GH2 showing fixed darker band/stripe 20 pixels high across footage

tinyrobot

I did another test and shot a white pillow underexposed -2 at 3200iso. It was so easy to see the banding jump around when switching the shutter speed. It also had banding at 1600iso, but these examples from 3200iso are more pronounced. A little disappointed this time as it was really easy to get the banding without really trying. I suggest others to also shoot a white pillow or whatever in a dimly lit room to test.

I also got the banding when I pointed it at a large white plastic container that took 2/3 of the composition.

There was something weird. When I played with iA, and set it 3 stops underexposed, two vertical lines would come, meet and cross from top to bottom like a gyroscope when I tilted the camera. I don't know what this means, maybe algorithm problem that can be fixed in a firmware?

Mine was made in June, so anyone with the latest one that can test?

sam_stickland

@tinyrobot That's interesting. I notice my band only on the darker areas of the shot, but you mention that you see yours on the lighter.

tinyrobot

I've seen this horizontal banding on mine at 1000iso, 1600iso and 32000iso, but you really have to push the camera to achieve it. I shot a flatly lit white wall and a refrigerator and it does show when it is around 1 1/2 - 2 stops underexposed, but most of the time I won't be shooting these scenes. The amount of noise and ugly smears at 1600iso is a little disturbing though, but with something like Neat video, maybe it can be fixed. My camera was made in June 2011 so it is a fairly recent batch. I don't believe anything was fixed in newer batches and I believe all the cameras exhibit this behavior. You just have to know what to shoot and what to look for. I could be wrong, but unless someone who has experience and gets a replacement and puts it under the same level of stress, I'm going to stick to my theory.

I decided to shoot night street scenes with lots of people walking by with my 14-140mm at 1600iso and 3200iso. Generally speaking no one will notice the band. Occasionally, when someone with a light colored shirt passes by and I pause it, I can see this. But with typical scenes it won't be noticed, unless you like to shoot flat light colors underexposed that take most of the composition.

The two attached files show one with banding and one without banding. Both were using the same iso in the same scene (can't remember if it was 1600iso or 3200iso, but it looks like 3200iso).

sammy and sam_sickland, did you try shooting real world scenes and if so, does the banding show often?

*revision* I take it back. You don't have to really push it to see the banding. It will show like in the first picture when a swath of color is obscuring part of the frame. This sucks!

crunchy

At first sight it looks like there exists an artificial light with very fast fade-off times in one power supply cycle (e.g. LED, CRT screen with some special pattern on the screen or similar devices synchronous with camera's frame rate or multiplications of the frame rate). Different shutter speeds might change the position of the band. Of course, I suppose that you already eliminated such causes.

sam_stickland

@stefanos I plan on capturing the FPN at different shutter speeds and building my own AE presets to deal with it.

stefanos

@sam_sickland
I looked at the video above, I'm guessing the first lower band is 1/50 shutter, because I have seen the exact same thing on my GH2 at the lower part of the frame, and I didn't know about the shutter changing that, which is both intriguing and infuriating. I'll check those threads too, sounds interesting. The problem is that sometimes I don't see it at all, other times it destroys the shot. Panasonic is retarded.

sam_stickland

Anyone got any idea how that might help a CMOS sensor?

cj7

I think that the serial may tell us about when the camera was manufactured or shipped.

I guess, I am just guessing that my GH2 could have been made in October (10th letter of alphabet, J in the 4th letter of my serial #) in 2010 (0, the 3rd in my serial #). Yours could have been made in March (C) 2011 (1).

I will try to sort out that problem with post production (using Adobe Premiere) later when I have time.

sammy

my gh2 says made in china , the serial starts with WE1CA ..maybe they all have it,you just got to look for it i guess..just let me make this clear,that in real life situation shooting, with lighting etc, i dont think this will become an issue ..this might be an issue if your inside the house at night with kit lens and one light on only, you may than turn up the iso, i start seeing it at 1000 with underexposure ..

*Ian just replied to my video, he is saying it is a known issue with the early GH2's,but newer ones dont have this issue, anyone with a new GH2 can test this for us, thanks

cj7

My GH2 (made in Japan) with the 14~42 kit lens (made in China) has the fixed darker band/stripe problem.

