Keep Tamron 70-300 VC USD or get the 1.4x to go with the 70-200 II

[sagittariansrock]

So I finally upgraded my 70-200 2.8 IS to the vII, and I am faced with the following facts:

• The 70-300, while good for it's price, does not have a very fast AF.
• Since I have owned the 70-200 2.8 IS vI I have hardly taken the 70-300 out.
• 300mm @f/5.6 isn't really useful for birding- in fact there isn't really much use for 200-300mm for me on a regular basis.

So I am thinking of selling it in favor of a 1.4x teleconverter to use when needed.

Let's break down the questions:

• How is the 70-200 II plus 1.4x AF speed? Please comment on both II and III and the Kenko ones, if you have used them. [As a reference, the Tamron AF is faster than the non-L Canon but much slower than the L. More than enough for slowly moving subjects (humans) but not fast moving ones (birds)]
• Have you used more than one version of the 1.4x TC? I don't have a weather-sealed body, and I believe the II added only weather-sealing. So if there's not a world of difference between II and III, would I be fine with the I?
• Do you use your 70-300mm variable zooms (L, non-L, third party, whatever) between 200-300mm? If so, when?

As always, your input is greatly appreciated.

[Random Orbits]

Normally I wouldn't jump in on a thread when my experience is not as broad as what you're asking for, but given that some information is better than none....

What I have used:  70-200L II with a 1.4x III and 2x III and a 70-300L

The AF speed for the 70-200 + 1.4x III is fine.  Slower than bare lens but I don't find it all that noticeable.  It takes a big hit (very noticeable) with the 2x III.  I've found my 5D II to be a more limiting AF factor than the 1.4x III.  There have been multiple threads discussing converters and the overall sense of it is that the Kenko and 1.4x III are comparable but the Canon 2x III is better than its competitors.  The Kenko 1.4x is nice because it doesn't portrude out like the Canon so you can use it on other lenses (also allows TC stacking) that were not designed to work with the Canon extenders but the Kenko also is not as weather resistant as a result.

The IQ difference between the 70-200+1.4x III and the 70-300L is not very significant, but the 70-300L is more compact and lighter, which makes it a good choice for travel, zoo, etc when you know you'll be outside and don't want to be carrying a lot of gear.

[sagittariansrock]

Normally I wouldn't jump in on a thread when my experience is not as broad as what you're asking for, but given that some information is better than none....

What I have used:  70-200L II with a 1.4x III and 2x III and a 70-300L

The AF speed for the 70-200 + 1.4x III is fine.  Slower than bare lens but I don't find it all that noticeable.  It takes a big hit (very noticeable) with the 2x III.  I've found my 5D II to be a more limiting AF factor than the 1.4x III.  There have been multiple threads discussing converters and the overall sense of it is that the Kenko and 1.4x III are comparable but the Canon 2x III is better than its competitors.  The Kenko 1.4x is nice because it doesn't portrude out like the Canon so you can use it on other lenses (also allows TC stacking) that were not designed to work with the Canon extenders but the Kenko also is not as weather resistant as a result.

The IQ difference between the 70-200+1.4x III and the 70-300L is not very significant, but the 70-300L is more compact and lighter, which makes it a good choice for travel, zoo, etc when you know you'll be outside and don't want to be carrying a lot of gear.

That was very informative.
I don't have a weather-sealed body so I might seriously consider the Kenko then.
One question, though: Can you tell me when you most use the 200-300mm range in case of the 70-300L? Zoo, for one, makes sense. Anything else?

[Random Orbits]

That was very informative.
I don't have a weather-sealed body so I might seriously consider the Kenko then.
One question, though: Can you tell me when you most use the 200-300mm range in case of the 70-300L? Zoo, for one, makes sense. Anything else?

Outside sports if I know I'll be far away (i.e. from the stands and outside) and travel.  The 70-200 is a better portrait lens and sports lens and for lower light situations.  The 70-300L delivers similar IQ but in a smaller and lighter package.  The lower weight and compact size is nice when travelling with small kids because it hangs from a BR strap more comfortably than the 70-200 (when locked in its shortest position) and its smaller size (mainly length) means I can use a smaller camera bag (i.e. Tamrac Velocity 7) rather than using a much larger bag to accomodate the length of the 70-200.

[samkatz]

all I can say is that as much as I like my Tamron 70-300, it could not be slower, very useless for birds in flight.   I've used the 300 4.0 L +1.4x, it was faster.  the faster canon lens+converter might be faster, and sharper.