Advice on a fast prime

[mfunnell]

I'm contemplating a lens to fit a perceived hole in my lens line-up. What I'm after is a fast (and fast-focusing) medium telephoto prime lens. There are 3 1/2 candidates, to my mind: the 85/1.8, the 100/2.8 macro and the 135/2L (all, I know, very different lenses at very different prices). The half-candidate is the 200/2.8L. All are said to be sharp and fast-focusing (and, of course all are as fast as their apetures state).

I'll set out (with illustration) my reasoning so far, in hope of correction if I'm going off-beam.

The gap I see is in low-ish light nature type shots (often but not always) birds near dawn and dusk where, almost by definition, the light ain't so bright. The near typical kind of shot would be this:
http://www.mikefunnell.com/sulphur_crested-in-flight-11-web.jpg
It was taken early-ish in the morning, and to keep the shutter speed up I had to compromise exposure and do my best to correct in post-processing. It's the almost-but-not-quite type of shot I'd like to get with a faster lens. (Yes, I know I could fix some of this with a different camera body - but that's already in the budget.)

That, to my mind, suggests the 85/1.8 - the more light the better, after all. And, in that shot, I wouldn't have cropped the tips of his wings (but that's not really the point). I've read many posts about the abilities of this lens for indoor sports which, while no interest of mine, suggests to me that the lens would be up to the task.

But then I look at shots like this (taken with the over-maligned 75-300IS that's now with my father):
http://www.mikefunnell.com/rainbow-lorikeet-feeding-1-web.jpg
While this was later in the morning I'd missed earlier opportunities because between light and subject movement I couldn't get shutter speeds high enough. And I doubt I could have got close enough at an 85mm focal length, even with crop factor, without spooking the bird. That makes the 135 look attractive in every way except price.

And price is a factor, especially if I'm not going to blow the budget over that new camera body. The other factor is that I also kind've like shots like this:
http://www.mikefunnell.com/bee_and_blue_flower-1-web.jpg
which I found awfully difficult to get with my existing equipment. That suggests to me that a focal length compromise (to 100mm) with added macro capability and with (considerable) cost saving mightn't be such a bad idea. But, still, f2.8 is slower than 1.8 or 2. Is adding macro capability going to compromise my initial purpose?

My tentative conclusion is something like: the 85 gives the best low-light capability but may be too short and may even be too slow-focusing (only in comparison to the other two lenses, judging by the reviews). The 100 is reported to be both very fast-focusing and very sharp, even in non-macro applications, and does deliver it's added bonus on the macro front. The 135 probably meets my original requirements best, but is by far the most expensive - costing (here in Oz, at least) twice what the 100/2.8 does.

So, even though I'm compromising my original low-light requirement, I'm thinking that the 100 will probably give me the best return on cost, even though at f2.8 it probably can't be considered really fast.

Am I fooling myself? Would I be better off bighting the bullet and getting the 135? Or going for the widest apeture and saving myself some money (the 85 is the cheapest here)? Or is the 200/2.8 something I just haven't thought enough about?

Advice please, if you care to.

...Mike

P.S. I know a 70-200/2.8 might be an option but really can't be in the budget.

[GyRob]

if the 85mm will give you the image size ( the view of a 136mm on your 300d ) you want of the first pic i would say get it as is fast and very sharp too also it works great with a closeup filter so would give you closeup shots too if you want closer then an extenion tube,just my thoughts.
Rob.

[Choderboy]

Have you considered the 100 f2.
Fast and very good IQ

(although it is not a "close focuser" - minimum focus distance not very impressive)

[Lester Wareham]

The 100mm f2.8 Macro was the first lens I got after the kit lens, I knew from my FD days I wanted macro lens bad.

The rest of the system is designed around that.
The 135 f2L and 85 1.8 are very good lenses, but for the moment there is too much overlap with the 100mm.

You have to ask yourself how important macro is to you. The macro version will be bigger and heavier than the non-macro f2 or the 85 1.8.

[vjack]

I will be very interested to read all the replies you receive. Although I don't have any of the lenses you mentioned (yet), your rationale seems tight. The only thing I wonder about is whether the lenses you mentioned are going to give you enough range for most birds.

[jjonsalt]

135L f/2.0 and 1.4x TC.

[mfunnell]

The only thing I wonder about is whether the lenses you mentioned are going to give you enough range for most birds. The 100-400 works fine for that when the light's good. The f2.8 70-200s would probably be "best" (though not as fast as the 85 or 135). They're budget busters, though. The 135 is attractive (esp since I could add the 1.4 tcon later) but also expensive. I suspect that this range of focal lengths (85-135) is more practical in low light. It's the range I've actually used when pushing the 100-400 too far (1st photo above was at 100mm).

Thanks, all, for the replies so far. I'm still thinking.

...Mike

[liza]

I own the 85, the 100, and the 200. All three have great IQ, but I think you might be most pleased with the 200 and a set of extension tubes. You can use it for birds and for macro shots.

[CyberDyneSystems]

Keep in mind the 100 macro is also the slowest lens to focus,. not just aperture... of the lenses you mention. Very much so.

[mfunnell]

Keep in mind the 100 macro is also the slowest lens to focus,. not just aperture... of the lenses you mention. Very much so.Hadn't realised that. It's very important to know, so thanks.

...Mike

[Lester Wareham]

Hadn't realised that. It's very important to know, so thanks.

...Mike

The internal focus USM version is not particularly slow under normal conditions, only if you let it hunt the full focus range in low light. There is a switch to limit the distance range of AF.

But its is true, a faster ap means faster focus. You need to decide how close you need to get. You could always add a small tube to get a little closer with a non-macro lens, although this will probably cause some light loss and slow down AF.

To be honest if you are after birds you should be looking at the 300/f4 IS or 400/f5.6.

[Choderboy]

Hadn't realised that. It's very important to know, so thanks.

...Mike

That's why I suggested the 100 f2

[mfunnell]

That's why I suggested the 100 f2Sorry for not noting that. It has registered. I haven't looked at that lens at all - but now I know I should. Against my will (and bank balance) I'm thinking that the 135 is looking good. However, I might be able to get the 100/2 and 200/2.8 for similar cost. Even more to think on. Damn.

...Mike

[Lester Wareham]

Sorry for not noting that. It has registered. I haven't looked at that lens at all - but now I know I should. Against my will (and bank balance) I'm thinking that the 135 is looking good. However, I might be able to get the 100/2 and 200/2.8 for similar cost. Even more to think on. Damn.

...Mike

The 200/2.8 is a very sharp lens and light and compact too (I love it).
The 135/2 has rep as being Canon's sharpest prime many say.

The 100/2 or 100/2.8 Macro is a hard call. From the MTF data the f2 has better edge sharpness (full frame) and the f2.8 better centre sharpness. This is I guess what you would expect for a general vs macro lens.

I can't spot if you are crop or full frame. If crop the 2.8 should give more detail over all the frame (based on the MTF).

[liza]

I have the 100, also. It's very sharp at 2.8 and focuses relatively quickly. I use it and the 85 for basketball. The 100 f/2 and the 200 f/2.8 would be a great combination.