Julian, Sorry , I've no idea. Perhaps it's just a mistake - like their website still publishing the MTF curve for the old EF 100 f2.8 macro non-USM as though it's correct for the current lens which has more elements and a different construction. I find it hard to believe that there's no resulting difference in MTF.
Malcolm Milton Keynes, UK ----- Original Message ----- From: Julian Loke <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, November 10, 2002 1:08 PM Subject: Re: EOS Seeking macro information > > The 4.3" (10.9cm) quoted* for working distance for the older EF 100 f2.8 macro > > non-USM agrees closely with the 11cm (lens front to subject) I measured when I > > had mine. > > (* in the link http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=000rXL > > Hi Malcolm, > > That is very strange. Do you have any explanation for why Canon uses 15cm? > > Is it because the front element of the EF 100mm f/2.8 macro is recessed? > > Or because many Canon lenses can focus closer than the published minimum > object distance (and often further than infinity)? > > Cheers > Julian Loke * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
