I always found the corners of the kit lens a bit of an issue at 18mm although - 35mm is it's 'sweet spot'. It is very good for general photography but I wouldn't go as far as to say it's an 'excellent' lens as some people insist it is. A more realistic description is 'good enough for most purposes if stopped down a bit'.

I have the Tamron 17-50mm which is a sharpness demon, but I kind of miss my 16-45mm: I loved the focal length and images seemed to have a certain richness and clarity despite being marginally less sharp under close examination. Hated the zoom extension on it though!

Matt I think the 40mm is too close to the 35. You could sell one depending on which you prefer though- in which case i'd get it 2nd hand. But the 35mm is such a nice lens, i'd keep it and get the 21mm or 70mm if you must have a pancake. The 70mm would be my preference, having mulled over the reviews and tried the 21.

Most useful - probably the Sigma 10-20mm. But I love using my little collection of primes so these all get regular outings - especially the 35mm f2.4.

Least used is probably the F35-70mm, which gets passed over for more flexible zooms or faster primes. And my Tamron 90mm macro hardly gets taken out - I pick up my 135mm f3.5 in preference when I need a telephoto... must be a size thing.

Ah, then that's even better... the extension tube was an annoyance to be honest so I never took it out with me

That was a very fair price. I got one with the PKA adaptor and 1:1 extension tube for under £75, all boxed etc... keep your eyes peeled and a bargain may crop up again. Anything under £100 and you'll have no difficulty recovering your costs if you decide to sell it. I kind of wish I hadn't sold mine as I loved the compact size (without the extension tube).

It's a fully functional AF 'budget telephoto' lens...

Can't open link Jaqui, what lens is it? This chart helps with lens compatibility, but of course all Pentax mount (PK or PKA lenses) are usable to some degree. http://www.mosphotos.com/PentaxLensCompatibility.html

It is if they want to buy the appropriate module for their Ricoh-Pentax GRX, to go alongside the K-mount module for their favourite K-mount lenses!

The DA15mm does exert a certain pull on my wallet, although I don't think it outperforms my Sigma 10-20mm enough and it would be a luxury which exceeds my lowly skills as a photographer ;P I have tried the 21mm and decided the focal length wasn't quite for me, not quite wide enough to feel properly wide angle, not quite as concise a FOV as my (much cheaper) 24mm MF prime. I also struggled a bit with the pancake design. It had wonderful contrast and colour to it though, and if wide angle isn't your thing, go for it!

The pre-dawn lake shot ticks all the right boxes, but I really like the sunlight shafting through trees in the following few shots. The second to last one like a nuclear test, but I like it!