5D3 - intermittent focus and shutter button "failure"

chrisdg

Hello,

A couple of months ago I replaced my Canon 50D with a 5Dm3. My primary use lately has been relatively low-light (small club) rock concert photography...slightly better than dance floor lighting perhaps. No flash.

I'm using the 24-70 f2.8L almost exclusively, wide-open, high ISO, and typically about 5 feet from the nearest subject. In these conditions, grabbing focus on a contrasty area (performer's face, guitar, etc) can be a bit of a challenge - i achieve focus on maybe 65% of my half-shutter presses...and the rest of the time, no focus = no actuation. But that's not the problem I am worried about... a few times per night when I am trying to find a focus point and failing to do so in a fairly rapid-fire series of attempts, the shutter-button will simply "lock up" and not allow me to grab focus on anything, anywhere. The button simply dies. I am forced to restart the camera. After restart it will go back to it's "normal, but still disappointing self" and then eventually fail again at some point. Anyone else experiencing this with a 5D3 at concerts, wedding receptions, etc? Does it sound like I'm doing anything wrong?

For AF mode, I have tried "One Shot" "AI Focus" and occasionally "AI Servo" (with Case 1 and Case 3). For point selection method, I have tried the various Spot-AF, Expanded-Spot AF, and Surround-Spot AF settings. Metering is tied to focus point. None of this seems to change the situation. When in One-Shot mode, I do have the camera set to Focus Priority over Release Priority (cause I do want the subject to be in focus).

I will call Canon soon, just wanted some of your insight.

Thank you.

ziggy53

Those environments are notorious for being low light. Low light and autofocus, especially of human subjects, is bound to result in AF slowness and AF error.

I strongly recommend using a device with an AF Assist lamp which projects a deep red pattern on the subject(s). This alone will improve AF speed and AF accuracy.

Suitable devices are:

One of the Canon 580EX series flashes. You can turn off the flash output so that there is no flash distraction. The AF Assist lamp is almost perfect for this work, projecting a pattern that is easy for the AF section to lock onto for focus.

A Canon optical wireless flash master transmitter, aka an ST-E2. While not as bright and not as good a pattern as the 580EX, it's still very useful. No visible flash. Relatively small. Downsides are cost and battery type.

A Yongnuo ST-E2. Not as good as the Canon version but still useful. Common batteries.

chrisdg

Thanks Ziggy. I was going to bring my new 600EX-RT flash into the venue last night for that purpose, but forgot to do so. Next time.

btw - according to another forum, a guy stated "I received an email from hkyongnuo. The 5d3 is not compatible with the Yongnuo ST-E2." I'm not sure to what extent it's incompatible, so Ill check on that. I'd prefer a smaller, cheaper device on top of the camera, cuz people are thrashing about sometimes and a full flash is subject to breaking off the mount if contact is great enough. Unfortunately, I sold my Canon ST-E2 when I upgraded to the 600 series.

As for the shutter button just becoming completely non-responsiveness, that I will call Canon about. Just wondering if anyone has experienced similar.

Matthew Saville

The guys in my studio have now gotten three different 5D mk3's, and all of them seem to have a similar "hesitation" when focusing in one-shot. I have done extensive testing using the 24-70 L and the Nikon 24-70, comparing the 5D mk3 and the 5D mk2 and the Nikon D700. The 5D mk3 clearly has a slight hesitation to confirm and lock focus in extremely low light conditions. Even the 5D mk2 is quick to confirm focus, although of course it isn't nearly as reliable with regards to accuracy.

Unfortunately, so far it seems that this is just the price you pay for extreme accuracy in extremely low light. If I am not mistaken, the 5D mk3's AF is one of the first to be rated down to -2 EV, so Canon is venturing into new territory here. I would love to see someone perform a test to see where the 5D mk3 begins to falter, if it is only with subjects down at the -1 or -2 EV range, or if the issue also happens at brighter levels. I personally have not noticed the 5D mk3 "choking" even in half-decent light...

=Matt=

chrisdg

Matthew Saville wrote: »

The guys in my studio have now gotten three different 5D mk3's, and all of them seem to have a similar "hesitation" when focusing in one-shot.
=Matt=

Thanks Matt - I remember you discussing this problem early on in the 5D3 days. However, the hesitation is one thing, but in my case, the shutter button eventually "dies" after repeated attempts to focus. Even if I pause for 5-10 seconds, point at something bright and easy, the shutter button simply does not respond for focus nor actuation. I am forced to turn the camera OFF and ON again to resume functionality. It happens about 3 times during an average 90 minute session. of course, it always seems to happen at the worst moment possible

Anyone in your studio experience this?

Cheers.

Cuong

Matthew Saville wrote: »

...The 5D mk3 clearly has a slight hesitation to confirm and lock focus in extremely low light conditions....

I can affirm that the 5D3 AF confirmation hesitation in low light is definitely there, even with an AF assist pattern from a flash. The delay might last a couple seconds and that's an eternity to miss a shot.

Cuong

Matthew Saville

chrisdg wrote: »

Thanks Matt - I remember you discussing this problem early on in the 5D3 days. However, the hesitation is one thing, but in my case, the shutter button eventually "dies" after repeated attempts to focus. Even if I pause for 5-10 seconds, point at something bright and easy, the shutter button simply does not respond for focus nor actuation. I am forced to turn the camera OFF and ON again to resume functionality. It happens about 3 times during an average 90 minute session. of course, it always seems to happen at the worst moment possible

Anyone in your studio experience this?

Cheers.

Not that I know of, however you may want to turn on "focus hunting" in the AF options. I forget where it is, but that might be what is causing your shutter button to flat-out "give up".

BTW, are you using the red flash beam in these tests? Sorry if you mentioned it already but I was just wondering. The 5D mk3 may indeed have some slight hesitation problems in one-shot in extremely dark light, but I've never heard of it flat-out "giving up"...

And again, I'd love to see an EV meter reading to determine how close you are to the camera's rated threshold of -2EV. (BTW for any newbies out there, I'm talking about an actual brightness measurement, not simple negative compensation. ;-)


=Matt=

Dan7312

I tried getting auto-focus lock with a 5D3 / 70-200II. No special setup, no flash for focus assist, just a room partially lit from another room that got darker as you went deeper into it.

I did incident readings with a Sekonic L-758DR which goes down to -2ev. I was focusing on curtains, edges of windows, that sort of thing.

I was as able to get focus lock at lower than -2ev. I did a series of tests and progressively got locks at -1.2ev, -1.5ev, and then at the point the level was below the range of the meter.

At below -2ev it took 2 seconds or so to acquire focus. I didn't check to how good the focus, I just waited for focus confirmation beep.

Edit: I cranked up the iso so I could see something and at least from looking at the LCD and factoring a hand held shot, it looks in focus.

Matthew Saville wrote: »

And again, I'd love to see an EV meter reading to determine how close you are to the camera's rated threshold of -2EV.
=Matt=