I didn't exactly agree with Mike's way of putting it, but neither do I see Roger's 'myth' of the grey card? What's the myth? I looked at Roger and Frances's site as referred to above and I come up with much the same as what Payasam alludes to succinctly: the use of some sort of uniform reflective surface, including one's hand, allows for a measure of the light falling on the subject instead of the light reflected from the subject. If one uses a grey card, what would one have to say about its use to fall into the supposed trap inspired by the 'myth' that Roger refers to? Is the myth just that 18% is not the reflectivity of the average scene? The statement that these cards have nothing to do with exposure seems to go a lot further than that. I have never used one by the way, but use my hand with the M6 regularly if I don't have my incident meter with me.