Justin, I hate to pick on you again, but your review is kind of all over the place. (Don't fly off the handle on me, hear me out.) I wanted to get more of a feel of how you specifically felt using the lens in specific situations...you know, take me there and let the reader feel like they are experiencing the lens. Instead, it's just awkward to read, and feels more like it's just you stating random facts about the lens, rather than your impression of it. Most important to me would be the autofocus performance and speed, as others who have bought this lens have discussed on here already, months ago. The IS performance would also interest me, and how it compares to the other lenses you mention like the 600mm f/4, or 400mm f/4 DO, or any of the other superteles, even the f/2.8's.No flying, I promise!
I probably missed it, but did you use anything other than a 7D with the lens? Just curious.
However, I have to admit the result you got of the floats and slide, with the 1.4 TC III attached, while also I assume having the internal 1.4x switched in...It looks nice and contrasty, and is very likely quite sharp. Nice job on that! That is full frame equivalent of an 18MP camera at what, 1254mm? That vastly beats the heck out of the results I got with a rented generation-1 500 f/4 with the 1.4x III attached to my 50D back in 2011 (and that was manual focus on a tripod with mirror lock in very bright Florida sun...since it refused to ever AF accurately no matter where I dialed the AFMA). Think about it...you're going through two teleconverters in series there...and the lens is a zoom to boot. Impressive stuff!
Sorry I didn't hit the mark on this one for you, I definitely tried to do better after all the valid criticism of my 300mm review. That said, I've never used a 600, 400 or any other tele other than the 300 so I'm currently unable to make such comparisons, the funny thing is as I move forward, in these "reviews" I have more experience than the last one.
I tested IS a bit on my kids (not a sports guy) and it was responsive and accurate, though it didn't feel as fast as the 300. I'm assuming some of this has to do with the sheer weight of glass it has to move. My general impression, and usage, was also a lot more than the 300, despite it being heavier and larger, the versatility of the zoom gave me confidence to take it out more and try different situations.
Most of my shots were with the 5DIII, I only did the 7D + 1.4 (yes with the internal 1.4 activated) as a fun test... how far can we take the "zoom" and yeah, not bad considering all the glass we're going through on a crop sensor. I don't know the copy variance of the 1.4 teleconverter III, but I have had incredible results on it with the 200-400 and my 70-200.
Hope that helps!
Sure thing, these comments were better than much of your review, haha, thank you! Interesting that you're saying the IS reacts slower than the 300 f/2.8 ii (perhaps you also meant the AF was slower?). Also interesting that you felt more confident taking it out because of the zoom versatility. I know exactly what you mean there! As for the 1.4x iii, I wasn't implying the problem was with it. The problem was the lens it was attached to, despite what fanboys of that lens seem to think (and despite LR testing it and saying nothing was wrong). Sure the camera's AF was less than fully capable, but that doesn't explain the problem when focused manually, with mirror lock. Bottom line, that particular sample of that lens, was simply not sharp. The TC just served to highlight the problem further. They delayed the shuttle launch anyway so I didn't even get to try to shoot what I went to shoot...I saw it on the pad from 13 miles away...the top half of it anyway. That wasn't even worth trying to shoot, either, especially into a 40 mph wind. So I left the camera and lens in the car and just tried to look with binoculars, haha.
Sorry, yeah, I meant AF... must be drinking again