Hi guys - another question from me. Last week I purchased a 5 year old 503CW. It has a circular magnifier and a standard matte focusing screen (the one with the simple cross in the middle (no split image)). I met my friend yesterday who had a much older 500 (I think) which had a squarer magnifier and a split image grid style focusing screen. When I used my magnifier it was basically impossible to focus. His magnifier was a lot clearer and the split image made a difference. My question to the forum is: Which focusing screen and magnifier combination is generally regarded as the most accurate/easy to use? Many thanks in advance for your help! Cheers. Charlie.