Yes, I've heard that the Samyang 135 f2 performs well but I was hoping to avoid spending £430! I've been looking at Pentax 135 f2.5 secondhand but they seem to have mixed review for astro.

During lockdown I've been reacquainting myself with astrophotography using my K3II. I use the camera's built-in Astrotracer function, which is very good for shorter focal lengths and also a Skywatcher EQ3/2 tracking mount for my DA*300mm f4 lens that gives great results, even with the x1.4 converter. However, I've been disappointed with my DA*16-50 and my DFA100mm macro lenses that both show quite a lot of distortion of the stars (not star trails), i.e. bloated and non-round shapes, particularly away from the very centre of the frame. I wonder what other users have found?
Cheers

And another vote for the 16-85. Great image quality, useful zoom range and it handles very nicely too on my K3II.

Hi Andrew - suggest you take a look at this series on YouTube:
https://www.youtube.com/watch?v=IlTk4w0PS2g&list=PLpqDLK5jtPTTcsSF2oz7xBhofIoVVN...

Best
Darrel

I use Lightroom 6.14 and Elements 2020 with .PEF files with no trouble on my MacBook Pro running Catalina OS.

Merry Christmas John. I plan to get out and about in the Norfolk Broads to photograph some of the more out of the way windmills. Reckon I'll need my wellies!

Thanks - some good advice there. Think I'll go circular with some step-down adaptor rings.

I've been thinking of buying a ND filter (10 stop) for landscapes & seascapes. There's a lot of choice and great range in price, eg: £10 to over £100. Are the expensive ones really worth the cost?

Thanks Toni - good luck!