Over/Underexposure as a Tool: An Experiment

[AJ Young]

I've used this technique before on three projects and loved the results. Essentially, I underexpose the image by a certain number of stops intentionally and then recover it in post for a desired look. This was partially inspired by Martha Marcy May Marlene and Birth, but also inspired by how film responds to light (poor shadow detail in comparison to how much highlight detail film, particularly Vision 3, can handle)

The idea behind this method is to control how the camera's dynamic range is distributed. The general theory with ISO and digital cameras, particularly in RAW, is that changing the ISO doesn't make the sensor more or less sensitive, it just reads the RAW data differently (there are a few exceptions, of course). When a cinematographer deviates from the native ISO, they are under/overexposing the image and the new image has the dynamic range re-mapped by the debayering process. However, I wanted to control how that dynamic range was redistributed. Is this something we can do? Something we can test?

I recently finished an experiment and would love for everyone to check my work, to make sure what I'm experimenting with is actually correct. You can find the detailed (and very nerdy) experiment here: http://www.ajyoungdp.com/articles/blog/OverUnder01/

Here's a tease with all of the over/underexposures from the experiment in one image:

What do you think? What are your thoughts? Am I off base here?

 

[Adrian Jebef]

OK so here are my thoughts...

I like what you're doing. Ya gotta push limits and find the beauty in the edges.

That being said digital is not film. The beauty of film is its logarithmic response. It has a certain falloff on the top and bottom. Even when you purposefully screw around with over and under exposure film can produce pleasing aesthetic results. Not so much with digital. Some digital camera when pushed hard do have a similar but wholly different aesthetic. The old classic arri alexa springs to mind. Want to shoot 1 stop pushed 16mm? Set ISO to 1600-3200 and record ProRes. The biggest issue with digital is underexposure noise. Does the noise appear aesthetically pleasing or does it look awful? That's the rub. Just like with film it's a personal choice. For me an old alexa has organic noise. When pushed I like it. Especially if you want a reversal black and white look. Another digital camera that I loved when pushed was the Grass Valley Viper Filmstream. Badass. Venice? I'm not really into it. Monstro/Gemini? Eh I think there's too many pixels there. But that's just my opinion. If you find something special in your tests by all means pursue it. Pushing the boundries is what we are supposed to do. Good luck.

 

[Adrian Jebef]

BTW I noticed your slate. I like the GH4 when pushed. It's pretty sweet.

 

[AJ Young]

First, thank you for reading it!

OThat being said digital is not film. The beauty of film is its logarithmic response.

I totally agree! One of the key factors for this experiment was shooting in Log.

I did notice that digital noise doesn't behave like film grain when it comes to the highlights. On film, we can still see the grain even in the highlights. On digital, the highlights are CLEAN.