Advanced Video Editing

Canon XF300

Adjusting the Aperture


The aperture is the opening of the lens itself whose size is determined by adjusting the iris, which is a diaphragm that opens and closes the aperture. The more you open the aperture, the more light enters the lens and the brighter the image. 

The aperture value is described by f-stops, which has an inverse relationship with the size of the aperture: the larger the f-stop, the smaller the aperture; the smaller the f-stop, the larger the aperture

Depth of Field

You can change the depth of field using the aperture. The depth of field increases (greater) when the aperture is smaller, decreases (shallower) when the aperture is larger. 

The aperture in the Canon XF300 can be set to automatic or adjusted manually, which gives you more control over the image. 

Automatic Aperture Control 

The aperture is set automatically based on the brightness of the subject. 

  • Set the IRIS switch to A - the A icon appears in the viewfinder next to the aperture value
When the camera is set to Full Auto mode, the aperture is controlled automatically.

Manual Aperture Control

  • Set the IRIS switch to M
  • Adjust the aperture by turning the iris ring on the lens
  • The f-stop number will be displayed in the viewfinder screen in 1/4 stop increments
When the aperture and gain are set to manual and the shutter speed is not set to auto, the exposure bar will appear on the viewfinder screen. You can use the exposure bar to determine the optimal exposure settings. If the pointer moves towards the negative (-) side of the exposure bar, the image is underexposed. Keep the pointer near the middle of the bar for a properly exposed image. 

When you set the aperture manually and then switch to automatic iris or full auto and then back to manual, the camera will not retain your original setting. 

When you set the aperture value and then switch the ND filter setting, the picture may become dark. Set the ND filter first to achieve a greater range of exposure values.

The iris ring is the last ring (on the right) 

      Push Auto Iris

The PUSH AUTO IRIS button is a useful feature when you want to compare your manual settings with what the camera determines is proper exposure. 

  • Make sure to set the IRIS switch to M
  • Press and hold the PUSH AUTO IRIS button. The camcorder will automatically adjust the aperture to achieve optimal exposure. 
  • Release the button and the camcorder returns to manual aperture control. 
The aperture value set by the camera will override any value that is set manually.

Zebra Patterns

The zebra patterns (black and white diagonal stripes) help identify areas in the image that are overexposed. The pattern only appears in the viewfinder and is not recorded onto the image. 

Press the ZEBRA button to display the patterns. 

You can change the type of pattern in the menu under LCD/VF Setup and then select Zebra.