First Year Lessons: Shutter Speed

Shutter speed affects a moving image just as much as a still. When shooting video with a DSLR camera, I am forgetting how the same basic principles that go into exposing a photograph are also critical to apply when exposing a frame in cinema.

Adrian J. Miller & Alex Herod on set. Photo by Myles Herod
Once upon a time, I thought all there was to DSLR video was tinkering with the Av and Tv dials on the camera. Clicking away to expose my subject just enough for my taste. In this practice; the settings for aperture, shutter speed and ISO are only manipulating and compensating for available light levels.
I mean after all, I’m not looking to snap crisp any action shot as I was producing moving and dynamic video. Not photography.
I Know Better Now
I’d like to share my eureka and teachable moment.
I want to tell you about the foundations of exposure and what’s technically involved in achieving a composition – simply illustrated below as The Exposure Triangle.

The Exposure Triangle
Aperture, Shutter Speed and ISO are the basis of The Exposure Triangle.
The values of each section of the triangle will vary depending on what and where you are looking to shoot. But to compose any image with a specific exposure – you have to take all three components into consideration. Although I am familiar with this concept – It does not apply only to still photography.
My old idea of what shutter speed is has nothing to do with DSLR video. As far as I knew, the frame in the viewfinder was getting brighter or darker depending on the lengths of a second I was setting the shutter at.
Until I saw this:

f1.4 1/750ths at 1600 ISO
When installing a hard drive I noted how the fan looked in the viewfinder and rolled on some video. Feeling the image to be too dark – I played with the Av and Tv dials and saw this:

f6.4 1/390ths at 1600 ISO
I rolled on the fan in the first place because I could see the blades – even though to my eyes, they were a blur. When I adjusted the aperture and shutter settings to achieve a similar exposure level with the same ISO – the fan blades blurred much like I was actually seeing them.
Adjusting the ISO and light available to maintain the exposure, and play with the other settings again gave me this result:

f3.4 1/190ths at 3200 ISO
My general conclusion is that the closer the shutter setting gets to one second – the more blur the fan has. That’s a longer shutter speed. A faster shutter like shown in the first shot with a 1/750ths setting yields a sharper fan. We can see it turn at a leisurely pace.
Shutter Speed is Important
I’m astonished at how I had forgotten such basic principles of photography. They would no doubt be the same principles of cinematography.
I feel silly because I am familiar with how cranking the camera and using varying shutter speeds is in countless features I adore – but I had never seen it so personally and so practically until the day I added a hard drive to my computer and turned my camera on it.
The lesson here is to remember there is always so much more to learn about your craft. The goal now is to apply this knowledge and study further how it can be applied to our work.
I wonder what happens when I start to play with the aperture settings…