Canon 100/400 mm lens

This is an excellent choice in lenses its sharp even at 400 . I thought ide regret it when I heard tamron is coming out with a 150/600 but if its anything like the sigma 150/500 I doubt its sharp at 500 let alone 600. Get the canon and don't look back . Want more length get a 1.4 extender . I am real happy I got it. Flying eagles tack sharp at 200 yards at 400mm.

While I agree that the 100-400 is a fine lens, I would think it wise to wait for lens reviews of the tamron rather than make wild assumptions about the performance of an unreleased lens.  The 50-500 os performs quite well, for instance, so there are examples of quality 3rd party supertelephoto zooms.  I have used both the 50-500 and 100-400 (which I own), so I have done the comparison myself.

Additionally if you add a 1.4x teleconverter your camera will not AF with phase detection, leaving you only live view unless you have a 1dx or 5d3, and even then you only get center AF.

I've owned the 100-400, the 400 5.6, and the sigma 135-400. The 400 5.6 wins hands down for colour, af speed, contrast and sharpness IF all you want is 400mm. The 100-400 is a very flexible lens (that's why Canon paired it with the 24-105 as a kit offering when the original 5D was introduced), it's not perfect though, dust gets in with the push pull design and it's not the sharpest when combined with the x1.4 converter. The little sigma is light weight and plastic but does the job for those on a budget. There are of course others that I have not owned.

There's certainly room for a third party to introduce a competitive lens. I gave up trying to do birding with these slow lenses, it became obvious to me that 5.6 at 400mm was too soft, and f8 and sharp was far too slow for small birds in typical UK lighting conditions. The conclusion I reached was I needed another couple of thousand pounds at least for a faster lens  to attempt reliable captures.

I'm very pleased with my 100-400L, purchased it in 2007. I'm happy with the results of the Kenko 1.4 when shooting the moon or sun. I use the lens primarily for wildlife while camping in Northern Maine.

I like the push pull zoom. Mine has no dust.

hellgap wrote:

This is an excellent choice in lenses its sharp even at 400 . I thought ide regret it when I heard tamron is coming out with a 150/600 but if its anything like the sigma 150/500 I doubt its sharp at 500 let alone 600. Get the canon and don't look back . Want more length get a 1.4 extender . I am real happy I got it. Flying eagles tack sharp at 200 yards at 400mm.

Fortunately it is nothing like the Sigma 150-500.  Very much like your Canon 100-400 with an extra 200 mm.  Reviews of the Tamron from people who have used it have been very positive.   Now that it is in circulation, the pictures being produced by those who have it, can be seen to be as good as those taken  by the canon 100-400.   Mine is on order.

amosesh wrote:

Awesome…Thats what I was waiting to hear…Eagles are available to pose for me at a distance, and I'm really looking forward to capturing the moments…I'm saving up my credits for a purchase thru amazon….Thank You for your feedback...

I own a 100-400L, and it is indeed a very nice lens. But if I were buying now, I'd wait for reviews of the new Tamron 150-600 before making a decision. If the Tamron is reasonably sharp (as early reviews tend to indicate it is), and if its AF is reasonably fast and accurate (which the early reviews are less clear on), then the Tamron--with its additional 200mm of reach--may well be the way to go.