If the name NiSi Optics rings a bell, it's because it's known more for its filters than lenses. However, it did announce a set of primes back in 2018 at NAB. Now it has unveiled a full frame, very wide 15mm F/4 lens called the NiSi Sunstar, which is for a nice variety of mirrorless cameras.
Right off the bat, take a look at the mounts that the NiSi 15mm F/4 Sunstar lens supports: Canon RF mount, Sony E mount, FUJIFILM X mount, and Nikon Z mount. You won't need to reach for an adaptor to use the lens if your camera isn't supported; it more than likely is.
The super wide angle 15mm lens isn't quite as fast as some of the glass we've looked at of late, but it's still a good kit option. Its aperture ranges from F/4 to F/22, it accepts 72mm filters and also supports NiSi's 100mm filter system, the minimum focusing distance is 7.87 inches (.2 meters), and the maximum magnification is 0.13x.
In addition, the optical design is 12 elements in 10 groups, it weighs just over a pound (about .453 kg), has minimal distortion and vignetting, and features a manual focusing operation.
So why the name Sunstar? According to NiSi, the lens will create a 'star effect' with a strong enough light, such as the sun, and the promise the effect happens at any aperture setting.
You can choose your mount and pre-order the NiSi 15mm F/4 lens now for only $579 USD, and it will ship by February 2021. I noticed the Canon RF and mount options are already on backorder, as of this writing.
Check out the video below for more details: