With the "Starburst 6-Point Filter," I expected the typical, high-quality standard associated with "K&F CONCEPT" accessories—and I was not disappointed.
The specific model I have is the 82mm variant.
The frame is constructed from high-quality aluminum and consists of two parts—or, strictly speaking, three parts in total.
It is composed of a base frame with an overall outer diameter of 85mm. The exterior of this base frame features high-quality, uniform, and very grippable knurling. Situated just before the knurling is the mounting thread; in this case, it has an 82mm diameter and a depth of 2.5mm, allowing it to be screwed into lenses or other accessories, such as adapter rings.
The front section serves as the housing for the filter glass. It also features an 85mm outer diameter and is equipped with an 82mm front thread for attaching additional filters. The filter glass is not glued in place; instead, it is secured by screwing it down with the third aluminum component—a narrow retaining ring. This design preserves a thread depth of 2mm on the front for mounting further accessories. The outer surface of the front ring is smooth, but it features two opposing knurled grip sections that actually protrude slightly beyond the ring's outer diameter.
This design allows the front section of the filter to be rotated intuitively and with great precision.
Consequently, the orientation of the six light rays can be adjusted exactly as desired.
The filter components rotate against one another very smoothly and uniformly, offering just the right amount of resistance. This ensures precise adjustment without the filter inadvertently shifting out of position on its own.
All threads are first-class and fit perfectly. The filter screws accurately into both my lenses and my step-down rings. Other 82mm filters attach to the front of this filter without any issues.
The matte-black finish has proven to be highly scratch-resistant so far and lends the filter a professionally sleek and premium appearance. The aluminum frame is a mere 7.5 mm thick overall and weighs just 22 g. Excluding the 2.5 mm screw threads, the filter adds only 5 mm to the lens profile once mounted, making it suitable even for wide-angle lenses.
The optical glass also feels and performs to a very high standard.
We have full confidence in the 18-layer coating applied here. In any case, the surface exhibits very low reflectivity. It is resistant to fingerprints and minor smudges, and is very easy to clean.
Water droplets do not adhere to the glass; instead, they simply bead up and roll off.

The filter transforms bright point light sources within the image into a six-pointed star! While the appearance of this effect depends on various factors, it generally looks very pleasing and harmonious.
Thanks to the fully rotatable filter frame, the orientation of the six-pointed star can be precisely adjusted.
When used sparingly and with intent, this proves to be a highly effective and high-quality filter.
As an explicit "effect filter," it naturally alters the optical performance of a lens; however, no undesirable side effects or impairments are noticeable.
A highly recommended filter for specific creative applications. With the 82 mm version and the use of step-down rings, it is compatible with a wide range of lenses.

Using this filter and shooting with it is genuinely enjoyable—and it has truly earned its 5-star rating.