Autofocus on GH2 versus GH3 at DVinfo.net

Jim Snow · February 6th, 2013, 03:46 PM

I have a GH2 and a GH3 on the way. A problem I have with the GH2 is that when I use the 20mm f1.7 pancake lens in low light it can lose focus when shooting in autofocus mode. When this occurs, it goes extremely out of focus and has a difficult time recovering. For those who have a GH3, how does it compare to the GH2 with this issue?

Bruce Foreman · February 8th, 2013, 08:41 PM

I haven't run a comparison between the two cameras but low light is potentially problematic for autofocus in general. I was doing some night street scene tests with my GH3 and the 20mm just a few nights ago and on my street (which isn't really well lit) it "lost focus" right away so I switched to manual focus for the rest of the test series.

If you have MF ASSIST set to ON and AF+MF ASSIST also set to ON, you can "half press" the shutter button for autofocus then hold that half press while putting pressure on the focus ring, the magnified assist will "kick in".

While set for Manual Focus putting pressure on or moving the focus ring will cause it to "kick in" and touching the shutter button lightly will allow your viewfinder to go back to normal.

William Hohauser · February 9th, 2013, 06:38 PM

While the GH3 is a little better in low light, I have not experienced it as holding the auto-focus better in low light. The auto-focus does seem to be quicker although. The GH2 is frustrating as it might work fine in low light for an hour and then suddenly go out of focus and stay that way without any change in the subject or background.

Chris Duczynski · February 9th, 2013, 11:11 PM

I just don't trust autofocus when shooting wide open around F2.8. The DOF is so narrow with 45mm and up that expanded focus on manual is really the only way to go.

February 6th, 2013, 03:46 PM	#1
Jim Snow Trustee Join Date: Mar 2009 Location: Santa Clara, CA Posts: 1,104	Autofocus on GH2 versus GH3 I have a GH2 and a GH3 on the way. A problem I have with the GH2 is that when I use the 20mm f1.7 pancake lens in low light it can lose focus when shooting in autofocus mode. When this occurs, it goes extremely out of focus and has a difficult time recovering. For those who have a GH3, how does it compare to the GH2 with this issue?

February 8th, 2013, 08:41 PM	#2
Bruce Foreman Trustee Join Date: Nov 2006 Location: San Angelo Texas Posts: 1,518	Re: Autofocus on GH2 versus GH3 I haven't run a comparison between the two cameras but low light is potentially problematic for autofocus in general. I was doing some night street scene tests with my GH3 and the 20mm just a few nights ago and on my street (which isn't really well lit) it "lost focus" right away so I switched to manual focus for the rest of the test series. If you have MF ASSIST set to ON and AF+MF ASSIST also set to ON, you can "half press" the shutter button for autofocus then hold that half press while putting pressure on the focus ring, the magnified assist will "kick in". While set for Manual Focus putting pressure on or moving the focus ring will cause it to "kick in" and touching the shutter button lightly will allow your viewfinder to go back to normal.

February 9th, 2013, 06:38 PM	#3
William Hohauser Inner Circle Join Date: Dec 2005 Location: New York City Posts: 2,650	Re: Autofocus on GH2 versus GH3 While the GH3 is a little better in low light, I have not experienced it as holding the auto-focus better in low light. The auto-focus does seem to be quicker although. The GH2 is frustrating as it might work fine in low light for an hour and then suddenly go out of focus and stay that way without any change in the subject or background. __________________ William Hohauser - New York City Producer/Edit/Camera/Animation

February 9th, 2013, 11:11 PM	#4
Chris Duczynski Major Player Join Date: Feb 2010 Location: sydney Posts: 304	Re: Autofocus on GH2 versus GH3 I just don't trust autofocus when shooting wide open around F2.8. The DOF is so narrow with 45mm and up that expanded focus on manual is really the only way to go.