The unicorn exists!

[DavidEccleston]

I am tempted. I'm just not sure what to sell to make it happen.

For those wanting a 70-300mm debate... going from 300 to 400mm doesn't seem like much, but it is. I mean, it sounds bigger yes, but not enough that it would make much of a difference, would it?. But it's 33% more range (+100/300), which translates to 77% more pixels on target (1.33 x 1.33). That's a fair chunk of extra detail, and/or newly usable shots.

I would use this when I'm focal length limited, ie: stuck outside the agility ring at the opposite side from the dog. Especially a small dog. At this distance (95-105 ft), at 300mm, framing is 7-8 feet wide, which isn't ideal for a 1 foot long Yorkie. The 400mm would drop that down to 5.25-6 feet, and the DOF would drop from 7', to 4', and the background blurring away fairly quickly.

I'd actually done most of this math already, and was considering using the 70-300L + second body w/ 400 f/5.6. I didn't think the Tamron 150-600mm IQ would be good enough, or the focusing fast enough, nor accurate enough. The new 100-400 makes things easier, as it gives me a known level of IQ, build quality, IS, and focus speed.

If they had pushed past 400 that would have been icing on the cake, but I think this lens will make a lot of people very happy.

[Kayaker72]

If they had pushed past 400 that would have been icing on the cake, but I think this lens will make a lot of people very happy.

Exactly.

It really does look like a great lens, perhaps one of the better ones. I was going over it again this morning and there seems to be improvement across the board. Better contrast, bokeh (using the theory that the closer the meridional and sagittal lines are, the better the bokeh), and very even corner to corner sharpness. Combine that with 4-stop IS, assumed better AF, etc. This looks like a great lens.

The only reason I haven't preordered this, as I am looking for something in the telephoto/super telephoto range, is that with the 1.4TC, the 30 mm line @ 560 mm f/8 drops to ~85%. At f/11, it is astounding (~96%). So, somewhere between f/8 and f/11 even with the 1.4 TC this lens goes from good to a very good option even at 560 mm. EDIT: I spent a little time looking at other lenses with MTF ~85%. This actually includes most of the Big Whites with 2x TC.

That may be enough for me. I am fence sitting. A few good reviews may push me over the edge.

Well, I guess there is also the cost factor as I would also need to buy a 1.4xTC (I own the 2x).