Mosaic Engineering, Inc.

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Blackmagic Design - Ursa Mini 4K & 4.6K

Third-Generation Anti-Aliasing for Ursa Mini 4K & Ursa Mini 4.6K (& Ursa Mini Pro)

Please note our separate page regarding Initial Production and Group Buy Terms for this new filter.

For the Ursa Mini series of Blackmagic cameras, we have developed a new, third generation of optical anti-aliasing filter, with a very high level of performance, and a new level of image quality, beautifully complementing these excellent cameras.

The filter strongly supresses the moiré and aliasing artifacts that these cameras can unpredictably produce when shooting fabrics and other fine textures.  The filter works by removing from the optical image - even before the image arrives at the focal plane - problematic spatial frequencies that the Bayer-pattern image sensor is not able to correctly sample.  This has the additional benefit of eliminating what we have come to call “subliminal aliasing”: an erroneous layer of finely-structured false detail that is created when a raw digital image sensor samples a sharply textured optical image without the benefit of a correctly designed anti-aliasing filter.

The resulting image shot with our filter has a distinctive smooth and clean quality, free of the distracting false textures and subtle sampling errors that the raw unfiltered camera can generate with problematic subject matter.

One early user of this new filter has commented:

“So far I'm blown away by the beauty of the image.  Thanks for fixing me up with this thing, I never want to shoot anything without this filter again.”

“Your filter eliminates the worry about getting a shot so aliased I can't seamlessly clean it up in post.  Also, it creates a creaminess only available with Alexa.  Alexa is the big deal here.  This filter furthers the look of this $5K camera as comparable to the $70K Alexa.”


For an initial demonstration of the filter's optical anti-aliasing performance, please see our introductory video:



The Ursa Mini filter also includes highly effective Infrared Filtration as an integral part of the filter's optical design.


The filter installs behind the camera's inner lens flange bezel, as shown here:

UM-optic-installed.IMG 7538.960x640

Installation is straightforward.  Please note that during the installation process, the camera's built-in, sealed blue-green glass is never disturbed or removed - our filter simply installs in front of this blue-green glass.  The highly clean, factory-sealed environment containing the image sensor is never tampered with or contaminated.


As with all our supplementary optical anti-aliasing filters, the Ursa Mini filter ships with all tools needed for the installation:

IMG 7607.UM-Kit.960x640

As shown, a precision-machined shim set is supplied.  The optical shim compensates for the shift in back focus induced by the insertion of the filter behind the lens.  Therefore all lenses focus normally with the filter, and all zoom lenses track focus normally while zooming, just as they did without the filter.