today [Better title would be 5D MkII problens with manual focus and shutter]

<p>I did a shoot today and ran into unexpected problems with the 5D2. With the 85mm L lens, it refused to focus manually, then the shutter refused to fire. I had to get out my Nikon D700 to get the shot. What up dudes? Does this thing quit in difficult situations? The focus was a very wide range, it was set at f16, and it did not know where to focus, so I tried manual, which would not work. A while later the Canon worked and I replaced the Nikon with it. Any comments or suggestions?</p>

<p>Sounds like a lens/body connection issue, just clean the contacts with an eraser and all, hopefully, should be fine. Similar thing used to happen to my 70-200 and 1D. The 85L needs power from the camera to focus even in manual as the AF is a daft fly by wire arrangement.</p>

<p>Yep it always quits in difficult situations. Canon equipment never works right when you need it.</p>

<p>Why Craig, just last week I wanted to photograph my parachute jump, except that my chute didn't open. I took photos of my fall with my 1DsMkIII and wanted to take the very last one when I was just a few feet from hitting the ground. It worked perfectly.</p>

<p>Could you post the pictures please Stephen?</p>

<p>Please use sensible and descriptive titles for posts. "Today" is NOT a suitable title for this thread.</p>

<p>I will change it this time but in future posts with cryptic titles may be rejected. This applies to everyone of course.</p>

<p>I'm not sure how any lens can "refuse to focus manually." Just move the little switch on the lens to the MF position and turn the ring until the image is in focus. Press the shutter release, and everything should work fine. If you're using Live View zoom in to a reasonable magnification so you can see detail. (If your eyes are like mine you might need some reading glasses to see the LCD screen clearly.)</p>

<p>When in doubt, try autofocus. Make sure that little switch is back on AF and point the center AF sensor at something with a definite edge or an area with a change in contrast.</p>

<p>Oh, and there's only one plane of focus regardless of whether the aperture is set to f/2, f/16, or f/128. But you knew that already. Setting the aperture to f/16 doesn't help you to acquire focus on that plane.</p>

<p>If you put the lens in "MF" and the camera is not in an automatic mode....I think it should fire independently of the focussed subject, you can have everything blurry if your choice is such...am I wrong ?</p>

<p>Dan</p>

<p>The 85 1.2 has a fly by wire focus motor, the focus ring is not connected to the focus group physically, it is effectively just a switch, if there is no power then you can't focus even in MF (my first post had a typo and should have read MF not AF).</p>

<p>All of the early tele AF lenses did this, not until the IS teles came in did Canon drop it. It is a pain because if you own an early tele and the focus motor goes the lens is dead, Canon don't have the parts for them anymore so it can't be fixed, you can't even use it as a manual focus lens. I believe the 85 is the only lens that still has this arrangement.</p>

<p>Laurent,</p>

<p>You are right unless the camera is getting conflicting reports from the lens contacts. Mine just used to lock up, it wouldn't focus, take a picture, anything. A really good clean of the contacts sorted out all my problems though.</p>

<p>Ugh! That sounds like a peculiar design. Thanks for the explanation. I'm glad that I don't own that particular lens.</p>