The Helios 44k is a rare beast indeed, but if you're after a common or garden 44 (M42 mount) then try your local charity shops and car boot sales. We appear to have a local bylaw that states every charity shop must carry at least 3 Helios 44's (each with a broken Zenit attached to the back) at any given time. Car boot sales will usually yield 5 or 6 of them at an average price of £2 each.

Doubt you'll get quite so lucky on a Jupiter 9 but they're worth hunting down - lovely lenses.

As a rule of thumb prime lenses are fairly straightforward to dismantle and service whereas zooms are a nightmare. That's not to say it isn't possible, just that your chances of getting everything back together are Kate Moss slim.

If it's a fairly cheap lens (and from what you say I guess that it is) then you have little to lose by giving it a go. Take lots of photos as you take it apart so that you have a reference when it comes to the hard bit of putting it back together.

As for grease, I use lithium grease which is perfect for lens helicoids as it's resistant to large variations of temperature and won't run - use it fairly sparingly and clean the old dry grease off first with a stiff brush (an old toothbrush with a drop of Fairy Liquid works a treat). You can get tubes of lithium grease from places like Halfords for around £1-2 and there's enough in a single tube to re-grease hundreds of lenses.

Good luck

The more money you pay for a camera (or car, or golf clubs, or anything really) the more you feel the need to justify your purchase as loudly and as publicly as possible - so it seems to me anyway.

Both Nikon and Leica enjoy a reputation for high quality cameras and lenses, so it seems reasonable to suppose that there are a large number of folk out there who buy those brands simply because they think it will make them a better photographer.

Of course we know it doesn't work like that, but I can see why those people need to keep cheering on the team. After all, if word got out that owning a Leica didn't automatically make you the new HCB the bottom would fall out of the used market and they'd be even further out of pocket...

Keeping the K-mount would defeat the purpose of making a mirrorless camera. Existing lenses would still require the same distance to the sensor as they do now in order to retain infinity focus.

What you'd end up with is a body exactly the same size as the existing DSLR's but with a big hole where the mirror used to sit - a completely pointless exercise unfortunately.

If Pentax do introduce a new EVIL camera then it will have to have a new lens mount (or maybe a Micro4/3's one - it is open source after all and it would solve the problem of having to launch a full range of lenses at the start). Of course we would hope that a K adapter would be available too...

Nice collection! I think the K is the most handsome model there, one I wouldn't mind for myself.

Very nice!

I never did buy the 31 as its "stand in" (the DA35) has done such an impeccable job. Maybe one day when I'm rich...

The 12-24 is an excellent lens - I'm a big fan of primes (especially the nice compact Pentax Limiteds of course) but I make an exception for the DA12-24. It's probably the best zoom lens I've ever come across so I forgive it its relative chunkiness compared to my other lenses.

As for the gap between 40mm and 300mm how about the D-FA 100mm Macro? It's almost a half-way house (40mm + 150% = 100mm, 100mm + 150% = 250mm so near as dammit ), it's very light, takes the same 49mm filters as the Limiteds (and many more Pentax lenses), not much bigger physically than the 18-55 kit lens, gives 1:1 macro without additional accessories, makes a fantastic portrait / mid-telephoto lens and is good value for money. That's what I'd plug the gap with anyway...

I don't know what's more suprising - that he got such a bargain or that you didn't beat him to it Clarky

From my experience selling cameras and lenses together won't get you any more money than the higher priced item on its own. For example, take a camera worth £50 and a lens worth £100, bundle them together and you'll get... about £100.

With that in mind, plus the fact you're not going to use it, plus it's not likely to ever be a rare collectible - sell it now is my advice.

Or do like I do and use it as a wet-weather sacrificial lens. Although it's not technically waterproof I've used mine in quite heavy rain with no ill-effects. If it does break then you've not lost much but you've saved your 16-45 from taking any damage - better than a UV filter for protection!

Very nice! So which one's favourite?