Why is my video so noisy?

E

edee1337

New member
Hello! First time poster, long time reader here. I finally got around to installing the hacked firmware on my GH1 today, and I set up a little test to see how much I will be benefiting from the extra bandwidth. I used lpowell's 40Mbps AVCHD reliable patch, and away I went.

On first look at the footage, I actually couldn't tell the difference between the hacked and unhacked videos. To be honest, both looked crappy to me and I can't figure out why. But that's for another post, I need to run a few more tests tomorrow...

One thing I can complain about, however, is how much artifacts there appears in my test. Please look at the footage, specifically the bottom middle of the frame on the back of the chair that's facing away from the camera. Is this normal, even at ISO 100? Something doesn't seem right to me, and it's really getting on my nerves.

The footage on vimeo and my uncompressed footage look practically identical. I shot this at f2.0 with the 20mm pancake, focus is on the center of the frame with the following settings:

720p60
-2, 0, 0, 0
Smooth

On my old, half-broken giant LCD, the noise isn't that apparent, but on my laptops display, it's all I can focus on. Is this much artifacting normal for a GH1?

Thanks for your help.

 
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an important question here is what shutter were you shooting at? i may have speed read but i don't think you mentioned it. and when you mean noisy do you mean alot of artifacts?
 
yeah my bad, I guess I misused the word noise....I definitely meant artifacts, I should change the title. It looks pretty nasty to me, but this is the first time I've really scrutinized my footage from my GH1, so I'm not sure if it's been there all along.

For ISO 100 I had to use a pretty slow shutter speed, I think I had to dip below 1/30, probably 1/25 or 1/20. And for the rest, just doubled. So probably ISO 200 was 1/50, ISO 400 (I actually think that one was 1/80), etc..

hmm, doesn't seem to let me change the title... sorry, I'm a stupid noob :(
 
Couple of observations:

With a hacked GH1, you want to be shooting video in Creative Movie mode (the one on the dial with a movie camera icon and a capital P), with Manual exposure settings chosen in the settings menu under the Video tab.

If you're shooting 30p, lock your shutter speed to 1/60 (just plain 60 on the on-screen menu). Never set shutter speed to below video frame rate. Doing so plunges the bitrate, and a starved codec = noise/mud/despair.

When I have to shoot in a low light setting like yours, I know going in it's not going to look as great as well-lit video. That's just something you have you accept. But there are things you can do to minimize noise:

1. Up your ISO to 200, and if that doesn't get you acceptable exposure, go to 400. Above that is a crapshoot, some GH1s seem to do really well in this regard, others look worse than my GF13. But certainly ISO 100 in a darkly lit room like yours is a non-starter.

2. if you can't get acceptable exposure with ISO 400, drop your shutter speed to 1/30 (30 on your LCD menu). There will be more motion blur on fast moving subjects but it's often an acceptable tradeoff for the added light which cleans up the video noticeably.

3. Instead of doing what most newbies do (myself included) which is flail around with different settings until something works ok, set aside some time and run some comparison tests to see what settings work for you. Shoot the same scene at ISO 100 1/60, ISO 100 1/30, ISO 200 1/60, ISO 200 1/30, etc. Narrate each setting at the beginning of each 20 second clip, then dump the clips into your editor and watch them as one continuous sequence. If you're curious about the different camera modes for video, try doing a comparison of clips shot in Creative Movie mode and then Aperture priority, Shutter priority, etc. At the beginning of the hackscapades there were some who felt Shutter priority plus AE lock was the best way to shoot clean video on these cameras. Others feel Creative Movie mode is best, with the hack in place to allow for fully manual control of shutter speed et al. The only way to know which you prefer is to do an apples to apples comparison, with your camera.

4. It is critically, redundantly imperative to calibrate your monitors if you are judging things like video noise, which can be hugely exaggerated by the typical consumer LCD screen setting of maximum contrast and brightness. For a flat-panel TV, a calibration DVD like AVIA or even just the short THX Calibrator found in the setup menu of recent Pixar DVDs will get you most of the way there. Laptops can also use these DVDs, or the built-in calibration tools in their preference menus. None of this is as comprehensive as a real professional calibration but it's a lot better than nothing and gets you a lot closer to seeing what your footage actually looks like when not artificially boosted by the marketing decisions of consumer electronics manufacturers looking to wow the proletariat in the aisles of Walmart.

5. Easiest tip of all: if you're shooting critically, don't shoot video in dark indoor settings without throwing up some extra light. Even with the hack, these cameras aren't miracle workers. They need light to be happy. Give them light. Forget about underexposing and all that nonsense if you're shooting a room like this. The room is forcing underexposure on you already. What you want is the opposite -- more light, better exposure, cleaner video.
 
thank you very much for your responses! I'll have to run some more tests tonight. But I have to say, even at ISO 400 (where I'm positive the shutter speed was at least 1/80), I can still see that really bad artifacting. But I'm guessing it's something that's unavoidable. I'll try a variety of ISOs, shutter speeds, etc., and try to add more light, and see how it turns out. I'm also really disappointed with the video quality, but I'll make another post about that after some more tests. I've been reading this forum for quite a while and I dunno...maybe I was expecting too much.

Thanks again for your help.
 
First of all, go to Manual stills mode (capital letter M) and in the menu activate the ISO 1/3 stops. Seems like you don't have it activated.

I think the GH1 is great until ISO 500, even acceptable at ISO 640, but I dislike ISO 800 and as you can notice, ISO 1600 totally drops the ball.

Tone everything down to -2, but not saturation, you can't add saturation back, but throwing away is easy. NR makes the underexposed areas blotchy, muddy, so also tone NR down to -2.

And well, don't expect noise free image, it's a GH1 not a R1 M-X.
 
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