Recently, I have been in touch with Noam Kroll, an award winning Los Angeles based filmmaker, and founder of the boutique production company Creative Rebellion. Noam’s blog is a brilliant source for anyone interested in the mechanics of film production & a the place he shares fundamental storytelling techniques that go far beyond the relevance of any single piece of equipment, whether it be in the areas of story, direction, cinematography or otherwise, and has been a really useful source for me.
I found this post about protecting highlights particularly interesting.
What do I mean by protecting the highlights?
Essentially what I’m referring to is the practice of exposing your image for the highlights (or hotspots) in the frame to ensure nothing clips. In a scenario where you have an actor standing in front of a bright window, exposing for the highlights would mean that you bring your exposure down low enough that the window isn’t blown out at all. This technique has become extremely popular amongst filmmakers (especially those from a DSLR background), simply because blown highlights on certain cameras can look absolutely awful, and underexposing is one of the simplest ways to get around it. The only problem is that this approach can often yield results that are just as bad, if not worse than letting those hot spots clip.
In an ideal world, you want every shot that you capture to be perfectly exposed. You don’t want to crush your shadows too much (otherwise you will lose shadow detail), but at the same time you don’t want your highlights to clip unnecessarily either. Unfortunately though, unless you are shooting in an ultra flat lighting situation – chances are either the highlights or the shadows are going to clip. And more often than not (at least for daytime work) it’s the highlights.
Practically any daytime interior or exterior shot that you capture is going to have some bright highlights that may become overexposed. This may be a window, a reflection, a white wall or any other number objects or sources. Even night time shots will have hotspots, usually in the form of bright light sources such as lamps or street lights that are prone to clipping. These types of shots can be a challenge to work around, but there are certainly ways to deal with them and still achieve a nice image… That said, your best bet usually doesn’t involve underexposing your entire shot.
To illustrate this, take a look at these luma scopes below. The first is from a perfectly exposed daytime image:
And the second is from an underexposed daytime shot:
Why underexposing doesn’t work…
As I mentioned above, I do a lot of color grading work and by far the most common issue I encounter are underexposed shots – usually as a result of overprotected highlights. Having to attempt to save this type of underexposed footage time and time again has made me realize that this is a very common issue amongst filmmakers, and certainly one that is worth being addressed here.
The reason why protecting your highlights is a bad idea is quite simple.. You are ignoring the most important parts of your image (and therefore not exposing them properly) so you can retain detail in an unimportant area of the frame. For example, a shot that is exposed to the left (so a desk lamp doesn’t clip) is naturally going to be underexposed across the board. A bright light source like a lamp should probably be the brightest thing in your frame (for a nighttime shot at least), and there is absolutely no reason why we need to see any detail in that lamp. Our eyes don’t even see that way… But by exposing for that lamp, now all of the important parts of the frame (most importantly the actor’s faces) are going to be way underexposed.
Here is a still from my film ‘Footsteps’ where the window is blown out. We made the choice not to expose for the window to ensure our actors faces still retained some detail:
The fundamental issue with underexposing your footage is that in order to be color corrected later, a lot of heavy grading needs to be done… And even then, the final result is never great. The last thing you want to do with most cameras is bring up the shadows and midtones too much or you will start to introduce a lot of noise into your image. Unfortunately though, when attempting to save underexposed footage you really have no other choice. In the end you wind up with a very grainy shot that needs to be heavily de-noised, and that can lead to some very mushy footage.So, what should you be doing?