5d mk2 focus issue

<p>I did purchase a 5d mk2 (used) a couple of weeks ago and I sometime have issue with focus.<br>

When I half press to focus it focus normally most of the time. <br>

The issue is that when the lens do not focus properly, It will not restart focussing after I released the shutter and half press to retry focus. The only way the lens will start focussing is to change shooting mode (ex: ''A'' to ''M'', etc) or or do ''OFF-ON''.</p>

<p>It does the same issue with both 35/2 and 100/2 I own.</p>

<p>I did not have this issue with the 5d mk1.</p>

<p>Does anybody have the same issue with the 5D mk2?</p>

<p> </p>

<p>Some questions to help clarify your issues...<br>

Does it give you a focus confirmation? (the red light on the active focus point(s)) It should when you achieve focus, but not when you don't. <br>

Are you using all the focus points, or simply the center point?<br>

Are you shooting AI Servo, One shot, or AI Focus?<br>

If you dramatically reframe after having failed to focus, does it make a difference?</p>

<p>Marcus,<br /> just to clarify:<br /> Most of the time it works normally - red light on the active focus point.<br /> But when it don't achieve the focus, there are no red light (which is normal) but as explained it sometime (not systematically) it blocks and there is no way to retry focus.<br>

It does the same issue with all the focus points or only one point.<br>

I shoot One shot 90% of the time and 10% AI servo.<br>

If I dramatically reframe it don't make a difference.<br>

The issue is hard to reproduce but it does happened 1-2% of the time.<br>

If I shoot intensively during in a day it will happened a couple of times.</p>

<p>I've shot with a 5D2 for over 3 years and have not experienced your AF problem. However, the few times my cameras act up--my cellphone and computer too--resetting the PRAM cures it 99% of the time. The other 1% of the time it is toast and needs service. Reset the PRAM by removing the mains and backup batteries and letting the camera sit for a spell. This action flushes out all your special settings and forces the code to reload fresh.</p>

<p>Check that C.Fn-III-1 is set to 0 not 1.</p>

<p>That helps clarify it for me. C.Fn-III-1 set to 1 (vs. the default of 0) shouldn't result in that problem, turning on AF again should always activate the AF again - though that may contribute to an intermittent fault in the event of a firmware glitch, so changing the setting<em> may</em> ease the symptom...</p>

<p>There are two likely causes that I potentially see. The first is a firmware glitch. If you're not running the new 2.11, then I'd use this opportunity to go ahead and install it (after doing the hard reset PF advised). If the problem is somehow related to a glitch in the firmware, a combination of the two will almost certainly fix the problem.</p>

<p>If the problem is caused by the second, then no firmware fix is going to help, it is only going to get progressively worse. But at least it'd be easier to test conclusively. That would be that your shutter button is starting to fail. </p>

<p>As I said, it's easy to test. the 5D2 has the 'AF-ON' button on the back which also activates the AF. The next time you notice the failure, try using it. If AF works normally (w/ the AF ON button, while the shutter button fails to activate it), I would guess it's<em> very</em> likely that the shutter button is starting to fail. If not, then the problem is most likely linked to the firmware which responds to the 'AF ON' command, and NOT a physical problem.</p>

<p>You said you recently bought it used, how many exposures are on the camera? (EOSinfo will tell you easily) if a low to moderate number, I'd be surprised to see a failure, but if a higher number, it's certainly a reasonable possibility. - of course predicting such failures is kind of like staring into a crystal ball - often only good for a headache. The one thing I would consider as highly probable about the problem is that the seller most likely experienced it also, prior to the sale. </p>

<p>All that said, it's possible there is another culprit, but they are much less likely.</p>

 

<p>Thanks for you feedback.<br>

My C.Fn-III-1 is set to 0 not 1. </p>

<p>Upgrading the firmware was the first thing I did and it did not solve the problem.</p>

<p>The camera had very few actuations when I purchased it as been used almost only for filming.</p>

<p>Next time I will try the AF ON button as suggested.</p>