Gh2 - HELP! New type of horizontal banding?

[bmd]

Can anyone tell me what is causing the horizontal banding at the top of the wall outside of the bedroom in these two shots? I was testing a steady cam today and noticed my Gh2 (24p, flowmotion hack) was showing these horizontal bands along the top. Yes, I've had trouble with the already much discussed High ISO/Underexposed area (mine shows up as low as 400 ISO) and thought I would try the same work around...shoot at a shutter speed of 30. Didn't help, the first photo was with a SS of 30, the second is with a SS of 50. The banding looks different, but is clearly there on both. Part of me is hoping it has to do with the light coming in from the windows and reflecting off the lens...but I don't think that's it. Anyone had anything similar. Getting REALLY frustrated with all the crap that keeps popping up trying to shoot with this camera. Every time I think I'm getting used to the work arounds, something else comes up. I REALLY hope panasonic has read some of these forums and correct all of this banding issue in the GH3....it really makes the camera almost unusable in any kind of professional situation. Sigh.

BTW...the pics are frame grabs from video...not still photos.[attachment=288:photo-3.JPG][attachment=289:photo-4.JPG]

[QuickHitRecord]

You'll get less noisy results if you stick to the top line of ISO options (i.e. 160, 320, 640, etc.). I get those lines too. I think that most if not all GH2s do. Mine start showing up at iso 1250, so as a general rule I only shoot at 160 or 320. Here's hoping that the GH3 resolves this.

[kirk]

My understanding of the ISO issue was that you'd better avoid the top line??? Or arrive from one step above?

[Axel]

[quote name='kirk' timestamp='1346916312' post='17424']
My understanding of the ISO issue was that you'd better avoid the top line??? Or arrive from one step above?
[/quote]

That's what I do: When I wake up my GH2, it starts at ISO 1600. If I want i.e. 320, I go 1600→ 800 → 400 ↓320.

Did you dial down the saturation to -2?

And: I know I'll be getting stoned for that, but most of the colored-noise-issues simply don't show up with standard firmware.

[QuickHitRecord]

ISO bug and workaround: [url="http://youtu.be/N21mzRjJG74?hd=1&t=2m46s"]http://youtu.be/N21m...74?hd=1&t=2m46s[/url]

I came across a GH2 test a while back in which someone filmed a black surface (or just left the lens cap on) and enhanced the noise in post, which confirmed that the top line (ISO 160, 320, 640, etc) will result in less noise than the other ISOs. I'll post the test if I can find it again.

[kirk]

[quote name='Axel' timestamp='1346918979' post='17427']
That's what I do: When I wake up my GH2, it starts at ISO 1600. If I want i.e. 320, I go 1600→ 800 → 400 ↓320.

Did you dial down the saturation to -2?

And: I know I'll be getting stoned for that, but most of the colored-noise-issues simply don't show up with standard firmware.
[/quote]

Which is one reason why I shoot un-hacked B) Now ducking...

And I'll have to read up on the ISO issue again...

[bmd]

Yes, saturation and everything else was set to -2 Smooth. I've been trying to remember to do the step down method with the ISO, but I think I forgot when shooting this because I mainly was just testing out the steady cam. Hmmmm...if shooting unhacked

[bmd]

Sorry...fat fingers made me hit the post button prematurely. If shooting unhacked cleans up this crap I may have to consider going back to original firmware. I just feel like I'm freaked out everytime I use this camera and can't concentrate on anything other than looking out for artifacts.

[kirk]

I too have had the odd strange noisy recording, with my unhacked GH2. The slightest underexposure is punished hard. I recently had to shoot a white church surrounded by trees and with a dark red structure in the shadow on one side, lots of contrast on a bright sunny day... First take was perfect when viewed on a big screen... I had centered the histogram as best I could. But fearing the white wall was burnt through I made a second shot just a tad on the dark side... the dark red wall was now unbelievably noisy. This was while I still used the flat Nostalgic setting. Following a tip recently, I now use the Vibrant setting of all things, get much less noise trouble and files come much closer to the final look I want, reducing grading to a minimum...

[QuickHitRecord]

I couldn't find the test that I mentioned earlier so I just did one myself with four different GH2 bodies (two hacked and two unhacked). I can report that the bar of death seems to show up at ISO 2500 and will make your video unusable at ISO 5000. Because the unhacked cameras only go up to ISO 2500, you may be convinced that it is not a problem with them. But it is still there.

What surprised me is that my camera had this issue start to become a problem at ISO 1250 when I was running the Unified setting. But now that I am using Flowmotion 2.02, it only shows up (and less obtrusively) at ISO 2500.

At any rate, I would only recommend shooting at ISO 160 or ISO 320 with the GH2. Anything higher is just ugly.

Here are some screen grabs of FlowMotion footage shot with the lens cap on (noise has been enhanced for visibillity with a gamma shift and 3-way color corrector; file sizes compressed for posting here):

[attachment=296:ISO-160.jpg]
@ ISO 160

[attachment=295:ISO-320.jpg]
@ ISO 320

[attachment=294:ISO-640.jpg]
@ ISO 640

[attachment=293:ISO-1250.jpg]
@ ISO 1250

[attachment=292:ISO-2500.jpg]
@ ISO 2500

[attachment=291:ISO-5000.jpg]
@ ISO 5000

I have ISO 10000 too, but it's a bigger file because of the additional noise. I'd have to compress it beyond being a useful comparison to post here.

With regard to the ISO bug: I started with the higher ISOs and worked my way down to 160 when I was capturing just to be sure.

Panasonic really needs to address these problems with the GH3.

[QuickHitRecord]

Also, some of the camera bodies had significantly less noise at ISO 1250 than 640. But it's not an even spread of noise. There is significantly more noise on the right extremity of the frame. But the rest of the frame is much cleaner than 640. See example:

[attachment=297:ISO_1250.jpg]

This happened with one of the four unhacked bodies, and then with at least two of the bodies with the Vanilla 44mbps hack. I am not sure why this is happening. Must have something to do with the bug.

[kirk]

I have shot quite a few unlit interiors of old mills, medieval chrurches etc, and have had great success using 1600 ISO. Especially when using the Vibrant setting.