If that particular element is cemented in place it may be something to do with the glue, can't say as I've ever seen fungus like that so I think it's safe to assume it's not.

I wouldn't worry too much about it, if your using this on a cropped sensor DSLR you wont be using the outer portion of the lens anyway.

You said:
"I think this proves what I said that if you move closer to an object, the image is the same if you use the correct lens. "

What you really mean is
"I think this proves what I said that if you move closer to an object, the object appears the same if you use the correct lens. "

The "image" will not be the same as all other elements in front or behind of the object your photographing will change in appearance with differing focal lengths, and as pointed out by John your subject in this case is pretty much 2 dimensional.

My 16-50 is on the fritz, bought in November 2015 and it refuses to focus, tried it on the istD and the screw drive works fine. I thought Pentax had resolved the issue with the SDM and my new copy should have been OK, obviously not

Fortunately I got it from SRS so have the 2 year warranty, just waiting to hear back from them as to whether I send it to them or direct to Johnsons.

I did try it on both K5 and K3II bodies and also gave it a good screwing on the istD but it's not come back to life.

I've absolutely no idea, Mrs Spider was working today so our Christmas starts tomorrow and the pressies are still under the tree

I doubt there's anything photographic though

Not that this forum is anything like this but........

How many online forum group members does it take to change a lightbulb?
1 to change the light bulb and to post that the light bulb has been changed.
14 to share similar experiences of changing light bulbs and how the light bulb could have been changed differently.
7 to caution about the dangers of changing light bulbs.
27 to point out spelling/grammar errors in posts about changing light bulbs.
53 to flame the spell checkers.
41 to correct spelling/grammar flames.
6 to argue over whether it's "lightbulb" or "light bulb"...another 6 to condemn those 6 as anal-retentive
2 industry professionals to inform the group that the proper term is "lamp".
15 know-it-alls who claim *they* were in the industry, and that "light bulb" is the industry standard.
109 to post that this group is not about light bulbs and to please take this discussion to a lightbulb group.
111 to defend the posting to this group saying that we all use light bulbs and therefore the posts *are* relevant to this group.
306 to debate which method of changing light bulbs is superior, where to buy the best light bulbs, what brand of light bulbs work best for this technique, and what brands are faulty.
27 to post URL's where one can see examples of different light bulbs.
14 to post that the URL's were posted incorrectly and then post the corrected URL's.
33 to link all posts to date, quote them in their entirety including all headers and signatures, and add "Me too".
12 to post to the group that they will no longer post because they cannot handle the light bulb controversy.
19 to quote the "Me too's" to say "Me three".
4 to suggest that posters request the light bulb FAQ.
16 to post "F".
44 to ask what is a "F".
4 to say "didn't we go through this already a short time ago?"
143 to say "do a Google search on light bulbs before posting questions about light bulbs".
1 forum lurker to respond to the original post 6 months from now and start it all over again....
😉 Merry Christmas 🎄

I've had several film bodies and lenses off Jessops in the past but after they stopped selling Pentax I looked elsewhere for my first DSLR after that it didn't take me long to find SRS so they now get 99% of my business.

Had Jessops continued to stock Pentax I would very likely have still bought there.

Fantastic news, you'll really enjoy the campervan

I'm not familiar with the 18-270 but I know from experience that the 16-50 has a nasty habit of locking up if it gets a knock while extended, a gentle wiggle (albiet with a bit of pressure) seems to ease the barrel back into place, the lens will then be OK until it's next knock.
This happened twice with my previous copy (until it hit York Stone Paving and went to camera heaven) and it's happened once with the replacement.

I haven't either, but then I spent so much last year they're probably letting me recover

Survivor and Positive are both good, but it doesn't harm to cross a few fingers and I'm quite sure there will be many of those.

Best wishes for you both.