Grainy mid-range shadows

[nitrospectide]

I am new to the DSLR filmmaking thing, though in years past I shot a fair bit of DV, and before that some 16mm film.

 

I am testing out my workflow with my T2i, and I noticed that I am getting a lot of dancing grain in the mid-range shadows. I had read that keeping at or under 1600 ISO on this camera should produce a clean image, and this was shot at 800. How do I get a shot with shadows that don't fill up with grain? I've seen plenty of others get a nice cinematic look with plenty of shadows.

 

This is a clip that was shot at 1080p and was pulled into Premiere, snipped, and re-exported at 1080p using H.264. The grain looks just slightly more visible than in the original.

 

At issue is the shadowed beige wall in the background:

 

http://download.hexatrope.com/Lisa_Test.mp4

 

[peederj]

Learn & use Neat Video. It's worth the $99 and the overnight rendering time.

[jgharding]

+1 Neat Video. Download the demo first. I run everything shot on 550D/600D through it.

[nitrospectide]

I will definitely check that out. I'd like to shoot the best footage I can in camera though, and wonder why this is happening. What are the issues at work here causing this? Do I just have to drop to a lower ISO to make the grain go away, or is it something else about the shot that is making it do this? Maybe shadows need to go darker and I have to just avoid mid-tone shadows? I'm not sure.

[tosvus]

First off, embrace the grain in the original footage. Use settings in-camera that are as flat as possible (saturation, sharpness, noise reduction), and do the necessary corrections in post. I'm sure you can get excellent footage out of this camera. 

[tosvus]

ps: there is a program being developed called windmotion (google it) that is good at fixing footage. You can check if the program has been optimized to work with your camera. If not, you may try to get in touch with the developer, provide samples and he will likely do so.

[peederj]

Grain is a good thing but there is good grain and bad grain. Good grain is largely monochromatic and even, bad grain has a lot of chroma noise and compression artifacting from chroma subsampling and macroblocking. With Neat you can take away the bad grain and then add good grain such as your favorite film scans (Cinegrain being the best but pricey, Film Convert being very nice and fine, and others such as rgrain and Gorilla grain being better than nothing and useful in spots) and/or controlled fine dither noise to break up the blocks and bands.

 

There is no reason to desaturate your shadows and crush your blacks just to fight noise now that good noise reduction is affordable. If you like the look of those simple measures go ahead but I find it worth the chore to pull noise out as the first order of business once I know what clips I'm using. I bake in NR as part of transcoding, doing my rough cuts with native capture.

[nitrospectide]

tosvus: I will look into windmotion. Thanks for all the feedback.

[nitrospectide]

peederj: You raise another good thing for me to ask about - what are you transcoding to/with? I have not settled on that yet.

[peederj]

My workflow as of now is to cut in FCPX. I cut with the native capture, whatever that is, and then I take the clips I'm using and bake in Neat Video exporting each to ProRes 422 ("Master file"). I replace the original clips with the Neat ones (sometimes I will bake in "handles" in case I want to tighten up edits later) and can then finish off the rest of post very efficiently without having to wait for the NR to work on every frame.

 

If they could make an NR system as good as Neat that ran realtime...perhaps on the new Mac Pro with the dual GPUs...my life would be a lot easier. My current fastest setup just does 7fps with a temporal window of 1...less than a third of realtime. A specific batch processor for Neat would be great too, define profiles and presets for a large number of clips and send it off running. What I used to do was just turn it on at the very end but I find it's better to bake it in in the transcoding process overnight and then you can enjoy its benefits throughout grading and VFX and the like without any further delay. Cutting with the native capture is no problem in FCPX, there's no need to transcode for that step and this way I waste no time or processing on clips I'm not going to end up using. Any project that works will have to be changed, and I only want to spend the time noise reducing an entire sequence once, while I sleep. If I have to do quick touchup NR on newly exposed areas fair enough.

 

Personally I find Neat adds a good $10K to the image quality of any camera for $99. It does not clamp color but allows super whites/blacks. As long as your exposure and white balances are anywhere near the ballpark, and you avoid moire, using Neat plus good grain/dither can fool a lot of people. Another trick I use is luma-specific sharpening after any scaling/repo and before the grain...you want to blur and break up the chroma subsample artifacts, not accentuate them, but maximize luma detail. Bad moire however is just bad...try to get away from moire cameras, and failing that, moire camera placements. Hard to tell when the little LCDs on the cameras moire on their own, but use zoom assist religiously.

[nitrospectide]

peederj: Wow. That was tremendously helpful. I think it will take a me a little time to unpack and research/try all of that. Greatly appreciated!