Lens for birds in flight and other?

As with every purchase I tend to internet research to death, although on this on I'm stuck for people who have actually used the gear.
To put this into context first: I need a relatively affordable, transportable lens that can cover birds in flight, general nature photography and potentially a little sport shooting. By relatively affordable it needs to be under R20 000 all told, that is just over US$2500. Also bearing in mind that in South Africa we pay something like 15-20% more than in the US or the UK on import duties (where a Sigma 300 2.8 is $2600 at BH Photo, it is $3200 in South Africa).
By transportable I mean that it needs to be able to fit into a backpack with body, several other small lenses and a laptop for extensive airline travel as I work across Africa.
Lastly I need a range that extends to 400mm.

The options I've looked at so far:
Nikkor 70-200 2.8 VR with dedicated x2 TC
Sigma 70-200 2.8 VR with dedicated x2 TC
Sigma 100-300 f4 HSM with dedicated x1.4 TC
Nikkor 80-400 VR
Sigma 80-400 VR

At the moment I'm leaning towards the Sigma 100-300 with 1.4TC. I like the fact that if I need a 300 f4 I have it. I also think that the IQ will be better at 400 with a 1.4 TC than any of the 70-200's with a x2 TC.

Please, any thoughts or advice would be most appreciative. Has anyone had the opportunity to test these combinations. Any other experiences on other lenses that I perhaps haven't included in this list? (before you even mention it, yes I would love the Nikkor 200-400 f4 VR, but at a selling price of over $10 000 in SA it's beyond what I can afford)

Thanks in advance

I am not familiar with any of your suggested combinations. The only advice I can give you is that for flight shots it gets more difficult with a x2 tc or x1.4tc attached. You didn't mention what body you have. I use a 1.4x when I need one as my focus is faster than with a 2.

Of the lenses you listed, the Nikkor 70-200 is the choice if you are going to use it with a TC. It focuses fast, has prime lens IQ and integrates well with Kenko/Tamron and Nikkor TCs. Either the Nikkor or the Sigma 80-400 would be a last choice - exposures would have to be too long with a TC, and neither are noted for their focusing speed, even without a TC. Not sure how the 100-300 would do, but there again, with a 1.4x TC you will be at 5.6 max aperture.

Birds in flight require either a practiced hand and total familiarity with the lens, a good focusing screen, and a good bit of right place at the right time thrown in for good measure, or fast pro-level gear - at the minimum, a D200 or 300 body, and pro AF-S lenses. Some of the Sigma EX lenses focus fairly quickly, but I do not have much experience with them. Many people swear by the Sigma 70-200, but there seems to be some agreement that while the Sigma is an excellent lens in all respects, it is a bit behind the Nikkor in terms of IQ or build quality.

VR is of no use to you if you are trying to catch action. In fact, it might work against you.

I just looked at a used Sigma 50-500 EX DG and found it to offer reasonable IQ, fast focusing, and decent performance wide open. I had it on an old 11 lb Bogen tripod with an Arca Swiss Z1 all locked down, so there was little in terms of vibration to mess up the image. Which brings me to an imporant point. Many user reviews report a loss of sharpness at 500 mm with this lens - I suspect that they are using the lens either handheld or on a cheesy tripod, in which case it is the setup rather than the lens itself that is contributing to IQ degradation. Something to consider.

Emil what camera are you going to use with the lens you want to buy.
Also you can drop the 80-400 vr nikon as it is far to slow.
You have the 120-300 2.8 of sigma which I have heard excellent reviews on it.Also works well with tc1.4.
I have the 300 f2.8 and use only a tc 1.4 also I have the 50-500 of sigma which gives me great results.
The Nikon 70-200 VR f2.8 is an excellent lens and using the TC with it should give you very good results.
VASBYT and good luck

I agree with a previous writer. If you ever wanted to use a TC then I would to with the 70/200vr Nikon. I rented this lens just before going to AK to shoot bears and eagles and it worked very well. I thought that I was going to be presented with many low light situations so my own 80/400vr was going to cut it since it is too slow in low light.
You may want to rent your favorite choice to try it out. I found that to be very resonable.

Don Gorczynski

Arthur Morris swears by the Canon 400/5.6L for birds in flight. It's relatively inexpensive, sharper than any zoom (especially one used with a TC), and light enough to hand hold as long as you want.

http://www.birdsasart.com/

There must be a 400mm Nikon prime that you could check out, or Nikon-mount equivalents by Sigma, Tamron, or Tokina.

Based on my experience, I wouldn`t recommend the Sigma 100-300mm f/4 for flight shots. The autofocus just doesn`t seem to be able to keep up. Nearly all the flight shots of large, slow-moving birds such as gulls I have taken are just slightly out-of-focus. (All taken with Sigma 500mm f/4.5 are sharp.) I imagine using a teleconverter would only make matters worse. That`s my experience, anyway, for what it`s worth.

I have the Sigma 100-300 f4 and the sigma 1.4x I think it works very well
though I have not had anythign else in this range to compare it to.

Jim clark

Thanks for all the advice. To add to my previous post, I shoot with a D200. I'm interested to hear that the Nikkor 70-200 shoots well with TCs, so this might be the better route to take in that case. The Sigma, which I've played with on a Canon 5D, was great on it's own but lost contrast dramatically at the long end with a x2 TC. Reckon I'll go and find somewhere to play with a Nikkor 70-200

Thanks again

p.s. when funds allow it I will get a dedicated tele such as a 300 2.8. I currently use Nikkor 400 3.5, but as its a manual focus it gets a little tricky for birds in flight.

Emil, I have the D200 and the 300/2.8 and 70-200VR. I love them both. I'm not an expert bird shooter, though. But for what you describe that you want to be able to do with the one lens you choose, and that you'll be using the tc, I'd sure agree with recommending the 70-200/2.8 VR. Incidentally, I use both these lenses with a tripod set up with a Wimberley Sidekick. It improves the number of well focused shots. Perhaps this won't be an issue for a guy with much stronger arms and shoulders when it comes to handholding. Good luck with your pick.

Thanks Catherine. To update on my decisions...while looking into the 70-200 I came a across a seller who was putting up his whole kit for sale for what could be considered a paltry sum. along with the gear came the older 80-200 f2.8 (the two ring version). This was all for less than a quarter the price of the 70-200. So although it's not AFS and I have yet to discover its qualitites with a TC, I'm loving it. It's sharp, fast focusing on the D200 (remember I'm used to MF) and focuses that bit closer than its newer AFS cousin, thereby producing some really beautiful portraits. Hopefully I'll get a chance to post some pics soon