. The canon x1.4 is much better, but of course you don't get the mag.

If you are serious about more zoom, consider the 100-400L IS. It is very good, but isn't cheap.

Cheers

Ian

[jackley]

Thanks for the info.

Looks like I'll just go with the 1.4x. I didn't know about loosing AF, definitely can't do that.

[Phil Hall]

I use the Canon 1.4x with the 100-400 works great everytime.

[blackviolet]

i've got the tamron sp 1.4x and it's much better than its cheaper brother. i'd like to see a side by side comparo between this and the canon with the same lens and body.

oh yeah, and it's the same colour as the canon ;)

fwiw it allows af with most lenses...

[robertwgross]

In a recent photo article, George Lepp made the comment that a good x1.4 teleconverter will ruin the sharpness by 10% and the good x2 teleconverter will ruin it by 20%. However, I don't know exactly what those percentages mean on a real image.

It has also been said that if you start with a soft long lens and apply a teleconverter, you get the softness magnified into a blurry mess. If you start with a very sharp long lens and apply a good teleconverter, you can still maintain a fairly sharp image. I've found this to be accurate for me.

Note that the Canon x2 and x1.4 teleconverters do not fit many lenses. Whereas, the non-Canon teleconverters do.

---Bob Gross---

[Belmondo]

I don't understand the math involved in his comment, but in my opinion, the image degradation using the 2X converter is a heck of a lot more than twice that of the 1.4X. I could be wrong. (and often am).

[Cadwell]

I don't understand the math involved in his comment, but in my opinion, the image degradation using the 2X converter is a heck of a lot more than twice that of the 1.4X. I could be wrong. (and often am).

I have to agree with you. I own both the Canon 2x TC II and the Sigma EX 2x TC. I'm not impressed with either of them.

[CoolToolGuy]

I have the Canon 1.4x II, and I use it with the 70-200 f4L without hesitation. With my 135mm f2L it has even made me think twice about buying the 200mm f2.8L.

Have Fun,