Noise Freak Out

[Kyle McConaghy]

So I was testing out some picture profiles today at 3db. For some reason, I got DSLR 1200 ISO-type noise. I've never had this before. I have no idea what happened. Has anyone else encountered this? The clip below shows ungraded footage at 100% and 400%.



Thanks for your help!
Kyle

[danstone]

Yeah, I've run into that a few times when using higher gain while over cranking with the FS. It happens mostly in softer areas like skin tones. Looks like the subject's skin is crawling. Though the sensor is super sensitive and clean in the dark areas, you should still avoid using gain unless you absolutely have to. In certain situations the grain structure doesn't play well with the compression.

Some things you have to get used to with this camera:
1. bring along a good monitor to look for anomalies (because you'll hate yourself in post if you don't)
2. plan for some time before each shot diagnosing said anomalies and finding workarounds

This is one of the things we show our clients when they ask, "why pay more to shoot with a better camera?" We joke: because it takes 30 minutes to light a scene, 2 minutes to dial it in and 3 hours to figure out why there's a weird reflection or noise that's ruining your shot.

[Kyle McConaghy]

Thanks, danstone! Have you noticed any specific settings that add to the noise (Gamma settings, Color depth, etc). I was shocked b/c i was only at +3db. I've never seen visible noise pre-grade anywhere below +12. I used CPF - Log for the first time, but no one else has noted any noise issues.

[Alpern]

Have you tried doing a black balance?

[stancemedia]

Thanks, danstone! Have you noticed any specific settings that add to the noise (Gamma settings, Color depth, etc). I was shocked b/c i was only at +3db. I've never seen visible noise pre-grade anywhere below +12. I used CPF - Log for the first time, but no one else has noted any noise issues.

Did you use the LUT for exposure? If you used only the Log then
you basically just underexposed the shot.

Use a standard profile and recheck your noise issue. I'm pretty sure
you were just really peaking into the shadows.

[Kyle McConaghy]

Thanks, all. I did black balance. And, i feel, those shots don't look underexposed enough to warrant the extra noise... but there could have just been some weird anomaly. I'll keep testing! Thanks so much.

[Postmaster]

While at it, can you shoot the same scene with 9db or 15db?

Sometimes higher ISO is cleaner.

Frank

[mraaron895]

It really depends on your picture profile. I spent a few hours yesterday tweaking picture profiles for my FS100 and found that alot of them produce horrible noise in shadowed areas. I found that the ABNorm PP from Able Cine found here http://blog.abelcine.com/2011/07/25/...from-abelcine/ totally eliminated any shadow noise in all of my shots (at low gain settings of course).

[danstone]

I agree that some picture profiles make it worse but I think that ultimately its just a weakness of how the grain structure and the compression play together. You'll notice that you don't see it in your monitor (on-board or external), only when you watch it back later. You'll also notice that it affects your mid-tones while your blacks are still super clean.

For some reason that skin-tonish region of light and color is incredibly rough on cameras that highly compress the footage. The 7D has a hard time with this, too, except it makes those tones horribly blocky. The best way to avoid it is to plan ahead. Bring a good monitor on set with you; record a quick sample, play back, and change your lighting or picture profile if needed. It's a PIA, I know, but the alternative is shooting with a different camera. I'm also willing to bet that this doesn't show up when using an external recorder.

I don't use the camera a lot in a professional setting anymore (too much of a pain) so I haven't had a chance to test specifics. I'm just deducting and guessing with these solutions.