SHOOTING ANAMORPHIC WITH PHANTOM FLEX
Shooting with anamorphic lenses is a technique of capturing a widescreen picture on a standard 35mm sized gate or sensor. This process requires traditional x2 anamorphic lenses, which squeeze the image by a factor of two. Beside the obvious aesthetics differences between spherical and anamorphic lenses, one of the main benefits of shooting anamorphic is the increase in resolution.
Traditional 35mm film cameras have a 1.375:1 gate ratio. In order to achieve the cinematic 2.39:1 widescreen ratio whilst still retaining use of the square format, anamorphic lenses are used to optically compress images as they are filmed. On projection the images are corrected with another optical process.
In the modern film industry anamorphic lenses are still used for their ascetical characteristics. But many digital cameras are now being produced with sensor ratios made to the more commonly required 1.78:1 or 16×9 ratio. Cameras such as the ALEXA and ALEXA Plus cameras, which are capable of 16:9 but not 4:3 sensor mode, do not compliment x2 anamorphic lenses when resolution is concerned.
When using cameras with sensors that are natively 16:9 or even wider, it is necessary to crop the sides, resulting in a much smaller utilised sensor area and a different angle of view for the lens. If resolution and quality is a concern using the 1.3x anamorphic lenses will provide a more efficient use of the sensor’s 16:9 aspect ratio and thus a slightly higher resolution and less noise in the final image. When using the ALEXA M or ALEXA Studio, it is much better to use 4:3 sensor mode when shooting with anamorphic 2x squeeze factor lenses, eliminating the issue of reduced resolution.
Phantom cameras are very different. Their sensor ratios vary between models, most commonly having a ratio of either 1:1 or 1.6:1. Additionally, the pixel ratios of the sensor can be adjusted much more accurately, allowing specific capture ratios to be chosen. This has the benefits of capturing images on a sensor ratio native to x2 anamorphic. Resolution can be retained and stunning slow motion images can be captured.
When shooting with anamorphic lenses, the maximum height of a Phantom camera sensor is utilised, while the left and right is cropped to an Academy ratio as covered by the lens. The Phantom Flex’s 1.6:1 ratio sensor is 16mm in height and does not cover the full height of the lens. Typically the resolution of 1840×1600 is used. This equates to an image area 22% smaller than 35mm film. To maintain the same angle of view as film, the focal length of the lens must be increased by a factor of 1.15.
Comparing these numbers to other cameras and you can see the Phantom Flex is very suited for anamorphic image capture. A Red Epic utilises an image area 33% smaller than film and a 16×9 Alexa recording ProRes has a capture area 44% smaller than 35mm.
The Phantom cameras HDSDI high definition live video feed can easily de-squeeze, allowing for on-set monitoring in the widescreen ratio intended.