[8540tomg]

Tough call.

The answer seems to change from month to month depending on my mood or interests. Regardless of my interest du jour one lens is always on my favourite list and that is my SMC Pentax K 200/2.5. Although it is over thirty year’s old it is still bright, sharp and contrasty and more importantly it just feels great on my K10 or any of my film cameras.

Tom G

[reeftool]

My favorite would be the DA 10-17 although it's not the lens I use most for the obvious reasons. My lens use tends to be seasonal with my telephoto's getting a lot of use spring-summer. Fall and winter is more landscape shots and indoors and my shorter lenses get more use. The fisheye is with me all the time and I look for opportunities to use it.

[farfisa]

Just a quick note-- a couple of people have mentioned the new 18-135 WR lens coming out. I notice your dad has a *istD, and this new lens has a built-in autofocus motor which wouldn't work with that camera. (it would work with your K-x though, if you got one! )

Other lenses that would seem like a good choice but wouldn't AF on the *istD would be the Pentax DA 17-70 (SDM motor) or some of the newer Sigma lenses with HSM autofocus.

So I'd second Ash's recommendation of the Tamron 17-50/2.8. Great to have the wide end there for landscapes, good range for indoors and a pretty wide aperture for portraits too. Also it's a reasonably priced lens.

[eddie1960]

Price is likely a concern as well, allthough i love all my manual lenses for various reasons, if i could only keep one lens from my arsenal it would be my Sigma 24-70 ex dg macro f2.8, not true macro but does a nice close focus, it's fast and reasonably sharp covers a good range (36-105 in 35mm terms) is compatible with film bodies and can be had for very reasonable prices ( I got mine for a little less than $400 from a local camera shops used dept
And to top it off if you use lightroom 3 there is a lens correction profile already there

[climit]

Mine best is for sure FA 50/1.4. It is very fast, has very good IQ, it's small. In a future FF camera with even higher resolution shall have the opportunity to show it's virtues even more.

[Eagle_Friends]

1. Ever since I sold my 40mm to try the 35mm Macro, I would say the 35mm Macro for the moment.

2. Easy, 16-45. Cheap and sharp. =]

[northcoastgreg]

(1) Although the 12-24 is my most used lens, my favorite is the DA* 300. Although the 12-24 is a great lens, it's not perfect. It's corner to corner sharpness at infinity is hardly ideal and it suffers from CA issues. No such issues with the DA *300. If you nail focus on it, it consistently delivers amazing results.

(2) The 16-45 delivers the best results at its price point.

[matsoberg]

I guess it´s the 31/1.8 as it´s the one that is mostly used. Great lens. I love it!

[dude163]

Super Multi Coated Takumar 50mm f1.4m42 mounted

[Biro]

As you can see, I don't lack for lenses but my three favorites now in my kit, depending on the situation, are: The DA 35mm f/2.4, the DA 12-24mm f/4 and - believe it or not - the DA 18-250mm f/3.5-6.3.

The DA 35 is surprisingly good for the price and may eventually get me back to using primes like I did in my film days.

When you need wide, you need wide and the DA 12-24 is one of the best, though not perfect (but what is?).

And that 18-250... I know a lens that long is a compromise but it's surprisingly good from 28-200mm and I can't tell you how many times I've taken it because I knew that, over the course of a shooting day, my needs would change drastically and too quickly to change lenses. There are tons of shots that I've gotten that I would not have if I had another lens on my K200D at the time. Do I wish it was faster at the long end? Sure. But I've shot a Major League Baseball game at night at 250mm, f/6.3 and ISO 800/1600, and gotten very good results.