So i followed the advice of Me , and git a little a5 light thingy and some nd gel layered 3 together and laminated them as they were v thin did a strip test and settled on a 3 second flash in a dark bag , this exposure was 4 mins , quite pleased with the tonal range , onwards and upwards
These old ilford slides work perfectly with the light baffle for adjusting contrast too! You can usually get them pretty cheap on ebay.
That's great Ian, glad I was able to contribute.