My GH2's serial number begins with FT0JA. The lens' serial reads SA0SC00**** What is yours?

sammy

my test was with a nikon 50mm 1.8, i seen it with all my lenses

driftwood

I read somewhere its a prob with the 14-42 lens, can you confirm the problem on any other lenses? I have two early version gh2s and get no problems with an array of different lenses inc 14-140, 7-14 and OM 50/1.2, FD 50/1.2 etc...

sammy

@sam_stickland
is this what you seeing?this is my gh2 ,high iso,changing shutter speed makes that line go up

cbrandin

@sam_stickland

I just take a screen grab and use Photoshop "levels" setting the endpoints around the edges of the histogram. It's ugly as hell, but you can see everything.

I think the FPN noise with the GH2 is actually pretty good. All digital cameras have FPN unless they have just crushed the blacks.

Be prepared to be unsettled when you do the levels thing, though - it looks terrible no matter how good the camera is.

Chris

sam_stickland

@cbrandin What process did you apply in Photoshop to reveal the FPN? Would you say it was excessive or average for a GH2 at this ISO and exposure (high and under exposed)?

brudney

cj7-> it does, as it's a sensor issue. obviously 20mm 1.7 is a fast prime, so you have to be pretty heavily underexposed at high ISO to start noticing it, but it's there:)

and yes, the stripe is visible on the LCD (when you know what to look for).

cj7

@sam_stickland

hello, nice to talk to you & thank you very much for a response!

>f/1.7 20mm pancake
I heard a lot of good reviews about the lens. So I am also thinking to buy one. Hopefully the lens does not have the problem of banding stripe....

>>LCD
Maybe the stripe was only obscure with the lens at 14mm, which was not just showing (or visible) on the LCD screen.

sam_stickland

@cj7 The images I attached where shot at 14mm, f/3.5 on the 14-42mm/f3.5-5.6 lens.. I was doing these shots to get a feel for how much light I need, so I wanted the aperture as wide as possible.

I'm going to get the f/1.7 20mm pancake which is two stops faster than the 14-42mm so hopefully I won't have much need for 3200 ISO. To my eye it's too noisy for use, particularly all the FPN.

Oh, I don't think the LCD has the resolution to show this sort of FPN.

cj7

hello, I just wonder, what happens if you set the zoom to the widest? (14mm in case of my LUMIX G VARIO 14-42mm/F3.5-5.6).

I have had the better chance to see the stripe in movies shot in a darker room with few lights on, high ISO etc.

(note: the preview image you see in the LCD seems to change accordingly depending on video recording status. what you see in the LCD is probably close to what you get as a result. So, if you see the banding while recording, you are very likely to have movie files with the band stripe).

sam_stickland

@sammy Don't touch the sensor - the manual recommends to use a gentle air blower. Check the manual for the exact instructions, IIRC it's near the back.

sammy

i see that line also, at high iso and little underexposed ..by the way what is the best way to clean the sensor,what products to use?i have a few dust particles that seem not to want to leave with internal pixel refresh and sensor cleaning option , i see them most at f11 and up

sam_stickland

@brudney Nothing like a bit of quality control!

brudney

dark spot that was the main reason why I sent my previous GH2 back. Thankfully the new one doesn't have THAT particular issue anymore.

sam_stickland

FYI, I've been able to significantly reduce the visibility of this banding in After Effects like this:

- Create an adjustment layer over your footage, masking out the band
- Raise the gamma in the adjustment layer until the band is less visible (I used Colorista, and it's a very slight raise in the midtones 1 -> 1.0321)
- Duplicate the original footage, place it above the adjustment layer, then set the adjustment layers Track Matte to "Luma Inverted"

The final step is necessary because the band is more visible on dark areas than light areas. If you don't do this the raise in the gamma will brighten the lighter areas of the image too much.

What a pain in the arse! But at least the settings should be the same for each shutter speed.

I think I will return the camera as other people have had luck doing that :/

brudney

sam_stickland: yes, seems like. although it's funny that the guy's serial number is the same as mine, yet I can still see the horizontal banding at high ISOs ;) anyway, it may be a similar situation as the one with GH1. Some reported very heavy FPN, some said they could hardly notice it. So it's either Panasonic selling batches of both good and bad cameras or just a difference in people's perception:)

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