Thanks for sharing. I have the current version and love it for its useablity. Thaught i would end up selling mine after getting the bigger 2.8 bother, but just cannot seem to part from it. New upgrade would be welcome news.
Does anyone know how many years it typically takes after Canon files a patent for a new lens for them to announce it as a new product? Or does it vary too wildly to admit of any "typical"?
What new glitches will it have for the $2,300 (IMO) price…it’s a bit less in weight (the old one ain’t bad), and it works better in warm weather (wasn’t aware that was a problem with the current model)…but the main improvement that I can see would be to mount my old one on a newer body. Will the new one still have the clunky IS noise?
Andrew Welsh wrote:
I'm with dgenx24... where's the 400/5.6 IS?
Adding a TC doesn't give the same optical quality, nor AF responsiveness, as just the lens by itself has.
I guess... but the new lenses seem to be much better with the TCs. Maybe Canon wants to release the long expected 100-400 first, showcase its optical improvements over the previous version and 400 f/5.6 and drive as many potential buyers to it instead.
But first they need to release the 200-400... C'mon Canon! It's already been in use at the Olympics...
Ernie Aubert wrote:
Does anyone know how many years it typically takes after Canon files a patent for a new lens for them to announce it as a new product? Or does it vary too wildly to admit of any "typical"?
Most patented lens designs never make it into a final product. The time between patent release and
final product (if any) can vary between a couple of months and a couple of years.
Fr3d wrote:
Most patented lens designs never make it into a final product. The time between patent release and
final product (if any) can vary between a couple of months and a couple of years.
Just to support Fr3d's remarks, having worked in the tech industry I can say there is no mathematical correlation between filing and time to product arrival. Most never make it and I've seen an occasion or two where the filing barely beat product introduction. Overall, my impression is that Canon is rarely in a hurry
Andrew Welsh wrote:
I'm with dgenx24... where's the 400/5.6 IS?
Adding a TC doesn't give the same optical quality, nor AF responsiveness, as just the lens by itself has.
If the new TCs were developed to accommodate a new 300 f/4, the optical quality hit may be small. The AF would be slower for the 300 +1.4x than for the 300 without it but that's not the relevant comparison. The 300 II +1.4x III may be just as fast as the 400 f/5.6 I
Of course, they'll never go this route ... but it would be a killer combination of manageable size/weight, reach, speed and versatility.
Makes more sense to me than the 400/4.0 D.O.
? 
enough so I would sell my 100-400 to get it