GH2 Auto focusing in video while on Steadicam Pilot

Y

yoclay

Veteran
I am a current owner of several 5DMII's and about 30 lenses, including anamorphic, Leica M, old Olympus, Zeiss, etc.
Lately with the hacks and the inclusion of 25p (soon to be hacked I hope), I have been considering picking up a GH2.
I definitely like the idea of having a smaller carry around camera and the compatibility of several of my Leica M aspherique lenses.

However, what interests me most is having the possibility of AF while shooting video on my Steadicam Pilot.
I am not interested in buying a Preston, or wireless remote, etc for occasional stead work because it's not my main gig.
This generally means working with really wide lenses and stopping down a fair amount in order to insure focus.
One thing you don't want to do is touch the camera once things are balanced out, so AF could be really helpful.
As I often have the subject centered in the frame when in stead mode, I thought it could be possible to actually use the AF.
This of course would mean that I could use slightly longer focal lengths and narrower depth of field. Which would be visually great.

So my question is this, how viable is AF in video on the GH2? Is it too slow? Does the new firmware upgrade improve this ? (I have heard reports of this)
And... most importantly what lenses really work in AF mode? 14-42, 14-140, etc? Olympus lenses? Will the new X series be better for this?

Thanks in advance for your responses.
 
yoclay said:
I am a current owner of several 5DMII's and about 30 lenses, including anamorphic, Leica M, old Olympus, Zeiss, etc.
Lately with the hacks and the inclusion of 25p (soon to be hacked I hope), I have been considering picking up a GH2.
I definitely like the idea of having a smaller carry around camera and the compatibility of several of my Leica M aspherique lenses.

However, what interests me most is having the possibility of AF while shooting video on my Steadicam Pilot.
I am not interested in buying a Preston, or wireless remote, etc for occasional stead work because it's not my main gig.
This generally means working with really wide lenses and stopping down a fair amount in order to insure focus.
One thing you don't want to do is touch the camera once things are balanced out, so AF could be really helpful.
As I often have the subject centered in the frame when in stead mode, I thought it could be possible to actually use the AF.
This of course would mean that I could use slightly longer focal lengths and narrower depth of field. Which would be visually great.

So my question is this, how viable is AF in video on the GH2? Is it too slow? Does the new firmware upgrade improve this ? (I have heard reports of this)
And... most importantly what lenses really work in AF mode? 14-42, 14-140, etc? Olympus lenses? Will the new X series be better for this?

Thanks in advance for your responses.
Click to expand...







In decent light I think that the AF will be much better than you hoped for.

Even indoors, AF is really not bad at all - some hunting, but not much (and it always locks focus in the end)

I have the 'X' 45-175 and, imo, you will see no AF improvements over the non-'X' lenses.

I find the 14-45mm to be pretty fast indoors & out.

The 20mm f1/7 seems better after the recent FW update. It's the noisiest focus of all the Panasonic lenses - but if you were filming a 'normal' situation (say a family event, or something ike that) the focus noise wuld be inaudible.

I also have the 14-140mm, which is supposed to be *the* video lens. All I can say is that it's no better than the 14-45mm, and is *not* a completely stepless aperture as some claim. It's a nice enough lens, but I don't think it stands head and shoulders above the others (and is the most expensive option - apart from the really wide stuff)

imo you will gain decent AF - but (after your Canon) you might be shocked by the noise levels - and, particularly, by the clearly defined horizontal band that appears in underexposed portions of the image.

Personally, I'm seriously contemplating a 60D because of this issue - so I'll be interested to see just *how* bad the 60D AF is :cheesy:

On balance, I think that I'd rather have to rely on MF and have clean low light mages - alrtough I realise that MF isn't an option for you with a steadycam.
 
I have a related question: which lenses do people find have the fastest, most accurate auto-focus for video? I have the 20mm and, besides being noisy, it doesn't feel fast and it seems to hunt quite a bit (even with the 1.1 firmware).
 
