Monitoring the horizontal compression and decompression of anamorphic widescreen lenses

Anamorphic Widescreen Lenses and Desqueeze Monitoring

Anamorphic lenses compress the image horizontally during recording; when monitoring, desqueezing according to the lens factor allows you to check the aspect ratio, but the preview does not change the actual data recorded by the camera. The Panasonic DC-GH6 rear Anamorphic Desqueeze Display offers options of 2.0×, 1.8×, 1.5×, 1.33×, 1.30×, or off, and can display crop marks for the desqueezed view; the manual also states that HDMI output images are not desqueezed. Recording format, aspect ratio, and monitoring aids should be verified separately. [G-ANA-01]

Monitor and Post-Production Software Settings

External monitors may also provide independent desqueeze viewing functions. The Atomos support page lists options for the Ninja V+ of 2× (4:3), 2×, 1.8×, 1.5×, 1.33×, and 1.25×; other devices and firmware should follow their respective manuals. [G-ANA-02]

The DaVinci Resolve 20 Official Colorist Guide project settings examples list pixel aspect ratios such as Square, 16:9 anamorphic, 4:3 standard definition, and Cinemascope. You should first check whether the edited material is still recorded in compressed format, the project pixel aspect ratio, and timeline settings to avoid stretching already desqueezed footage; menu items and output effects should be confirmed according to the current version and delivery spec. [G-ANA-03]

Calculating the Final Aspect Ratio

The desqueezed aspect ratio is determined by the effective width-to-height ratio of the recorded frame, the horizontal desqueeze factor, and any post-crop. Mathematical example: a full 16:9 grid multiplied horizontally by 1.33 results in (16 ÷ 9) × 1.33 ≈ 2.36:1; this does not guarantee 2.39:1, as the actual recorded area, lens factor, and cropping all affect the delivered ratio. [G-ANA-04]