Originally Posted by
mikel51
I just returned from my annual windsurf trip to Baja. This was my first trip with a canon DSLR (EOS 30D) using a 70-300 canon IS zoom with or without a tamron 2X doubler. The focal lengths 140-600 using the doubler were about right (most shots between 250 and 600, with 450-600 being the most common). I loved the camera, and I could get much better pics than with the point and shoot olympus I have been previously using.
The one problem I had is that the autofocus doesn't work with the tamron doubler (2X). When i returned from the trip, I investigated the canon 100-400 zoom, hoping that I could pair it with a 1.4X teleconverter. Apparently, this just exceeds the limits for auto focus to work.
So--I would really like a zoom with a 200-600 range, but I also really like autofocus. I do like image stabilization as well, but it may not be necesary as most of the windsurf pictures will be in bright sunlight. Small and light is also a big plus (a nice feature of the 70-300 mm lens) so I can go handheld.
Any recomendations about how to proceed would be appreciated.
No 1.4 or 2X extender will work with the 30 D and the 70-300mm
f/4.5-5.6 DO IS USM lens. Auto focus will only work around f5.6. The Canon 1.4X converter will not even fit that lens.
I have a 70-200mm f/2.8L USM Lens and the 1.4 works perfectly.
To do what you want, you will need to shell out the bucks for the 2.8 zoom or a prime lens like EF 300 or 400 2.8
Dont forget, you are already getting a 1.3 or 1.6X (I forget which on the 30 D) boost do to the crop factor of the sensor.