The MkII and WR kit lenses are the better lenses, having resolution to match the larger sensors.

No idea how they all fare on a K10D, but on the K20D and later the difference is there.

No problem, nothing new under the sun, it's a great phrase.

I see a problem in that how can you make a complaint without actually knowing what the fault is? "It might be a scratch" isn't very strong and the shop who cleaned it could have scratched it themselves anyway. I think you need to know that it actually is a scratch and then decide whether or not it was part of the description and the overall deal.

Then there's the question of how long it is since the purchase and also was it a private or business seller.

You could send it to Pentax's approved repair house (JP Solutions), details are on www.pentax.co.uk and ask for a warranty repair. It isn't 2 years since the K-5 appeared so iot could well be under warranty. At least they will tell you definitively what the fault is.

I think naming the lens would be useful Algi, otherwise we don't know what we're comparing against.

Without getting back to the same discussion as before, which, by the way, may well be an effect of spherical aberration due to de-centreing, the MTF results are what they are. Very often, lenses gain reputations but the lab results may or may not show something extraordinary.

At the end of the day lenses are for making images and MTF testing only shows a technical result. The 43mm has that extra "something" which gives the images a certain quality, a warmth of drawing and reproduction.

By comparison, the SMC Pentax-FA 50mm f1.4 I find generally "bland", the f1.7 is much better, but it may have very impressive MTF scores. I don't know about that, I haven't tested it in that way.

What I do know is that I would reach for the 43mm before the 50mm f1.4 without a doubt.

Of course this is what makes a lens test and interpretation of it so difficult, we can't ignore either the technical aspects or the creative emotional ones. It makes it very difficult for those not familiar with the technicalities.

At one time there was a fad for camera club members having their lenses tested and I recall Kevin MacDonnell recounting the tale of how Mr 96 lines per mm was so proud, sending Mr 80 lines per mm away, crushed.....

If we take the 43mm and use it to make images we should be very happy with it but, as Algi says, technically speaking the edges do lag markedly behind the centre.

Lovely shots, another area of photography I have yet to explore.

Just to pick up on the primes issue, modern primes will be better than zooms in most cases, but the ones referred to by Algi are designed for film and not really up to the rigors of the DSLR.

Some older lenses can be good, but many are not.

The distance to the subjects at the edge of the frame might be a factor. If they fall outside the depth of field then sharpness would suffer. A simple way to find out is to pin up a newspaper page on a wall, make sure the camera is central and parallel to the subject and make test exposures at various apertures. How the newsprint is reproduced will tell a lot about how sharp a lens is.

On a tripod using the 2 second delayed action.

It may be exactly so, but in general worth checking that the softness isn't due to either camera shake or subject movement. Trees and plants sway in the breeze....

Forum etiquette on this is that the judge does not get involved in this thread after the entries start coming in - it can influence the judge, and in this case the judge may be influencing future (but not existing) entries by providing ideas.

For that reason I'm taking the comment out, to ensure a level playing field for all entrants.