Thanks for your input. I don't do much 35mm these days but will be keeping the 63mm for the rare times I do. I compose and print from the whole of the negative to use as much of the film as possible. Going on from what you say does this also apply to 5x4. I currently use a 135mm EL Nikkor f5.6 which works wonderfully with 6x12. Should I be looking at between 180mm and 210mm for 5x4 negatives? My print size is usually 16 inches on the long side?