Thanks so far for the suggestions. Currently, I am looking to know how AF functions with 25mm (50mm equivalent on 5D) and beyond because wide angle is the norm for steady-ing.
One question, this banding issue - was that not something that was resolved with some of the higher bit rate hacks?
 
25mm and up, is not ideal with steadicam and autofocus.
Only if you can close to f/56 - 8 ....

The banding issue can happen only in very low light or underexposured images and high iso.

If you exposure to the right , with fast lenses, you will not have any issues.
Here is an example with newer firmware, in a very low light room , fast lens (20mm f/1.7) and exposure to the right.

 
Framerate said:
imo you will gain decent AF - but (after your Canon) you might be shocked by the noise levels - and, particularly, by the clearly defined horizontal band that appears in underexposed portions of the image.
Click to expand...

I am confused... You say that the noise level is higher on GH2 than on 5DmkII??? I shoot with GH2 at 800ISO with little to no grain. Try doing that with the Canons...
For the banding, I read about it, but never actually saw it on my camera, even while doing tests especially to see it. It is only a few defective cameras.

GH2 is amazing for Steadicam.
- It is super light, maybe even sometimes too light and you may consider adding weight to the camera itself.
- it is small and therefore can go anywhere.
- the AF is really good. Use a prime HD lens from Panasonic for best result.
- the swivel monitor is a great bonus as you can go high and low without adding an external monitor.
- SUPER CHEAP! check Adorama, the camera is $800 with a lens http://goo.gl/KxX9P
 
Phenixone said:
I am confused... You say that the noise level is higher on GH2 than on 5DmkII??? I shoot with GH2 at 800ISO with little to no grain. Try doing that with the Canons...
For the banding, I read about it, but never actually saw it on my camera, even while doing tests especially to see it. It is only a few defective cameras.
Click to expand...

Sadly, it's not. My GH2 (just returned) was a September 2011 build - which shows that the problem continues unabated. Amazon will send me another one - but I have little doubt that one will be exactly the same. After that, I'm going to look at another solution, I think.

I've some some lengthy testing and found that the band is present in both interlaced and progressive mode - FW 1.1 had no effect on the problem. It's decidedly more pronounced in progressive mode, but it also there when shooting 50i (underexposed)

Good light - no issue, you'll never see it (although I'm sure it's stil there) That's why the fast lenses are the answer - simply because they enable optimum exposure. The downside with that is the fact that you need fast (read expensive) glass just to keep away from underexposure.

That's OK as far as it goes - but what happens if you need a telephoto lens, and can't afford something exotic? Even an f/4 is not fast enough to avoid the underexposure that reveals banding.

Anything below 1.5 EV underexposed and you're stepping into bandland. I really don't see how it can be avoided, particularly indoors - in any room there are bound to be parts that have less lighting, which is when your exposure will fall, which is when the banding wil appear.

If you enable the focus grid on your GH2, the band will appear just below the 3rd horizontal grid line @ 50th shutter. Turn to 30th shutter and the band will be just below the bottom grid line. Go to 25th shutter and the band will move down and off the display.

Conversely, move from 50th to 100th and the band will move upwards..etc.

It's nothing whatsoever to do with the type of lighting - I think that, althouh shutter speed determines where/if the band appears, it's simply because the slower speeds restore the correct exposure.

It doesn't have to be indoors, either - any scene with significant shadows will be enough to trigger it.

I don't want to be unduly negative about ti - and the GH2 has some great features that help to mitigate the issue. However, I 'personally' think that there are/will be other cameras (Nex-7, hopefully) that offer all the features, and more, which are not compromised in this way.

Yes, they might cost a bit more - but (and again this is personal) I'd rarher pay an extra three or four hundred pounds and have something that I was really pleased with, rather than making the best of a bad job because it's cheaper.

