AF sucks on GH2 + Panasonic/Leica HX025 25mm lense (Or maybe I do smth wrong?)

T

Tim_

Member
here's video I've made using GH2 (unhacked) with leica/panasonic 25mm HX025

http://www.youtube.com/watch?v=1pyxQcxH0eg

Autofocus problem becomes very prominent after 10:40

Do you think this kind of crappy AF is normal, or I do something wrong?

Maybe the wide aperture (2.0-3.2 in this case) is reason for "drunk" AF?

There are many opinions on how great GH2 AF is on "native" panasonic lenses... Seriously, using it for more then 6 month I cannot agree so far even closely...

Any advice would be highly appreciated
 
AF is good on native lens compared to non native, AF is better on native lenses made specifically for video like 14-140. that said, a static shot like that one I would usually lock the focus. if you find it difficult by yourself, get a remote trigger cord or wireless and pre focus on you then switch to manual to lock. the 20mm will perform in the same way wide open also.
 
MR Fanny said:
AF is good on native lens compared to non native, AF is better on native lenses made specifically for video like 14-140. that said, a static shot like that one I would usually lock the focus. if you find it difficult by yourself, get a remote trigger cord or wireless and pre focus on you then switch to manual to lock. the 20mm will perform in the same way wide open also.
Click to expand...

thank you! But what exactly do you mean by "locking"? Manual focus?

I have a remote shutter.

On every lense I use (I have this pana-leica 25mm and 14-140) the AF seems like "breathing" (moving back and forth) when I half-press the shutter speed.

I also find that CONTINIOUS AF is not working properly (or at all), if by "AFC" why suppose it to move after the subject and keep it always in focus... Any tips on what options to switch in menu and on camera to make this work?

Thanx in advance
 
In your example the auto focus is triggering on motion near the center of the frame, sometimes you, sometimes the trees blowing in the wind. You can set a face recognition zone so the camera will track your face only.
Auto focus is dumb. It can't decide by itself what scene elements should be the center of focus. I have had similar problems shooting a beach scene from a screened porch where the camera can't decide whether to focus on the screen or the sea oats blowing in the wind. The lens seemed quite responsive though, not a lens problem at all.
In your scene since it is static, I would have picked an aperture that gives enough depth of field for your range of motion and set focus manually. There is no need for it to change.

ENG cameras I have used have a function where you push an autofocus button to set focus on a scene object and it locks when you release the button. Does a GH2 have this function?
 
Last edited:
I have that lens also in low light in searches a lot for focus. I think I'll have to start using it in manual mode as it really sucks at times.
 
why would you have your camera on autofocus for an interview shot like this?
Almost ANY camera including lens you use will... sooner or later adjust focus, IF YOU HAVE IT SET TO AUTOFOCUS.
You should turn off autofocus in your menus. Just prefocus and hit record. When you change shot, prefocus again.
The only time you would consider using auto focus would be for movement type shooting, like little kids running around or following some race from the sidelines.
The GH2 is amazingly fast at focusing, but its a DSLR #1, Your using an optimized PHOTO lens #2, and #3 you have movement going on in the background.
If going to make a video, you should ALWAYS be in control of your focusing. I would never let the camera decide my settings, especially the FOCUSING.
 
if your subject isn't moving, use autofocus to prefocus. then turn autofocus off. it's not necessary. and luckily on the gh2 all you have to do is flip the knob to manual
if you have to use autofocus, i would recommend a smaller aperture (more depth of field, more in focus). but that's only if you have to use it
 
You must log in or register to reply here.
Back
Top