Examining The Shutter

The shutter is the mechanism the camera uses to open a camera’s sensor or film to light, and close again. Shutters need to be able to achieve very precise timings.

There are two main types of shutters. Focal plane shutters and leaf shutters. Almost all cameras we will interact with these days use a focal plane shutter.

Due to the mechanisms of a focal plane shutter, we can achieve intentional or accidental slit scan effects.

Slit Scans

I recommend taking a deep look into slit scanning before digging into focal plane shutters. There is no better way to do that than with Golan Levin’s cataloge of slit-scan video artworks and research. Spend an afternoon and dig through this massive and wonderful collection of work. Whenever I am feeling uninspired, this is one of my go-to re-reads.

Understanding Shutters and High Speed Sync

Another great read on camera shutters, slit scan effects, and high speed flash in this article by Derek Baird. It expalins the techniques better than I could here, go give it a read.

Why Digital Cameras have Mechanical Shutters

Another good read is this resource on why digital cameras have mechanical shutters.

High Speed Photography

High speed photography deserves an entire section to itself, coming soon.

Long Exposure


How long is long exposure?
Long enough to turn traffic into streaks of light?
Or water into a silky mist?
Shoot a crowded space with long exposure photography and you can make any people (moving) dissapear entirely.
How about long enough to capture the movement of the stars?
How about long enough to capture the sun’s changing path over six months?

by Justin Quinnell. More about this image.

Intentional Motion Blur

There are two main reasons to use motion blur. The first is when you want to show your subject moving a little bit. I shoot college campuses, and I often shoot with a slower shutter. I don’t need to see any students face, and the bit of blur gives a sense of life and action to my images.

The second main reason is when you want to show your subject moving, but capture it sharp. To do this, we move our camera so that the subject – also moving – stays in the same relative place (on our iamge sensor). The background blurs, but the subject stays sharp.

This video does explain the technique.

If you are still confused or tired of reading, here is a second unnecessarily long and needlessly condescending video on the topic.

Zoom Blur

zoom blur

Zooming over the length of the exposure can create an interersting ‘warp speed’ effect, but it is probably best combined with a flash at the beginning or end of the exposure to lock our subject, and them blur them out. See more on that in the section on {%post_link examinations/light-over-time%}.

Focus Blur

Focus Blur is when you change the focus over the course of the exposure. Generally not considered useful unless you are also manipulating the light itself (see the section on {%post_link examinations/light-over-time%}), some photographers did discover it’ can produce amazing fireworks images.


I consider focus blur to be an extremely under-explored technique. What can you do with it?