There may be sample variation in any lens batch, but we should expect that all the Pentax lenses will deliver good images. Our kit lenses (we have had five of these so far) have all been very consistent as it happens and have all produced pleasing results. They have been best at about f11, which is pretty much what I would expect from low cost but well made zooms.

Poorer zoom lenses will continue to improve all the way to minimum aperture, but this is as the errors in assembly get covered up by increased depth of focus at the sensor. In other words, they never reach acceptable standards.

Really good lenses should peak at just one or two stops down, and the comparitive test on CSC lenses in the new AP (out tomorrow) actually shows this very well. Sadly no Pentax lenses in that test though.

A theoretically perfect lens should peak at wide open aperture, thereafter being diffraction limited, but this never happens as there's no perfection in lens making.

Then I'd personally suggest you go for the K-5 and this is the time for it. Soon the moment will, I suspect, have gone and there will be a new higher priced version.

There are members here who take incredible pictures of airshows, using older Pentax cameras than the K-5, so I doubt that you will have a problem.

I would consider more whether or not the faster frame rate of the K-5 would be an advantage. It's clearly up for replacement itself, so the price at the moment is excellent. It is more durable with its magnesium alloy body, so if you use your cameras professionally it might be an advantage.

However, I think both will be perfectly viable options.

You have one of the two variations of the Model I, manufactured between 1962-1967. The optical configuration is the same.

You should also find that your version has a half stop click stop between f16 and f22.

I thught this was interesting and a taster for some great possibilities:

http://www.facebook.com/l.php?u=http%3A%2F%2Fwww.adorama.com%2Falc%2F0013716%2Fa...

Agreed, after all it is meant to be fun.

This feature was introduced on the K-01. Not having a 50mm f1.2 lens I can't comment on how it would affect the focusing problems, but every mention of this beast of a lens always makes me wistfully think I'd quite like one.

Unfortunately I can't find a convincing end to the sentence: "Sue, I really will have to get a 50mm f1.2 lens because....."

The requirement to take the image during the 2 weeks of the competition is the only reason I rarely enter.

I tend to be very busy photography-wise and there's not always the opportunity to divert into something else. I think I should try harder.

Although rumours do seem to leak out, not by much, the system as regards keeping things under wraps does seem fairly efficient. In these internet days quite surprising really.

Interesting, K10D.

When you say plastic mounts are profit orientated, you don't I assume therefore think that metal mounts are not? Presumably we are here talking about cutting costs. Given that we know the cost of a metal mount 50mm f1.4 and that this is similar across all marques (the full versions, not the cut price ones), then keeping the optical quality the same must mean that costs can only be reduced elsewhere. A plastic mount and plastic body construction is one cost reduction possibility, and after all Pentax users have been asking for some lower priced prime lenses.

The 35mm f2.4 is a superb lens optically and hopefully the new lens will be too. I don't want Pentax to make ultra-cheap lenses that are actually tacky. The 35mm may be plastic, but it's impressively well made.