Ok these are what I am buying

[Simon Spiers]

For my wildlife photography I have decided some time ago to but the 100-400 f4.0-5.6 USM L .
This seems a good all round telephoto for the 20D.
Then I am gonna buy a 400 f5.6 USM L for those tripod shots.
Would anyone dispute my choice?
I am having to work at the weekends to finance this addiction so reasurance is great.
Thanks

[CorruptedPhotographer]

So as I understand it, you are buying 2 lenses? the Ef 100-400 and the EF 400?

I would look into getting the EF 300 f/4 L instead of the EF 400 f/5.6 L. because if you attach a 1.4x extender, you will be @ 560mm @ f/8 which is very slow (trust me I have a f/6.3 500mm) and you lose AF. On the other hand, if you get the EF 300mm f/4 L and add the 1.4x ex you will achieve 420mm @ f/5.6L and still maintain AF and possibly 5% to none picture quality degradation.

I wont dispute the EF 100-400, since it is a damn good lens. But if you want a little extra reach, there is the Sigma 50-500 :)

[condyk]

I'd just get the 100-400mm IS L ... though for my own use I'm getting a 300mm IS L f4 and TCon as it combines prime quality and some essential flexibility from 300-420mm, though not the flexibility of the 100-400mm IS L of course.

[CorruptedPhotographer]

soon to be following condyk's footsteps. My sigma 50-500 is nice and all, but rather slow @ 500mm. Well slow when the sun starts setting.

[lordjim]

I would look into getting the EF 300 f/4 L instead of the EF 400 f/5.6 L because if you attach a 1.4x extender, you will be @ 560mm @ f/6.3 which is rather slow

If he loses a complete F Stop with a 1.4 TC on the EF400, he will be at 560mm F8 (not F6.3) which is even worst.

[CorruptedPhotographer]

lordjim, you are right. Where did I get the f/6.3 from though? I thought it went 4 -> 5.6 -> 6.3 -> 8

[lordjim]

lordjim, you are right. Where did I get the f/6.3 from though? I thought it went 4 -> 5.6 -> 6.3 -> 8

This is confusing because some cameras allow you to determine your aperture by half a stop (F2.8 to F3.5 or F5.6 to F6.3 or F8 to F9.5) [even a third of stop when you use EC]. In addition some lenses minimum aperture falls between two full stops (such as the Canon 10-22 F3.5 or the Sigma 500mm F6.3 you referred to). In fact, it goes F2.8 ->F4 -> F5.6 -> F8 -> F11 etc., therefore loosing a full stop at F5.6, leaves you at F8 and, as you said, leaves you without AF with the XT or 20D because they can not AF with lens slower than F5.6 (some pros cameras are still able to AF at F8 though). Good revision for me too. Thank you. ;)

Simon: It seems to me that buying both a 100-400 and 400 prime may not be the most efficient choice unless you already cover all your needs in terms of focal lengths and can easily afford both. You will certainly gain in image quality with the prime at 400mm but at a very high cost. The solution suggested by CorruptedPhotgrapher the 300 F4 + TC is probably one of the best compromise image quality/versatility.

On the other hand, the 100-400 remains probably one the best long telephoto zoom with IS out there. I find mine extremely sharp up to 380mm after that it looses some sharpness at all apertures. I find it even sharper than my 70-200 F4 between 100mm and 200mm.

If I were you, I would first determine whether I need a zoom or a prime and then go from there.

You can even rent lenses to see which one best fits your needs. Most vendors out there can even give you a credit for the renting cost, if you decide to buy a lens after you rented it.

[CyberDyneSystems]

The key is you are getting the 100-400mm first.. with that in hand you will be better able to judge your needs for the next purchase..

My guess is you may start to think about something faster...

[Simon Spiers]

I see where your coming from on this matter. My idea was buy the 400 prime after the zoom to give me the realy sharp shots i long for. However it would be better for me if I try the zoom first before buying the prime.
CYBERDYNE when you say safer ,do you mean less telephoto and more appature?
Thanks everyone

[grego]

I see where your coming from on this matter. My idea was buy the 400 prime after the zoom to give me the realy sharp shots i long for. However it would be better for me if I try the zoom first before buying the prime.
CYBERDYNE when you say safer ,do you mean less telephoto and more appature?
Thanks everyone

Yeah, he means a faster lens like 400 f/2.8 or 400 f/4, possibly.

[CorruptedPhotographer]

LordJim, yes I did think it had something to do with half and third increment stops.


Simon, if you already know what focal lengths you want. Then buy a prime unless zooming is a neccessity. If you dont know what focal lengths you need, go for the EF 100-400 and see which lengths you use the most.