Falling Snow & Shutter Speed

The March lesson is on Motion – the key camera setting we’ll consider is shutter speed. As I look out the window at the start of our major snowstorm, I see a great learning experience in preparation for this upcoming lesson (even though it’s a month away).
Get out your camera and go to a window (get close & try to avoid reflections) –

  1. Set your camera’s shooting mode to Shutter Priority
  2. Choose a slow shutter speed like 1/2 second (how slow you can get depends on the light/camera/lens)
  3. Make a photo of the falling snow
  4. Halve the previous shutter speed (in this case from 1/2 to 1/4)
  5. Shoot again
  6. Halve the shutter speed again (1/4 to 1/8)
  7. Shoot again
  8. And so on, and so on… until the shutter speed is around 1/250 or 1/500 (how fast you can get depends on the light/camera/lens)

Now look at each of the resulting photos and notice how the falling snow is rendered as the shutter speed changes.
Which speed should you use? The one that you want. The one that renders the falling snow in the way that reflects the story you want to tell with your image. It won’t always be the same story and thus won’t always be the same speed. Keep in mind which speed ranges do what and you’ll be prepared in the future.
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Here is a series made a few minutes ago.

Near top center of the examples’ page you’ll see 1 of 9 Next>
Click on Next> to progress from slow to fast. A caption beneath each image shows shutter speed, aperture and ISO.

  • Note that anything slower than 1/125 results in snow flakes rendered as streaks.
    • The only difference is the length of the streak (a creative decision).
  • Above 1/250  freezes the flakes.
    • In this fast range you have to be conscious of DOF (month one’s lesson).
      • If you’re using a fairly wide angle lens (say 25 mm or less) and shooting the HH oak from a distance of 100′ or more, the the flakes will render as streaks or flakes as decided purely by your shutter speed (think hyperfocal distance) and DOF isn’t an issue.
      • However, if you’re using a longer lens and/or the subject is close then at wide apertures (certainly the case for 2.8 – 4.0) the shallow DOF will render the flakes within the DOF sharply and the others will appear as white orbs of varying sizes.
      • Wide apertures will occur as you try for faster shutter speeds.
      • This combination of flakes and orbs is also a creative choice. A key point though is that there’s a difference between a creative choice (done on purpose) as opposed to a “happy accident” (you like what happened but have no idea of how you did it and can’t repeat it).
  • In my series I used a 50-135 mm lens at 50 mm.
  • Matrix metering and EV=-1 to compensate for the large black grill that the camera wanted to lighten to middle gray.
  • The grill (my black background so the flakes would stand out) was 15 feet away and I manually focused at about 11 feet.
  • At f/2.8 (fast shutter speeds) the DOF was a little over 1 foot. At these speeds, the snowflakes falling near to the window produced the orbs.

Russ, note what happens using shutter priority as I get to f/2.8 (the widest the lens can open – which occurred at 1/125). The camera (not me) recognizes that it’s in shutter priority and must produce the shutter speed that I request. Since it can’t open the aperture any further (which is its first choice in compensating for my dialing in a faster shutter speed of 1/500 after the aperture reaches f/2.8) – what does it do? It raises ISO. Hopefully, this ISO business is starting to make sense. Yes?

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