I picked up a job lot of lenses that included an EF 35-70 3.5-4.5, an early one with a metal mount. When I tried it on my 400D it was OK with flash but gave Error 99 and stayed stopped down as soon as I tried natural light bright enough to need stopping down. Iris won't now open. Is this an inherent incompatibility with these early lenses, like early Sigma for Canon, so they'll only work on 35mm bodies, or have I just been unlucky and got a faulty lens?
Update - seems to be working properly on a 1000F 35mm body. Tried looking this up and nobody admits to any incompatibility with any genuine Canon EF lens on a DSLR. Tried it again on the 400D and it seems to be OK, so maybe it just needed the contacts cleaning more than I originally tried. Fingers crossed!
