Low Light Streaks - Is my camera faulty?

upshot said:
I was happy to see that additional adapter! Anyway, I have a couple of batteries so I ran it for 2 HRS. I think (after killing chicken) that it appears a lot better at 640 now. More testing will tell.

The G1 definitely has a different iso character. More characteristic grain and small blocking (which I'd actually prefer because noise filters recognize this). Although it's noise celing IMHO starts around 400-500 whereas the GH seems to be toward 800.
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Two hours? I left my camera on in a low light situation for much longer and I haven't seen any difference.

Maybe the trick works in some situations but I wonder if it's only a temporary solution and if steaking will reappear the next day, after the camera cools down.
 
I like to shoot in some extreme low light situations with the GH1 and I have only noticed banding on a couple of shots. It certainly is no deal breaker if you overexpose slightly.
 
We've been shooting some exceptional footage all week with it. I sincerely doubt the banding is something that just "goes away" through some mystical process or some burn-in or whatever. I think it's just that as people learn how to use the camera, they *quit underexposing*.

Near as I can tell, if you have something 2 2/3 stops below "proper" exposure, you'll have bands in it. Done. End of story.

The bands actually can start faintly showing up at 2 stops under, and get more visible as you go further into underexposure. Get to 2 2/3 and they're easily seen. So -- don't do that.

Overexpose, no banding. Underexpose, get banding.

No two ways about it, no way to "fix" it, no changes are coming to save us from it, so -- monitor your exposure. Look for banding in the viewfinder. If you see it, change your exposure. If you don't see it, shoot the footage.

The footage, by the way, ranges from excellent to astonishing, when considering the price point of the product. We have an excellent, excellent director of photography (DVXUser's own Vincent Pascoe) and he is making this GH1 sing.
 
Barry_Green said:
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Near as I can tell, if you have something 2 2/3 stops below "proper" exposure, you'll have bands in it. Done. End of story.
.....
Overexpose, no banding. Underexpose, get banding.
....
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Ok - but isn´t it always a mix of well exposed + underexposed areas in the most indoor lowlight shots? So there will be almost always some people (or whatever) in the shadow areas (underexposed). And they will get most likely the streaks in their face!?

 
But presumably even in a properly exposed picture (as a whole) there will be areas that are underexposed. For instance if I correctly expose the lit side of someones face, the shadow side could easily be a couple of stops under. So how do I avoid banding then?

I guess the solution is to slightly overexpose the picture as a whole whilst avoiding blowing out highlghts.

(Capice - you beat me to it!!)
 
The more I use the GH1... I think it actually 'loves' detail. you can underexpose with no problems if there is lots o detail but large swaths involving a mix of blue/red channels (unfortunately like people's faces filling the screen) you really run the risk above iso 640.

Has anyone else noticed this too? The green channel is really smooth (in fact incredible even at iso1600)... but the red and blue channels when faced with a big blob or wall starts to show the banding. Like the example above... see how the hair is not the an issue (detail) but the cheek IS (big swath of subtle blue/red channel mix)

I agree with capice and nathankw's sentiment though... It's like simply 'not underexpose' is not an option you want some contrast or deep shadows. The interesting part is that beyond say 2 stops is not a problem! Very dark areas STAY amazingly noise and banding free even at iso1600.
 
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upshot said:
The more I use the GH1... I think it actually 'loves' detail. you can underexpose with no problems if there is lots o detail but large swaths involving a mix of blue/red channels (unfortunately like people's faces filling the screen) you really run the risk above iso 640.
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Agreed. Mix lighting conditions are really very pleasing with the camera. Just remember to turn off AWB.

upshot said:
Has anyone else noticed this too? The green channel is really smooth (in fact incredible even at iso1600)... but the red and blue channels when faced with a big blob or wall starts to show the banding. Like the example above... see how the hair is not the an issue (detail) but the cheek IS (big swath of subtle blue/red channel mix)
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Yes, green is the cleanest. Most likely from the extra sampling of green in the bayer pattern.

upshot said:
I agree with capice and nathankw's sentiment though... It's like simply 'not underexpose' is not an option you want some contrast or deep shadows. The interesting part is that beyond say 2 stops is not a problem! Very dark areas STAY amazingly noise and banding free even at iso1600.
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I disagree. At lower ISOs, the camera is much, much cleaner.

As a general rule FPN is most noticeable when the entire shot is 'greatly' underexposed, but not completely black (at a higher ISO/gain level.) The good news is that most often people are not shooting interior scenes this way. It is not only possible to time indoor scenes shot on-exposure to have a low level of ambient light- it is generally a recommended practice (in many scenarios) when shooting film.

If anyone plans to show GH1 images on a really big screen, I recommend to test the ISOs first. Don't assume that anything above 400-500 ISO is going to be as clean or smooth as anything below. But of course I believe that the GH1's 400 ISO setting actually has the sensitivity of 2500 ISO, so your mileage may vary.
 
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Just to ease people's fear of banding...it's not a problem for me.
I've had my Gh1 for a couple weeks.

Initially, I nearly wrote the cam off as a toy because of banding. Then I simply realized I was using it wrong...
Banding only shows up when you force the cam to do too much (too high iso, shutter, etc.)

Treat the Gh1 as you would any other camera. If the scene is too dark, light it up and don't worry about banding.

The cool thing is... sometimes, you can shoot at 1600 iso, and not have any banding at all.
 
