Call them all David and for a while yet they will be Doctors!

Black board is available from craft shops (they will cut it for you to the size required) and from Jessops in packs of 10, pre-cut.

In all cases I think it's just that you need to either shoot JPEG with the appropriately bright settings, to ensure as print-ready result as you can, or if being more subtle and shooting a natural JPEG or RAW then you need some basic adjustments in Photoshop. No escaping that really.

You do have some degree of backlight in the sky which will lead to under-exposure and that increases the drabness of the result, so adjustment is necessary at the taking stage as well. The exposure compensation should be set to +0.5 stop probably for those shots.

This is more about technique really, rather than equipment failure.

Hope that helps!

There are of course picture framers who will do you the job.

For DIY painless framing we mount our images on 20"x16" black board and buy the appropriate style of frame to put it in. The mounting on board is essential to ensure a flat picture. Cost of frames can be as little as a few pounds.

If and when the 645D makes it into the market, it will because Pentax have a very good idea how many they will sell, or maybe have pre-orders from existing high profile 645 users. They must think it will be their advantage, otherwise why bother?

Is there any common factor, such as images taken into the light being less good? I'm wondering whether you can pinpoint that the light coming from a particular direction causes internal reflections in the lens?

The filter could be to blame, especially if you don't use a lens hood. Modern lenses have lots of elements and use of a lens hood is a good idea.

If you could post examples of good and less good images then that might help to pin it down.

This is your Sigma? There are very often different versions of independent lenses, some Vivitar ones had four or more. The trouble is some are much better than others, so results can vary quite a bit.

There are even different versions of some Pentax lenses, especially the screw thread ones. After the bayonet lenses were introduced there were less variations, perhaps because lens design had reached a peak and there was less need for change.

An anteater could be arranged - what do you think guys and girls?

Very nice, I like that a lot. Wonderful sky and great tones on the stonework, very well done.

Peter, personally I use polarisers very rarely. I have both types, but find little need for them.

With wide angle lenses the vignetting they suffer often darkens the sky enough for me. If you remove reflections on water then you change the natural look into something else.

I tend to use polarisers when I want to photograph anything under the surface of water, or sometimes to reduce the glare from green leaves.

Hope that helps!