The campanula is lovely. I like the way all the "detail" is piled up on the top right with the "nothing" underneath almost seeming to support the plant.

Wow. That's a performer.

What's not to like here? Lovely composition.

The basic bellows that simply extends the distance between lens and camera is a magnification device. You can tweak the focus with it but you will change the size of the object too. Now put camera, lens and bellows onto a separate focus rail. You choose the magnification with the top rail/bellows extension; then you move the entire sheebang back and forth, using the bottom rail, to focus. Say you were doing a Coker style 30 shot series for a focus stacking job. If you relied on the single bellows rail to move the focus along the subject it would get bigger and bigger and bigger (or smaller, depending which way you go). You need them all the same for this caper so the two rail system is better as you only shift the focal plane, rather than change the object size.
The Pentax ones are very nice but the traditional BPM products are just as good, so there's a lot of choice out there.

Wonderful. Thanks for sharing them.

I was trying to capture some chaser images a day or so back - it's jolly difficult even to get acceptable shots, so these are really superb.

As always with macro, you just learn more and more - and with your macro, more still. Thank you.

Talk about feeling a right twerp? The collar I bought arrived - Chinese and quite excellent - but I'd ordered a 68mm!! I think I'm losing it sometimes!
Anyone got a need for a very good 68mm tripod collar?

I have always had excellent results from the Pentax M and A series 100mm macro The FA and F versions are equally good if you are desperate for AF. There is simply no need to buy expensive new ones. If you drop back slightly to 90mm you can have the universally acclaimed Tamron offering for £100 - 150.

Thank you. Something new to learn about.