Noise and sharpness are related - the TZ5 uses heavy noise reduction to give the impression that it can manage in low light, but that results in loss of resolution. Try increasing the noise reduction settings on the GH1 to get a comparable result. Also, try the AVCHD recording mode, and do delve into Creative Motion Picture mode - in all other modes, the GH1 uses various amounts of automated settings (for instance, in normal photo aperture priority mode, the video is actually being created in program mode).
 
dunca said:
TZ5 zoom video is much shaper and has more resolution as you can see in the example frames.
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No....it's called artificial sharpening. They both seem to produce the same detail but the TZ5's sharpenig needs to be tuned down so it doesn't look so harsh. For example....look around the edge of the white chair againts the door.
 
capice said:
Ok - but isn´t it always a mix of well exposed + underexposed areas in the most indoor lowlight shots? So there will be almost always some people (or whatever) in the shadow areas (underexposed). And they will get most likely the streaks in their face!?
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Yes.

True.

So don't make that be the central focus of your image.

We shot in all sorts of light conditions, and I was the "pixel police" all week, looking to see if the GH1 had screwed us over on any of those shots. And it never did. I finally had to point out some pulsing banding to Jack and Vincent, they'd never seen it on the footage, when it was there plain as day. But it was in the shadows, and on a well-composed, well-lit shot, your attention would never be dragged over there.

I pointed out some mud and "monet" on grassy trees, and Jack nearly slapped me for pixel-peeping. Because I guarantee you, nobody but me would ever notice it. It's a beautiful wide-angle overhead booming crane shot, with an ambulance and three police cars and actors and photographers all around, at night, and yeah, there's a little mud in the grass -- but who's looking at that?

So -- the rule stands -- if you underexpose by about 2.5 stops, you're going to see banding. Nothing you can do about it. So don't let the main focus of your image be underexposed by 2.5 stops! If it happens in the background, then yes it'll be streaky in the background.

If you want to have your shot underexposed by 2.5 stops, then expose it properly on-set and then bring it down in post -- voila, you get your 2.5-stop underexposure but you avoid banding entirely.

Banding shows up under two requirements: a) the area must be underexposed by at least 2 stops, usually 2.5 stops or more, and b) it has to be largely devoid of detail (meaning a flat surface, skin, paper, a wall, etc). Those are the scenarios under which it will happen, and it will *always* happen, no matter what your ISO setting. If there's lots of detail in those shadows, you won't see or notice any banding or streaking. If it's a large flat surface, hello banding.

You want a 4K sensor with a nearly-full-frame 35mm cine image size with interchangeable lenses that can use cheap lens mounts, all for $1500? This is the compromise you have to deal with.

Truthfully, using a good cinematographer, we never really had to stress about it. We just shot and it always looked good. Yes, pixel peeping can reveal faults, but I would be surprised if anyone was to look at our footage and was to then complain about it. The GH1 produces incredible results considering its price tag.
 
Barry_Green said:
I pointed out some mud and "monet" on grassy trees, and Jack nearly slapped me for pixel-peeping. Because I guarantee you, nobody but me would ever notice it. It's a beautiful wide-angle overhead booming crane shot, with an ambulance and three police cars and actors and photographers all around, at night, and yeah, there's a little mud in the grass -- but who's looking at that?
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Sorry for going a little off topic but, Barry, are you shooting 1080 or 720 when you talk about minimal mud issues? Thanks!
 
I can see there's more real detail in the GH1 footage (look clearly in the wood cabinet) also the GH1 footage is more saturated which causes color noise, try using less saturated modes a manual iso. If you really want to see the GH1 shine in low light you need a faster lens.

dunca said:
TZ5 zoom video is much shaper and has more resolution as you can see in the example frames.
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1080 95% of the time. 720 was used for slow-mo purposes, or if we knew we were going to be exceeding what 1080 could handle and we thought 720 would convert to 24p well for those particular shots.
 
Barry_Green said:
... It's a beautiful wide-angle overhead booming crane shot, with an ambulance and three police cars and actors and photographers all around, at night ...
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Sounds like fun, Barry!

Question: Just curious how the moving crane shot was monitored during the take? Was the operator able to see the GH1's LCD from the ground/ladder, or was the operator riding in a seat on the crane with the cam, or did you rig up a video tap using another cam aimed at the GH1 LCD, or ?

Again, I'm just curious how this shot was handled.
 
Barry_Green said:
Y
Truthfully, using a good cinematographer, we never really had to stress about it. We just shot and it always looked good. Yes, pixel peeping can reveal faults, but I would be surprised if anyone was to look at our footage and was to then complain about it. The GH1 produces incredible results considering its price tag.
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Barry, when will we get to see anything from this production?

.
 
Hah -- monitoring. Hoo boy, that's a knee-slapper...

Um, we positioned people at various points throughout the move, who had good eyesight, and told 'em to squint up at the tiny LCD that was 15' up in the air...

But yeah, monitoring is a problem. We experimented with ideas like putting a security cam up against the LCD, etc., but in the end we just went with using the articulated LCD to make it appropriately viewable from the angles we needed, and practiced the shot a dozen times.

My backup idea was to have been to mount a minicam like an HV20 or something onto the shoe of the GH1 and set them to equivalent fields of view, and run the monitor cable off of the HV20. But a) we didn't have an HV20 on hand, or anything like it, and b) no little cam like that is going to be able to match the 14mm FOV of the GH1, at least not without a wide-angle lens adapter.

But seriously, the lack of live monitoring is quite inconvenient. And so is the lack of a headphone jack. Two gripes that became more annoying as the shoot wore on. You just have to keep chanting the mantra "it's only $1500... it's only $1500... and it almost looks like a Red One shot this... (okay, wishful thinking, but it's only $1500...)" to get past those gripes.
 
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