Thanks Steffen and Brian, and not a reference to illogical number or other pure maths talk
. Having learnt photography on a Pentax K1000 and a Canon AE-1, I manged to grasp most of the concepts you mentioned. At the risk of cross-threading, can either of you shed some light (pun intended!) on my quesiton about 0.5x v f6.3 focal reducer question (Beginners Equipment) ?
