in B2.79b highlights max out at V=1 - how do we use that for our clamp values?

the clamp values seem to work the same way as in 2.73, but unless i am mistaken, the max specular is now 1.0 in B2.79b. is there some multiplier that we should use to help us judge the clamp value? is the multiplier simply 5?

thanks, julian darley