Originally posted by TER-OR The Q with -01 is compact. Not quite a pocket-sized except for your jacket pockets.
If you want to save space with a K-mount, just get the pancakes!
That said, I usually travel with the 18-135. If I know I'll do a lot of indoor work with people I'll have the 21mm.
I have the 40mm Ltd., 70mm Ltd. and the 21mm Ltd. and they are small lenses...pancake describes them very well. We just got back from a driving trip to Alberta and I took my K1, 28-105 and tucked my 40 and 70 in the bag. I used the 40 and 70 on my K1 for low light, no flash interior, portrait shots and even though they are ASP-C lenses...I just keep the K1 on Full Frame, not crop mode and I'm very pleased with their performance on the K1. I'm using F 2.4 on the 70 and F 2.8 on the 40 a lot, not always, but the results are fine...in my opinion. They seem to do the job. Could be my standards aren't as high as others...but I don't know.
I also use my 50 'normal' F 1.4, usually at around F 2 and my 50 Macro, usually around F 2.8 and these lenses also do the trick quite well. They're not 'pancakes' but they still take up little room in the bag, particularly when traveling in the car vs the plane. Bigger bag in the car.
Also stuff my 35 year old Minolta mini tripod ...copy of the old Leitz Table Top...in the back of my bag...quite stable little tripod. Just read pres589 post and reminded me of my TT tripod I carry around.