[Outis]

So, I've been thinking about getting a pancake lens-- it would be really nice to to throw my K-3 in my purse and just take it everywhere with me.*

I'm not sure whether I would be better off with the 21mm or the 40mm, though. I tend more towards landscapes and buildings, and less towards people and flowers. It would still be nice to have versatility, though. The lens I use the most is the 31mm, which handles everything with grace. I also have the 15mm already, which is small enough for the purse treatment. It's terrible for portraits, though, unless everyone wants a giant nose

Any thoughts? Do I want the 21mm, the 40mm, or something else entirely?

*Notice how this thought ended up at "I need another lens," not "I need a bigger purse"? This is the way things should be, right? Right? My own flimsy justification is that if you have a purse that's too big, some places will make you surrender it, and then you don't have the camera, so that's no good...

[robjmitchell]

43ltd comes to mind 21ltd sounds more like you although the 31ltd does pair up nicely with the DA*55.
HD 21ltd is slightly better than SMC version but second hand SMC save you some money.

[johnmflores]

21 will be more versatile/suitable for your needs. You can also take off the lens hood and use a standard 49mm lens cap to save some space.

[tvdtvdtvd]

For landscapes and architecture, I'd say get the DA21. But ask yourself this: when using the 31mm on those subjects, do you find
it to be too short or too long? The answer to that question should tell you which lens to get.

[mtux]

Based on your explanation I'd say get the 21, it's more versatile for walk around. fantastic for landscapes, superb for environmental portraits.

[mattb123]

I carry the 15 and 40 as a compact kit a lot and they make a great combo. So I'll buck the trend and say get the 40. Great lens and so compact.

[NZ_Ross]

I carry the 15 and 40 as a compact kit a lot and they make a great combo. So I'll buck the trend and say get the 40. Great lens and so compact.

I have a 15, 21, 40 and 70 Limited primes.

I have found that once I brought the 15 I haven't used the 21 that much. It is a very nice small lens, but I just find the 15 better for landscapes.

Further to what Matt has posted - the 15, 40 and 70 make a very good small 3 prime kit. You wouldn't loose much with a 21, 40, 70 kit either, which would be even smaller

[jimr-pdx]

The 40xs is another option, if you prefer crêpes to pancakes you might even get to buy a smaller purse too, by going that way!

[simon6z]

It will be the da21 then since less people and more to building

[chrisfer]

You already have the 15mm and 31mm, for a trio take a 70mm, or better if you can, the 77mm.

If you want use just go with one lens, the 21mm is then a very good choice.

[Rondec]

If you want something small that is "better for portraits," then I would go with the DA 40 or, the DA 70. The 40 is tiny, has nice image quality at f2.8. The 70 is just a little bigger and probably is better for head-shot portaits, but would probably be a little long to be a general "walk-around" lens.

[Sandy Hancock]

I prefer the DA21 to the DA15, so I guess I'm against the trend here. It is smaller, sharper, a bit faster, and a more accessible and versatile focal length. The 15 is still unique though, and I have no intention of parting with it.

I had the DA40, but after I got hold of a second-hand FA43 I could not see any reason to have both, and the latter is a far more interesting lens.

The DA70 would be a better alternative if you want a great compact portrait option, but again it has a big sister in the FA77, which for me was impossible to resist once experienced.

[savoche]

Hmm...
- For landscapes and builings, I'd say the DA21. I like the FA28 even more, but it is slightly bigger and not as nicely built (and available second hand only, of course).
- For a small "FA31 substitute" I'd say the DA40. Or FA28

I see you already have the FA77, too - which means you really should get the FA43

What makes for a good walkaround lens very much depends on what focal length you prefer. Personally I find the DA21 a bit too wide for general use outdoors but perfect when indoors. For landscapes/cityscapes I mostly prefer either wider (usually the DA15) or longer (FA28 or even FA43). That said, some of my (IMO) best landscapes were shot with the DA55-300.

[Apapukas]

I don't think anybody can ever go wrong with the 21Ltd.

It has just so many uses, so versatile, so small, but delivers constant results

[Sandy Hancock]

I see you already have the FA77, too - which means you really should get the FA43

Doh! I didn't check his profile.