Nice sharp pictures. So are these with the Sigma zoom or the Pentax prime?

Wow these look great.
Buy two now before the price goes up. If you put the second one over your viewfinder facing the wrong way round you won't see any of the chromatic aberrations.If you keep it the same way round you'll get twice as much for hardly any more money- which is brilliant!!
One day I hope to own Nikon stuff so I won't even have to be there to take an award winning photo.

Vignetting shouldn't be too bad at all on APS-C sensors.

Don't forget the Voigtlander 20mm. It's f/3.5 and manual focus but it is small and highly rated by all accounts. Probably a bit more expensive than the pentax 20mm though.

Great sky. Feels like it's closing in on Paul.....

I like that a lot. The crescent moon in the opposite corner sets it off nicely...... nothing to bug me here

This may seem a bit odd but I quite like the first one , mainly because it bugs me slightly.
I admit I didn't think much of it when I first set eyes on it, and I wondered why you'd left the top of the wall in. But on revisiting it, the sky grabs you and you do need the wall for balance.
The bit that bugs me is that the wall slopes (minimally) down to the left but the perspective of the Abbey in the opposite direction emphasizes the effect and creates the effect of a much greater slant, (to me!) It's almost in the realm of an optical illusion. So yet again Paul,another image from you that makes you examine it more closely.
I don't think the sky needs a crop.... but if you do it would have to be just past the top of the clearly defined cloud above the abbey, about a quarter of the way down the frame.
If anything I'd be trying to slap an "orange filter" type of effect on the sky to darken the blue bits and add a bit more drama.

Not much to it. Though you probably don't need much storage. I can't imagine it's a high turnover item.

To me a shop like that says you're paying way over the odds for whatever it is you're buying.
But then, I'm a cynical old bar steward.....

Besides I'm going to win the M9 in the FFordes/AP lucky dip.....

Richard there's a Samsung 12-24 for sale on here at the moment for a good price. See Duncanm's post.

I know what you are saying Frogfish but basically JPEG is not and was not designed to be an editable format. To avoid confusing Charlotte even more,the suggestion of storing RAW+ ( raw and jpeg)is a very good one if you want to learn how to improve processing raw files.
The problem is that most cameras have more than one choice of JPEG quality setting. On the Highest setting you CAN do a reasonable ammount of tweaking of the picture after the event.But compared to raw that range of adjustment is very small. Raw files can allow you to rescue several stops of under or over exposure.
Similarly if you shoot in the lowest JPEG quality setting the picture starts to fall apart almost immediately if you try to change anything.
Also for best compatability with various software programmes DNG is a better bet as the sad truth is that the Pentax PNG format is not universally recognised, hence your strange colours.