I suppose that's true. Just odd though. If the lens isn't closing the aperture enough it will, of course, over expose so it could be a mechanical problem. I mainly got it to use when the weather's poor to avoid lens changing and it's WR to boot so shouldn't suffer problems used in isolation.
The other lenses I was using to compare the exposures were the FA50mm 1.4 prime and Sigma 24-60mm zoom, both of which had identical exposures judged by the flashing red over exposure warning. Indeed the f stop, speed and ISO indicated were the same for all three lenses, it was just the exposures that were inconsistent.
With the new Pentax zoom most of the sky ended up flashing red, not so with the older prime and zoom which rendered the sky quite well. A further test at around 100mm comparing it to the DFA100mm macro produced a similar result. If this is the effect of the HD coating rather than a mechanical problem I'll avoid HD versions in future, but suspect it is a problem that could be dialled out in a service.
If I had the K-1 with only this 28-105 I wouldn't be too happy with the combination. The only other time I've experienced anything like this with the K-1 is with a Tamron Adaptall lens with the 'A' mount. Perhaps that's the common link, Tamron?
I'll try some more comparisons before I decide whether its a keeper or not.

I bought one too but my initial impression is it over exposes slightly and tends to lead to burnt out highlights. Other lenses at the same focal length i compared it too didn't over expose the same shots. If I dial in a bit of underexposure its OK but I don't think I should have to do that by default with what is still a pricey lens. I'm debating whether to return it.

Yes, normally have some in the garden but not this year.

Thanks. Yes it was great fun and free to all to see. I agree it would be great to join in, though my engineering skills wouldn't achieve anything more than a plank with four pram wheels! I suppose that's a start.

Not seen an admiral this year at all. That one from yesterday has been around again today (given there's only one I presume its the same one.) It must be feeling quite lonely.

Thanks. Actually I think I did see it hovering before it landed so that is quite probable. It's not one of our usual ones though, quite a bit smaller. At least that's narrowed down the search.

It's certainly similar, but not quite the same.
Try this search for the plain tiger butterfly:
https://www.google.co.uk/search?q=plain+tiger+butterfly&client=firefox-b&biw=101...

Anyhow, at least some small tortoiseshells are around, but I agree not as many as usual.
That butterfly I photographed was amazingly around on the same flower head for several more hours after I took that!

Think I sussed the weevil. I believe it is a grain or wheat weevil. Given there is a field of wheat adjoining the garden that seems highly possible.
The 'wasp' may actually be a fly but still not sure.

I find it hard to believe the Mail could get that so wrong. The photo agency credited is Alamo; looking on that site they have plenty of photos of the real thing so I can't see that there's any excuse. Yes, one wonders if anything they publish can be trusted after that.

One's a tiny weevil (much smaller than a vine weevil - about 1/8 inch long) and the other some type of what I believe to be a small wasp. Can anyone be more precise in identification please? Thanks for looking.
K-1 with Pentax FA 50mm macro.