Fraser,
Cheers for highlighting these for me, I bought some a while back and they were far too small for my use so sent them back to Amazon. Bought the 38 & 50mm lenses from Winternight69,
Looking forward to doing some tinkering. I've got some kind of thermal telescope in mind, so if anything pops to mind let me know. You are significantly more experienced in all this than I am,
Cheers again!
Niall