I just thought that I would share this with you so that you know for future reference. Yesterday I started my preparation work on high magnification photography using a PB6 (2 X PB-6Ds) - PK11a-PK12-PK13-BR2A and a 24mm lens in reverse mode. Made up my measuring chart to calculate the Reproduction Ratios obtained with different set ups and started. Could not believe results. Massive R:Rs that blew my mind. Something's up I though, this just cannot be true. So went to bed. Woke up with a jump at 3.00am shouting ' YOU ARE A RAVING IDIOT'. Frightened the cat and Pam out of their skins and the hamster poo'd itself. I realised that I had worked in Square Area Measurement instead of Linear Measurement, hence the ludicrous results. What a wally. I have now put it down to senility and an over indulgence of The NIKON CAFE!! Best wishes. Bob F.