Jordan - Nice review with some good representative pics! I'm getting more comfortable by the day having ordered this lens and X-T1. I was somewhat amused reading your comment that "the real issue is simply finding a way to put it in your bag". That's not exactly my issue transitioning from a Canon wildlife setup! I could sell you a monstrous bag cheap!
Dave
If you shoot a lot of wildlife, you'll be fine. If you're like me, or most mirrorless users, you'll have a small bag that fits 4-5 lenses....and will be dwarfed by this thing.
Well I've had it for a few days and it's big compared to most Fuji X lenses but's not that much bigger than the 50-140/2.8, it's mostly fatter and a bit longer. It can easily fit upright into my Lowepro Messenger 200 bag (in the same spot as my 50-140).
I don't like that the leg on the tripod collar is smaller than on the 50-140 since I use it to carry the lens while walking. It would also have been nice if it had Arca-Swiss compatible lip. ...and you can't switch it wont fit.
Here's the 100-400 mounted on my GS X-T1 if anyone was wondering about the size. It extends about 10cm at 400mm. The hood fits reverse and is in my opinion the better designed than the 50-140 hood. https://c2.staticflickr.com/2/1576/24589317594_3b5bbfacdf_o_d.jpg
Jman13 wrote:
Not an amazing shot or anything, but dang: 1/5 sec, handheld, at 400mm. This isn't consistent at this speed, but the fact it's possible at all is incredible.
Indeed. 1/5s is also not something to be relied on. I had maybe 2 or 3 shots that slow come out sharp, while around 50% at 1/15s (6 stops) and about 85% at 1/30s (5 stops)
The review is a good read and informaive like usual and very fine pictures Jordan.
I didn't buy the 1.4 extender since f/8 is rather slow for most subjects. It seems though that the lens is still quite sharp wide open with extender from what I've read. So maybe later I will add it to my bag for slowsubjects ...like mountains.
Here's the 100-400 mounted on my GS X-T1 if anyone was wondering about the size. It extends about 10cm at 400mm. The hood fits reverse and is in my opinion the better designed than the 50-140 hood. https://c2.staticflickr.com/2/1576/24589317594_3b5bbfacdf_o_d.jpg
I just placed my order and will test it extensively next week. I do quite a bit of birding (not so much BIF, however) mainly in various wetlands on both coasts, currently using the Nikon D810 and D750 with the 300/4PF (with the 1.4 and 1.7 TCs), 500/4 and the 200-500. I am most interested in determining how this lens will compare, with particular emphasis on sharpness and feather detail.
ariel777 wrote:
I just placed my order and will test it extensively next week. I do quite a bit of birding (not so much BIF, however) mainly in various wetlands on both coasts, currently using the Nikon D810 and D750 with the 300/4PF (with the 1.4 and 1.7 TCs), 500/4 and the 200-500. I am most interested in determining how this lens will compare, with particular emphasis on sharpness and feather detail.
Out for a walk this afternoon, took the 100-400. The Robin shot is with the 1.4x TC wide open at f8 560mm 1/200 and again handheld. First shot is the full frame and the second a crop of the same:
AF is pretty snappy as far as I am concerned. Blackbirds are pretty twitchy but grabbed this quickly with the smallest AF point size in single shot AF, same settings as the Robin shot except higher ISO:
I tried to go for some BIF shots... Now I have an admission to make, I thought I had updated the body to the 4.3 firmware but it was still on 4.0, oops. The big takeaway for me though, is that the viewfinder "blackout" makes BIF a complete nightmare! I persevere with the blackout with motorsports and I'll be trying aircraft, but for BIF I really struggled. I freely admit to not being great at BIF in the first place though!
This was about my best effort, and it's not that sharp really but that's likely due to my failings more than anything else. I'll be updating the firmware and trying again for sure.
When is your review for X Pro2 coming out? I'm specially interested in the comparison between Xpro2 and your beloved X-T1.
Jman13 wrote:
I tried it out on Friday and I have a review copy coming Tuesday. It's much lighter than it looks and the IS is incredible. I don't have great long lens handholding technique and was getting 5 stops easily. Very sharp even to the corners at 400mm.
I did a write up on this, the X-Pro 2 and X70 that I got to test.
I received my copy late yesterday and then did some BYB work as well as this AM. The lens is quite bulky with questionable balance on my XT-1 and cumbersome to say the least. Removing the "toy" foot makes HH a bit less cumbersome, and certainly not as convenient as my 300/4PF - D750 combination (which, among other things, and curiously, is less bulky, weighs less, balances considerably better, and is my package of choice for walk-about birding). Below are two BYB captures (with the XT-1), both of which required some work in LR to make them borderline acceptable.
ariel777 wrote:
I decided to stick with my Nikon package for birding as the Fuji 100-400 doesn't quite do it for me. However, I do love Fuji for everything else.
Focus speed, or more...could you be more specific, please?
I could stop at size, weight and balance.....the lens coupled with the X-T1 is imbalanced, difficult to hold etc. My birding equipment of choice is Nikon. I presently shoot with both the D810 and the D750. For HH, my preference is the D750 and the 300/4PF, naked or with the 1.4 and 1.7 TCs; the Nikon package is considerably less bulky, better balanced, weighs less and is considerably easier to hold, handle etc, with, IMO, considerably better IQ. I would add that I shoot Fuji regularly, love the brand, have approximately nine X lenses and have been looking forward to this lens for quite a while.
IMO, Fuji pushed the envelop to the extreme with this lens undermining some of the very reasons why many have transitioned...size, convenience and the like.
In fairness, however, I am not a fan of zooms, much preferring a fixed 1.4, 2.8 or 4.0 prime. fixed FL...tho I do have a number of zooms, including the recently released Nikon 200-500, which I use via a tripod. I should add that my interest in the 100-400 was to use HH, not with a tripod. If a tripod is appropriate, such as in a blind, my lens of choice is the 500/4, naked or with TCs.
Took this a couple weeks ago. I had just bought the lens two hours before using it. First Eagle shot with it. XT-1 and 100-400mm no TC. But got it in the package sale.
I'm getting more comfortable by the day having ordered this lens and X-T1. I was somewhat amused reading your comment that "the real issue is simply finding a way to put it in your bag". That's not exactly my issue transitioning from a Canon wildlife setup! 
I could sell you a monstrous bag cheap! 
