The ones to watch are Ricoh lenses, which can have extra pins that jam on the K mount proper.

Then you haven't looked!

There's no shortage of "rules" and I would point you in the direction of any one of thousands of books on the subject. Know the rules first and then learn how to manipulate the knowledge to make images with originality and impact. But you do need to know the rules first.

Very few companies trade in these days and if they do the value will be very low.

I know you don't want to buy and sell but if you want best value that's the way to go. eBay offers one opportunity to sell, but also you can advertise here in the appropriate section.

Welcome Rivvy, does this mean you are from somewhere near Rivington or am I making the wrong guess with your username?

Hope you enjoy the site and the forum and we'll look forward to you joining in the fray!

If you do a forum search you will find several threads on this subject.

Personally I stick to the originals, which I have found for as little as £32, but many others buy a variety of alternatives.

The alternatives are generally a slightly lower specification than the Pentax ones.

That judhing is a lesson to us all. A very complete and well thought out set of comments, so full marks to the judge as well as to our Worthy Winner lenscape!

A good mirror lens will produce excellent results, albeit with the characteristic "doughnut" appearance of out of focus highlights.

Unfortunately there are lots of cheap and not very cheerful mirror lenses, usually 500mm. Many cost £99 when new and have dire optical qualities.

The Tamron is a good one, although I never really liked thew results. I preferred a conventional lens any day.

The Pentax mirror lenses are superb, but very rare and very expensive.

What SD cards is a matter of judgement, but personally I would use the best quality branded cards and restrict the size to no more than 1 or 2 GB.

The reasoning is that the best quality cards have less chance of failure (and are cheap enough these days anyway). How frustrating would it be to spend a days photography and then find that the card is corrupted and you can't access the images? Buy quality for this reason.

As for size, the bigger the card the larger the number of images that could potentially be lost at one time should the card fail, be lost or stolen. I use lots of cards from 256MB to 2GB in size, most of them being 512MB or 1GB. 512MB cards are quite useful in that the contents happily transfer to one CD for archiving purposes.

And another, this time Ripley Castle, from earlier today:
[IMG]http://i240.photobucket.com/albums/ff250/johnriley1uk/005-Ripley-Castle-1.jpg[/IMG]

Here's another image from the weekend trip, this time shot in Ripon Cathedral:
[IMG]http://i240.photobucket.com/albums/ff250/johnriley1uk/003-Ripon-Cathedral-1.jpg[/IMG]