Unlike other companies, we don’t force our customers to purchase two expensive variable ND filters.  The reason why they sell their variable NDs divided between 2-5 stops and then 6-9 is so that they can charge you more and eliminate that faint X that results from the diffraction grating. But having to swap out ND filters is annoying during an outdoor shoot.  Lighting conditions constantly change.  Having to clean and swap filters in between takes up precious time. STC’s approach is to make the photographer’s life as simple as possible. Our approach is to give you a 1-10 stop filter in one VND, saving you time and money!  Experienced photographers know that changing the focal length, angle to the subject and the sun is an effective and faster solution.