A good reason to reconsider a " Super Zoom "

As a matter of fact, I used to own the Sigma 135-400mm at one point, and it is a great lens optically. What lets it down, IMO, is the handling, and that is why I sold it! I just couldn't get used to using it alongside all my Canon gear (zoomed the wrong way, all the actions were stiff, no USM, and very front-heavy). That said, if I needed a zoom in that range and didn't have the money or didn't need IS, I'd certainly consider the Sigma before the 100-400mm IS. But only if I needed a zoom in that range. The Canon primes are much better optically than both those zooms.

This is an interesting thread. I'm wondering what input is offered on the decision I now face: do I buy the 70-200 mm f/2.8 L USM with a 2x teleconverter, or do I buy the 100-400 f/4.5-5/6L IS USM? I'm inclined towards the smaller lens with the teleconverter, and would appreciate any thoughts on what I trade off, etc.

laurelfink,

I'd choose the 70-200/2.8L and a 1.4x teleconverter to start off with. I'd only get the 2x is you absolutely have to have 400mm reach (the 1.4x gives you much better image quality).

Going with the 70-200/2.8L gives you more options than the 100-400 IS. Wider aperture up to 200mm, much better image quality when you use the 70-200 alone, etc.

The two lenses are not really comparable because they have different uses. If you need 400, get the 100-400 or the 400 prime. Do not try to convert the 70-200 into a 400. The quality, though still okay, is not acceptable for a pro quality lens and you will more than likely be disappointed.

I have both the 70-200L f2.8 IS lens which is Canon's finest zoom they make. And I also have the 100-400L IS which is Canon's most underrated lens. Take a peak at these two (EDIT: Okay, 4 galleries) galleries before you make your decision:

100-400L IS: http://racefamily.raci​nglines.com …/Portland/3_Day​/index.htm
(Note that these photos have been post-processed) These two other galleries have no post processing whatsoever:
http://racefamily.raci​nglines.com …Portland/Friday​/index.htm and
http://racefamily.raci​nglines.com …rtland/Saturday​/index.htm

This gallery was with the 70-200L f2.8 IS and the 1.4xTC:
http://racefamily.raci​nglines.com …ntBoats/Marsing​/index.htm
(Note that there was no post processing on any of the photos in this gallery)

IMO the 70-200 is a more versatile lens and is incedible in low light conditions. The 100-400 does what it does very well, but is limited to shooting the long stuff. It all depends in what you're shooting.

Adding the 1.4 to the 70-200 take it to 280mm reach which equates to 448mm on a 1.6 sensor. The 100-400 translates to 640 with the 1.6 sensor. And yes, it makes a huge difference when you're shooting the long stuff.

Also be forewarned that there have been some quality issues with the 100-400 and the AF went out on mine. Sent it in for repairs and it's working just fine now and I don't plan on getting rid of it. Not after it assisted me in producing those photos.

Also read this recent thread over at Fred Miranda's site: http://www.fredmiranda​.com/forum/topic/61715

I agree with RFM's thoughts..

IF you need the 70-200 range,. with ythe Idea that occasionally the 1.4X or 2X t-con will be mounted,. then go for the 70-200mm.

The 70-200mm f/2.8 is fast and excellent in low light and offers that super narrow DOF when required.

But if it is 400mm is what you want,. then go straight for the 400mm!

T-cons are nice in a pinch,. but don't consider them as a replacement for the real deal...

That said,. T-cons are cheap too and make a lens flexible for the occasional use.. so if you get a 70-200mm you SHOULD get a 1.4X as well,..