Exposure Lab

While the aperture impacts the amount of light hitting the camera sensor (and therefore the exposure), filmmakers set the aperture based on what they want the depth of field to be.

Do you want a shallow depth of field? With only a little sliver in focus and a lot blurred out in the foreground/background? This can help isolate/focus on your subject.
Or do you want a large depth of field? So you can see all the details in the shot whether they are close or far away?

A Guide to Video Camera Aperture | Artlist

#3 Test Out Different F-Stops

With the Canon T3i + 18-55mm lens (or similar set-up), set to 1920/24, and zoomed out (18mm):

Set your Shutter Speed to 1/50
Set your ISO to 800
Wind up your toy and take 3 different 2-3 second clips:
- Aperture: f/3.5 (lens must be at 18mm zoom)
- Aperture: f/8
- Aperture: f/22

#4 Shutter Speed (Motion Blur)

While the shutter speed impacts the amount of light hitting the camera sensor (and therefore the exposure), filmmakers set the shutter speed based on how much motion blur they want in their video.

The most common and natural-looking amount of motion blur is to set your shutter speed to double your frame rate (ex: 24 fps would be 1/48 (aka 1/50) shutter speed)
Reducing the shutter speed creates blurrier, hazier, and smoother motion
Increasing the shutter speed creates crisper, more intense, frenzied, and choppy motion

Learn more on the Vimeo blog: Understanding frame rate vs. shutter speed

#5 Test Out Different Shutter Speeds

With the Canon T3i + 18-55mm lens (or similar set-up), set to 1920/24, and zoomed out (18mm):

Set your aperture to f/3.5
Set your ISO to 800
Wind up your toy and take 3 different 2-3 second clips:
- Shutter Speed: 1/10 (blurry)
- Shutter Speed: 1/50 (natural)
- Shutter Speed: 1/4000 (jittery)

#6 Measuring Exposure

Standard exposure allows your viewer to see all the detail (highlights and shadows).

The camera's light meter or metering sensor will show your exposure
- Negative number: underexposed
- Zero/center: standard exposure
- Positive number: overexposed

Once you have set your aperture and shutter speed based on how you want your video to look, you'll need to make sure your exposure is correct. You can do the following:

Adjust your ISO
Add an ND filter (sunglasses for your camera)
Add lights

#7 ISO (Light/Noise)

ISO measures the camera sensor's sensitivity to light (and therefore the exposure).

Much like increasing the volume on a static-y radio broadcast, increasing ISO amplifies everything that the sensor sends to the processor, which includes the interference (grain).
Higher ISOs enable you to shoot in darker conditions but will show more of the grain or noise.
In general, you want to shoot with the lowest ISO you can.
Canon T3i suggested ISO: 800

#8 Test Out Different ISO

With the Canon T3i + 18-55mm lens (or similar set-up), set to 1920/24, and zoomed out (18mm):

Set your Shutter Speed to 1/50
Set your aperture to f/3.5
Wind up your toy and take 3 different 2-3 second clips:
- ISO: 100
- ISO: 800
- ISO: 6400

#9 ND Filters (CAmera Sunglasses) & Lights

Often times when filming outside when it's sunny, your set shutter speed and aperture will be allowing in too much light to be properly exposed.

Neutral Density (ND) filters allow you to block light coming into your lens while keeping your settings as is.
There are set and variable (adjustable) ND filter options.

Often times when filming inside, your set shutter speed and aperture won't allow in enough light to be properly exposed. This is where lighting comes into play!

This is a whole other lesson (coming soon!)

Turn In

Turn in your completed Exposure Lab guided notes paper to Mrs. Hodges