The SIRUI Astra 1.33x is a series of anamorphic full-frame auto focus lenses. Previously, we have seen a few companies, such as Blazar and SIRUI, release 1.33x AF anamorphic lenses, but they were only designed to cover S35 sensors.
The SIRUI Astra 1.33x FF Auto Focus Anamorphic Cine Lenses will be available in focal lengths of 50mm, 75mm, and 100mm, all with a T1.8 aperture. Just like the company’s 1.33x S35 AF lenses, they should be available in Sony E, Nikon Z, FUJIFILM X, and Leica L mounts.
The reason behind going with a 1.33x squeeze is for two reasons. The primary one is that it is hard for AF systems to cover wider anamorphic squeeze ratios. The AF works well with a 1.33x squeeze, but anything wider starts to cause issues with AF systems. The second reason for going 1.33x is that it is more suitable for use with 16:9 sensor cameras that don’t have open gate or anamorphic recording modes.
1.33x is less popular than 1.5x, 1.8x, or 2x, as a lot of people feel that it doesn’t produce an image that they would categorize as having a strong anamorphic look.
In a lot of ways, particularly for more affordable anamorphic lenses, the decision to go with a 1.33x anamorphic arguably makes a lot more sense than going with a 1.8x or 2x. I say this because 1.33x is more versatile and it allows the lens to be used on more cameras, although you could make that argument for 1.5x as well. Making a 1.33x anamorphic is also a lot easier than creating a 1.8x or 2x anamorphic, and you don’t have to make as many optical compromises when designing a lens.
1.33x Anamorphic Lenses on any 16:9 sensor camera, regardless of whether it is full frame or S35, make for a more versatile solution.
There isn’t a lot of information about these lenses, as SIRUI is launching them through an upcoming Kickstarter campaign.
