In a new video from The Camera Store, Jordan Drake and Chris Niccolls not only give you a quick rundown of what log video is, but talk about when and how you should shoot in log, and also how to get started with grading those flat images. If you're brand new to log, this ought to be super helpful:
While there are a few obvious bits in this video, like boosting contrast and saturation in order to start your grade (or applying a LUT), there are also some excellent tips on how and why to shoot in log in the first place.
First and foremost is the fact that shooting in log isn't always necessary. Because log is primarily designed to maximize dynamic range, it makes sense to shoot log in tricky lighting conditions where you expect there to be both extremely bright and dark parts in the image. However, in more controlled lighting situations, such as studio work and shooting green screens, shooting in log isn't really accomplishing much for you. In fact, it's just making more unnecessary work for you in post-production.
Second is the issue of noise. Because log curves pull up the shadows, digital noise can often become significantly more noticeable. This can make for some headaches later on, but there's a somewhat simple fix to this. You've probably heard of ETTR, or "Exposing to the Right." Essentially, by exposing a stop or two brighter (of course making sure your highlights aren't completely blown out), then pulling down the exposure in post, you can ensure that your image will have much cleaner shadows.
There's a major caveat here, though. ETTR can be problematic in the context of filmmaking because of the low bit-depth that many cameras record internally. It's much easier to lose highlight information completely when you're not shooting RAW. Add to that the fact that exposing a log image can be tricky, especially if you're trying to do it by eye without some sort of monitoring LUT. All of this is to say that if you plan on using ETTR, be extremely careful. If you don't nail it, you're potentially setting yourself up for re-shoots.
Lastly, low-light shooting and log don't mix particularly well. For a great technical explanation of why this is, check out this post from Alister Chapman. Here's the main gist of it:
You don’t need log when the scene only has a limited dynamic range. If you use Rec-709, which has a 6 stop range (without any knee) instead of log, at the same ISO, then now instead of recording using only 35% of the available data you will be using almost 85% of the available data and that’s going to give you much more real picture information to work with in post production. You will get a much better end result by not using log.
For those of you who have been shooting log for awhile, what do you wish you had known when you were just starting out? Leave your advice down in the comments!
Source: The Camera Store - YouTube