[Smeggypants]

bigma 50-500...it'll get you near or far, has very decent iq at any range, and only requires a small forklift for operation.

best regards!

lol

[dadipentak]

The premise is nightmarish but the answer is pretty easy: the Tamron 18-250mm was my first lens and it would be the last. No other lens (except the DA version ;~) does so many things so well.

[RioRico]

The premise is nightmarish but the answer is pretty easy: the Tamron 18-250mm was my first lens and it would be the last. No other lens (except the DA version ;~) does so many things so well.

Oh, that's too easy!

(It's my basic lens too. My other ~215 lenses are all specialty tools.)

[daniel deus]

fa35 f2, small and light and great optics. a lovely combo with the k5

[Pixley]

As alway's, the DA* 50-135mm.

This - although it is a tad on the heavy side when using it for any length of time. The other would be the Sigma 50 1.4. I really would like to team it with a FA 77mm but one thing at a time!

[willywalker]

77mm Limited. No question.

I have the 21m Limited and the 31mm Limited. It is almost impossible for me to take the 77mm off the camera!

[Lemmy]

A 10-330mm f1.8 weather proofed zoom about the size of the 12-24 zoom. This lens would have the sharpness of the prime lenses at all zoom lengths and be able to focus to 1:1 at all settings.

Price, not more than £250. As far as I can see, you didn't specify that it had to exist

[Lance Tsai]

I will keep DA* 50-135 for my K5 and keep DA 15 for my K-M

[Limpy]

FA 43mm ..... Perfection!

[robgo2]

My favorite lens is the FA43, but if I had to live with a single lens, it would be either the DA*16-50 or the FA31. The choice would come down to versatility vs. IQ in a broadly useful single focal length. It's a tough choice that I'm glad that I don't have to make. In either case, I would cheat, by holding onto the FA43.

Rob

[jlstrawman]

One more + for FA 31mm f/1.8 Ltd. Second most favorite is the FA43mm.

[rparmar]

I think I'll make it five votes for the FA 77 Limited. I don't care about versatility. I simply want godlike imaging. (Not to mention I screw an acromat on the front and get a macro lens to boot!)

[panoguy]

(Urg - not a fan of the site redesign - hard to post....)

I do adore my FA 43mm, but for a one-lens-kit I'd have to go with the DA 50-135mm. Never lets me down, sharp as a tack, and renders colors and OOF almost as well as a Limited.

[EdMaximus]

For the past year, I have been working with just two lenses (DA 35macro and FA 77mm). I'm in a financial situation where I have to forgo one of them. It should be a no brainer for me to just keep the FA 77mm since the majority of my work is done with it but I think I might just sell both of them and acquire the DA* 55mm or the FA 43mm. I could have add the DA* 50-135mm in that list but only if I didn't hate shooting with Zoom. I'm leaning more toward the DA* 55mm right now.

[RioRico]

On the original question -- someone may have already responded thus, I haven't reviewed all the answers (no coffee yet this morning!) but:

If we can have only one lens, why bother owning an interchangeable-lens camera?

What we're getting here are answers to, What's My Favorite Lens? If I didn't want to change lenses, I'd stick to Dad's old Minolta Autocord with the Chiyoko Rokkor 75/3.5. Or maybe get a G10 or whatever.

(Ah, the coffee's ready. Well, it's depresso -- decaf espresso -- but maybe it'll help me think more clearly and elevate my mood. The Autocord needs a CLA anyway.)