Perhaps the *real* gripe should be *why* haven't Panasonic done anyrthing about this issue, I absolutely refuse to beleive that they are not fully aware of it - and the latest FW update would have been an ideal opportunity to remedy it.

Sadly, if they didn't do it then, they probably never will.
 
Sorry to hear that, i had the same problem too, but now with the right lens ... not anymore.
You dont expect to shoot nice video, indoors with kit lenses... in any camera.

I have sony nex 5n also (except gh2) , the king of mirrorless as regards low light video... BUT not with kit lens!

I demoed some video from 5n and kit lens to my friends (editors, directors) and they lough .
Then i demoed some "other" footage , with fast lens (sony 35mm 1.8) and they were amazed by the difference.

You want nice lenses to show some real good work.
There are many cheap and bright lenses... i have Samyang 85mm 1.4 (in GH2 is 170mm 1.4 !!!)
With this lens (very cheap) , you can shot anywhere (if you want a fast tele)

Finally , dont forget , you can shoot with speed 1/25 and the problem is gone .
I tried it and it worked every time.
 
toxotis70 said:
Sorry to hear that, i had the same problem too, but now with the right lens ... not anymore.
You dont expect to shoot nice video, indoors with kit lenses... in any camera.

I have sony nex 5n also (except gh2) , the king of mirrorless as regards low light video... BUT not with kit lens!

I demoed some video from 5n and kit lens to my friends (editors, directors) and they lough .
Then i demoed some "other" footage , with fast lens (sony 35mm 1.8) and they were amazed by the difference.

You want nice lenses to show some real good work.
There are many cheap and bright lenses... i have Samyang 85mm 1.4 (in GH2 is 170mm 1.4 !!!)
With this lens (very cheap) , you can shot anywhere (if you want a fast tele)

Finally , dont forget , you can shoot with speed 1/25 and the problem is gone .
I tried it and it worked every time.
Click to expand...



The problem, from the OP's pov, is that he needs autofocus on a steadycam - and that means native Panasonic lenses, which are slow.

If he's filming outside that might not be an issue - but if he's planning to shoot indoors using that set up he might well experience the banding issue.

I considered the Nex 5n - but really too tiny for my taste. OTOH, f the Nex-7 hadn't been delayed I'd be using one now :cheesy:

As far as Canon goes - I've seen some really clean low light footage taken with kit lenses - but, of course, the AF doesn't seem up to much.

I'll see what my replacement GH2 is like - but I must admit that, n my heart, I've already written it off.
 
When in continuous autofocus mode (AFC) what setting is best to put it on? Face detection? 23-arera focusing? Center focusing?
 
Good post. Well this is exactly what I do on my steadicam system. I opted for some scottish budget decisions and went with the glidecam HD4000 and I modified it and then I bought the steadicam Merlin arm and vest. I can tell you that it's amazingly AWESOME to shoot Steadicam on the GH2 and even better on the AF100. THere's really one major element to consider and that's the lightweight nature of the GH2. What I do is mount several weight plates, an LED light, and some sled weights. I also try and adjust the cg on the rig placement and with this larger inertia and mass, the rig flies a lot better. The other major thing that I think is necessary even on the GH2 is an ND fader for all outdoor work. Touching The camera more than just that fader is a pain in the but... THis also easily allows you to set a higher Fstop on the camera but ND down.

I'll upload some video samples for you to check out. And as far as lenses, the 20mm 1.7 is not very good at all on the rig, but it does work under the right situaion. By far, the 14-140 doe a remarkable job. I have run all over the place with my rig and never had any major focus issues. I'm hoping to get a wireless follow focus to go along with my wireless video transmitter.


So I can say, the GH2 on the steadicam is awesome. The HMC150 I have is even better. Easier to get to CG and it's just more forgiving on focus as most of the time I just set it at 8 feet and I'm good. Can't always do that with DSLR.
 
You must log in or register to reply here.
Back
Top