Do they do this? I wasn't aware of that! Perhaps I've been imagining it all along, but I perceive that it prefers a slightly lower shutter speed when I have IS on. Must be my mind playing tricks on me...neuroanatomist said:Interesting that Canon changed their recommendation. I wonder if they have/will alter the firmware for newer cameras accordingly, to use faster shutter speeds in Av than 1/FL for FF and 1/(1.6xFL) for APS-C. I've always found it interesting that Canon ignores IS when selecting a shutter speed in Av.Mt Spokane Photography said:The out of date rule, 1/shutter speed was updated by Canon to suggest that 1 / 2 X shutter speed be used for modern high MP sensors and non-IS lenses. For a 24 mp APS-C or 5DS, I'd use 1 / 3 X shutter speed when possible.