Advanced Video Editing


Canon EOS C100


Recording and Getting the Exposure Right



To Record

Use the red START/STOP button on the grip to start recording. Press again to stop.  Another START/STOP button is located on the XLR handle unit and at the front of the camera below the lens.






Exposure

First, a word about using automatic exposure - don't. Seriously, if all you do is use the camera's automatic features, then you're undermining your craft. Naturally there are times when you need automatic exposure, such as when you are moving quickly between different lighting conditions. But shooting in auto-mode should be a rare thing. Leaving the camera in auto-exposure will leave signs of what is called "iris breathing" where the camera is continually adjusting the exposure in mid-shoot. Evidence of iris breathing is the hallmark of the unsophisticated shooter and will cause numerous problems in post-production. 

Instead, take control of your craft. Learn how to adjust the exposure manually. 

To set the exposure manually, remember this sequence:

Gain

ND filter

Shutter Speed

Aperture


Gain

Under low light conditions, you can brighten an image by adjusting the Canon C100's ISO/Gain. ISO is a term used more prominently in digital photography that expresses the sensitivity of the image sensor. The higher the ISO the more sensitive the sensor. However, in digital video, we simply refer to this as Gain, which has nothing to do with allowing more light to enter the lens. Gain is used under low-light conditions. But with greater sensitivity comes a price: increased sensitivity generates more noise or graininess in the image. It's just like turning up the volume in your stereo speakers... too much and the audio sounds distorted. 

Sometimes the graininess that appears with more noise might serve the mood of the story, but it's mostly undesirable and even distracting. 




As shown here, the ISO/Gain is a button that will highlight the Gain value in the viewfinder.

To change the Gain value, press the ISO button. This will highlight the current Gain value seen in the viewfinder.









The Gain value appears in decibel units (dB). In the viewfinder, you can see the Gain value in the lower left.

0.0dB – there is no gain. Use this setting when lighting conditions are adequate.

Use the joystick clicking it up or down to change the Gain. Pressing the joystick will set the value.









The range of Gain values are -6dB to 30dB. The higher the Gain value, the brighter the picture, but never apply Gain unless you have to. Don’t rely on Gain for setting the exposure. Use Gain only after you allow as much light to enter the lens as possible. For best practice, start with the Gain off (0.0dB) and then set the ND filter, Shutter Speed and Aperture. 


Shutter Speed

The Shutter Speed is most useful when you are shooting fast motion, such as sports events. Shutter Speed is really a measurement of how long the camera allows light to enter the aperture. A shutter speed of 1/60 means that light enters 1/60th of a second; a faster shutter speed of 1/500 means that it takes light 1/500th of a second to enter. 

Therefore, the higher the shutter speed, the faster the camera is opening and closer the shutter.


Also, the faster shutter speeds have a way to stopping action. A great example is when you shoot a helicopter in flight. Setting a fast shutter speed effectively slows down the rotors to the point where you can actually see the individual rotors. In other words, if you want to avoid the fast motion in the image looking blurred, then set for a higher shutter speed; you’ll get sharper images of fast motion if you set the shutter speed to something higher.

When you increase the shutter speed, you'll notice that it also reduces the amount of light that enters the lens. Therefore, if you want to use fast shutter speeds, you’re going to need more light on the subject. So before you adjust the aperture to allow more light into the lens, it’s important to check the Shutter Speed first. Below are recommended settings for Shutter Speed depending on the lighting conditions:

Indoors – 1/60

Outdoors under sunny skies – 1/100

This is just for starts.


When the Shutter Speed is set lower than 1/60:

In places with insufficient lighting, you could set the Shutter Speed to a lower value (less than 1/60th of a second) to brighten the image. But a speed less than 1/60 will cause you problems with motion blur. A really low shutter speed might produce afterimages that trail your subject when they’re in motion. This image quality is not acceptable in standard professional broadcast unless you’re deliberately trying to add this effect. Otherwise, never use anything lower than 1/60 when are shooting in low light. Try to bring in more lighting.


To adjust the Shutter Speed

Press the Shutter button on the camera as shown, which will highlight the current value seen in the viewfinder

Use the joystick to adjust the value. Note that as the shutter speed increases the picture gets darker.

Press the joystick to set the new value.


 

ND (Neutral Density) Filter

Depending on the lighting conditions you will need to adjust the ND (Neutral Density) filter within an appropriate range when recording in bright surroundings.

Remember, the ND filter is like a pair of sunglasses for the camera – it helps reduce the intensity of bright light. 


The ND filter is operating using a dial as shown. Turn the dial up to the + and the ND filter will change in the following order:

 

ND1 – 2 stops

ND2 – 4 stops

ND3 – 6 stops

ND filter off

Turning the dial in the reverse direction, or -, will change the settings in the reverse order.




 


The ND value appears in the viewfinder. When you don’t see the ND value, then the ND filter is off.

Depending on the lighting conditions, the colour may change when you change the ND filter. Set the white balance again when you change ND settings. 




Aperture

The brightness of the image and its depth of field can be changed by adjusting the aperture, which is strictly the hole in the lens that permits light to enter. The amount of light that enters the lens determines the f/stop value. An f/stop that is large indicates a small aperture size, and less light can enter; an f/stop value that is small indicates a wider aperture size, and more light can enter.

Also, using a larger f/stop value (smaller aperture) increases the depth of field – meaning more of the subject is in focus. A small f/stop value (larger aperture size) renders a more shallow depth of field, meaning the subject may be nicely in focus, but the background is a soft blur.

What you’re really doing to change the size of the aperture is adjusting the Iris, which is a diaphragm that covers the aperture.

The Canon C-100 can automatically set the aperture or it can be set manually to give the user more control over the quality of the image. By default, the camera is set to Manual mode. 


Using Automatic Aperture

In MENU, open CAMERA SETUP > IRIS > MODE > change to AUTOMATIC











Manual Aperture

Simply use the control dial as shown to change the f/stop values

Turn the control dial to the desired aperture. 











In the viewfinder, use the Exposure Bar as a reference. The midpoint of the bar indicates optimal exposure. The indicator inside the bar tells you the current exposure. The negative side of the bar shows less light entering the aperture; the positive side shows more light is entering. When the difference between current and optimal exposure is large you may have either an underexposed or an overexposed image.












Momentary Automatic Aperture

Press the PUSH AUTO IRIS button as shown to temporarily apply automatic aperture. Ideally, leave the camera in Manual Aperture mode so you can adjust the exposure yourself. You can then use the PUSH AUTO IRIS to allow the camcorder to take control of the aperture and then compare the difference between what your manual setting and what the camera sets.







 

Zebra Pattern Feature

The Zebra Pattern can be selected with a simple press of the Zebra button.






















The Zebra Pattern Feature shows black and white stripes over the image to indicate areas that are overexposed.The pattern is displayed only in the viewfinder and isn't recorded into the image.