> > > Chip Louie wrote: > > > > What body you mount the lenses on can make a big difference in > perceived AF > > speed. The EOS 1v is really fast the EOS 1n is only very fast, but the > > particular lens models seem to vary in AF speed with different > bodies for > > some reason. > > > > For example, an EF 28-105USM mounted on an EOS 1n seems no > faster than when > > mounted on the EOS 5QD and EOS 50E bodies. When I mounted the > EF 300 2.8L > > on the EOS 50E the AF speed was much slower than on the EOS 1n. > Maybe the > > power supply makes a difference as I always use a power booster > E1 with good > > NiCad packs on the EOS 1n bodies I use. > > Although I think Canons official word is, that the power supply won't > influence focusing speed, my personal impression is different. Maybe they > are right and it's just the fact that with the booster some > things (mirror, > focusing, film transport) work simultaneously while without the booster > all is done sequentially?! Anyway, I have to agree with Chip that certain > lenses (mostly the "big" ones) seem to benefit more from a fast > camera like > the 1N or 1V than others. The 80-200 f/2.8L is most definitely > one of these. > That may well have something to do with the central sensor of the > 1N, which > works as a cross sensor only with f/2.8 or faster lenses. > > Thomas Bantel
Hi Thomas, The requirement of a f/2.8 aperture to activate the central cross sensors in the EOS 1n/1nRS are part of the reason I wound up owning only lenses f/2.8 or faster! If you are using an EOS body that requires a f/2.8 or faster aperture to activate the cross sensor and don't use f/2.8 or faster lenses you are wasting the capabilities of the fast AF system of the body. I had been using a pair of EOS 5QD bodies and made the switch to the EOS 1n a few years ago. I was VERY disappointed to find that for some reason that with my own lenses on the EOS 1n's I bought, AF speed was not as fast as it was on the rented and borrowed EOS 1n's I had become used to while shooting sports. I didn't realize how much faster the EOS 1n AF is when using EF 300 2.8L and EF 400 2.8L lenses which I also begged, borrowed and rented! The AF speed of the EOS 1n is definitely dependant on using the faster lenses and fresh power packs. This fact and the MUCH better images I saw on my chromes forced me to sell off all of my slower lenses and buy fast ones. This is how and why I have come to have my collection of "L" lenses. Regards, Chip Louie * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
