The only things that should be in a Classifieds thread are the offer to sell and questions from people interested in buying.

Everything else just clutters things up.

If the lens was purchased through a Pentax Pro Dealer and has 2 years warranty then contact them to arrange a free repair or replacement, presuming it is less than 2 years old.

Failing that, consider taking advice from Consumer Direct if in the UK and exploring the six years you have to seek a repair/replacement on the grounds that a lens should last longer than the time you have had it.

As a last resort, paying for a repair is another option.

As regards reliability, there were early reports of SDM problems with this lens, although there were also many more people who had no problems. I wouldn't let it put me off buying one.

Most zooms vignette to some degree, but in most images it's not really noticeable. It depends on how good the lens coverage is and more compact designs will vignette more.

The 18-55mm does vignette a little more than the 16-45mm, depending on focal length as well, but both are very acceptable for general use.

In the days of darkroom printing we were encouraged to darken the corners of a print slightly to concentrate the eye more on the subject matter, so what may be a "defect" in modern lenses is perhaps a good thing after all.

Some of the best photographers have always taken advantage of what many see as faults in equipment.

The Pentax K was very early, something like 1957 from memory.

The K series was the first bayonet series of 1975, so Pentax have always happily re-used nomenclature.

Now we have the K series DSLRs....

According to The Ultimate Screw Mount Guide, the K stands for King...the King of cameras.

One option is to start again with a new account.

The second is to make a Report to IT and they will sort out your current account. See the bottom of this page and click Report Problem.

You only need to know that f8 or any other aperture is the same on every lens, regardless of the size of lens elements it needs to achieve that.

Zoom lenses are often variable aperture because the focal length chjanges, but the size of the glass doesn't. A 100mm lens has to be a lot bigger than a 50mm lens to achieve an f2 aperture, for example.

I would try logging out, restarting your computer and starting all over again to log in. Just in case.

However, I can assure you when I click on your user name I get an active account.

Check your spam folder to make sure that the activation e-mail has got through. If you use Outlook Express or Windows mail then also check any online version of your e-mail. That will have a spam folder all of its own that might have the required e-mail there.

Your account is active and in good order.

Can we stop the personal comments please.

If we discuss the issues instead of having the personal sniping it will all go along much better.

They are from very different eras, but there is no lack of "bite" or contrast in the SMC Pentax 24mm f2.8 lens.

My first suspicion is that the exposure may be off and the 24mm images are actually over-exposed and a little washed out. This could be caused by a lazy lens diaphragm not closing quickly enough, or by the exposure errors that may occur when using older lenses on the DSLRs.