A Comparison of Noise Reduction Techniques for Log footage

If you don’t follow the wolfcrow system, you will end up with noise. If you underexpose, you will find yourself frustrated by the quality of your images. In this article and video we’ll go over the noise reduction options in Adobe After Effects, Photoshop and Adobe Premiere Pro (via Neat Video).

Noise reduction

What are we looking for? Which method offers:

  • The best noise reduction without a major loss in detail (resolution)?
  • The best preservation of edge contrast (acutance) without the introduction of additional noise or loss in resolution?
  • Better chroma noise reduction?
  • The least amount of additional sharpening required?
  • The fastest turnarounds in terms of CPU/GPU usage, and
  • The fastest workflows for busy editors and colorists?
  • Best return on investment.

The softwares I wanted to add to this comparison, but didn’t, are: Speedgrade (poor noise reduction, already tested earlier in another video), Davinci Resolve Studio (I don’t own it, and Lite does not have NR), and Digital Vision DVO Grain (arguably the best noise reduction plugin available, but expensive).

Noise reduction methods

All noise reduction algorithms work similarly. The basic steps are:

  • Create a noise profile from the footage.
  • Apply noise reduction – global, luma-only, chroma-only, channel-wise, temporal, etc. This varies vastly from algorithm to algorithm.
  • Tweak according to taste – there’s a lot of subjectivity when it comes to noise. Many people like film-like grain. I hate it!
  • Re-introduce detail by sharpening, etc.

Should you color grade before noise reduction or after?

Based on what I know about image processing, I’d go for after. Not because it is fundamentally better (it isn’t), it’s because if you make a mistake and discover noise while grading, you’d have to do it again. However, there is also a strong case for applying noise reduction prior to grading, for two reasonable reasons:

  • Preparation of footage beforehand so you can work in realtime with demanding clients. Noise reduction really brings even high-end heavy iron systems to their knees.
  • More accurate colors because you will get rid of color casts caused by chroma noise, etc., before you grade. It’s a ‘visual’ thing.

Finally, what’s the best way to get the least noise? Avoid it when you shoot! Of course, that’s not an option for an editor or colorist. You must work with what you get.

Comparison of noise reduction techniques for log footage

The tools I’ve used for this comparison are:

  • Remove grain + Extract in Adobe After Effects
  • Adobe Camera RAW (ACR) in Adobe Photoshop
  • Neat Video + Extract (if required) in Adobe Premiere Pro

I’m aware of other plugins that compete with Neat Video, and I’m sure they do well under certain situations. I will test them individually later, this video is long enough as it is!

Here’s my humble comparison:

Notes:

  • Via the wolfcrow system, we know anything below 40 IRE will have noise by default (only true of S-Log2 shot on the a7S, a7S II and a7R II). This is why we use Extract, to isolate only those regions that need noise reduction. The same methodology can be applied to other sensors, but the numbers will change.
  • The 40 IRE rule does not take into account the noise introduced by high ISOs, which is different. But then again, that noise is all over the image, so masking isn’t going to help much. This is what we’ve done in the third clip, shot at 51K ISO or higher.
  • I don’t think you can load ACR in After Effects with video footage, but I could be wrong.
  • Neat Video is GPU accelerated. I’ve used version 4 for this demo. You can also get this plugin for After Effects, Resolve, Scratch, Mistika and others. Check their website for details.

Conclusion and takeaways

Here’s a chart that puts things in perspective:

Feature Remove Grain/AE ACR/Photoshop Neat Video
Luma noise reduction Not potent enough Not bad Excellent
Contrast and sharpness Good Excellent Excellent
Color noise reduction Unacceptable Excellent Excellent
Need for additional sharpening Not much Yes Sometimes
Computer usage Very poor Very good Excellent
Workflow for complex projects Passable Poor Excellent
Price Free Free Worth it

The bottom line is there’s nothing like Neat Video for the Sony a7S II, a7R II and a7S, which is also affordable. I’m aware of other plugins that claim to come close, and I’m sure they do well under certain situations. But Neat Video has been around for a long time and is very stable, fast and ubiquitous in most post houses. It’s a secret weapon. You (or your clients) either seriously need noise reduction or you don’t. If you do, Neat Video it is.

Look, I didn’t start out this comparison to extoll Neat Video (to be honest I was hoping I could do a good job with Remove Grain, and this is the first time I’ve ever used Neat Video), but I can’t deny the results. It’s drastically superior to the others.

I’m probably going to pick up a license soon, but first I will evaluate its competitors, and will publish my results in my guide. Is there anything better than Neat Video? Yes, DVO Grain by Digital Vision is the undisputed king of the noise reduction world, but I don’t have first hand experience with it.