Well, I am no expert and may be corrected but first I would use as low an iso as possible to keep noise to a minimum, though I have found no problems up to iso 400 and 800 is acceptable. But I have not used much higher iso's and would favour longer exposure or bigger aperture if the shot would take that. Higher iso's are (imo) for when you have no choice like when you must have a high enough shutter speed to avoid moton blur like at an indoor sporting event or something when you cannot use flash.

My experience of low light is in total darkness using flash or painting light and you can aford to experiment with your exposures.

However I guess to get inbetween your 15 and 20 seconds you could alter your aperture in the menu so that it is in third stops and then select say 20 seconds and close down 1 or 2 thirds to get your equivalent exposure.

You really need a remote for this kind of photography if you are using bulb setting because holding it down can induce some movement, which seems evident here to me.
Your exposures are not that long though that you need to use the B setting, you do not say which camera you have but at 17 seconds max you could set the shutter to your required time and use the 2 second timer to put the mirror up before the shutter opens therefore removing the likelihood of vibration.

From a photographic point of view to be honest im not really sure what you are trying to photograph unless its just a test shot. The pole in the foreground is out of focus and yet distracting,there is no point of interest in the photo.
You may have been better getting away from all the enclosed gardens and going out into the fields.
Keep it up though, this is only my inexperienced point of view.

Oh correction I see you have K20d, no problem with 2 second timer then

Im in Derby, happy to meet up.

Have to agree with the above posts. I bought my K20d with the 16-50, the first few shots i took were dissapointing and not really in focus. Had I read any of the problems at that time I may have sent it back. But it was just me using too slow shutter speeds for hand held shots. This is my most used lens and I have some lovely sharp images with it.

I was browsing in Dixons at the Airport a few days ago. There was a large Nikon Banner and a few Nikon cameras up for sale. No other brands at all.
However at the end of one isle there was a very good selection of Pentax binoculars, so whilst they may not stock Pentax cameras at least the brand is still about in the shops.

Very nice, reminds me I must go to Snowdonia very soon

Thank you all, I particularly enjoyed taking these

Just got back from my trip round some Spanish mining regions in Ameria and Murcia.
Here are a few pics, as you can see its quite a colourful area.

[IMG]http://i51.photobucket.com/albums/f396/Hannabella/Mazarron4.jpg[/IMG]

[IMG]http://i51.photobucket.com/albums/f396/Hannabella/Mazarron11.jpg[/IMG]


[IMG]http://i51.photobucket.com/albums/f396/Hannabella/Mazarron12.jpg[/IMG]


[IMG]http://i51.photobucket.com/albums/f396/Hannabella/Mazarron6.jpg[/IMG]


[IMG]http://i51.photobucket.com/albums/f396/Hannabella/Mazarron5.jpg[/IMG]


[IMG]http://i51.photobucket.com/albums/f396/Hannabella/Mazarron16.jpg[/IMG]

[IMG]http://i51.photobucket.com/albums/f396/Hannabella/Mazarron17.jpg[/IMG]

Sobriquet

I hope you don't mind me going off topic slightly. But I am interested in your trip to Afghanistan as I have been there myself a couple of times in the past, fortunately before the current climate.

I was there first in 1978 in the days it was still possible to travel overland all the way to India, just took the usual route, staying in Herat and Kabul.
The second time was about 6 years ago on a caving expedition we were staying in Baluchistan and had a few trips over the border.
Fantastic country and lovely people I would love to go back.

Are you there for work? And whereabouts? A few pictures would be nice when you can.

Thank you Peter, I have been to the pentax en/photo page many times but could find no link, couldn't even see it on the downloads page so than ks for the direct link I have it now.
My wife always says I never look properly.