Arrow Direction

People who purchase an unmounted filter will quickly note there is an arrow drawn on the edge of the filter.

Due to the nature of the coating there is a minor performance gain to be had by orientating the arrow correctly. The arrow should be point TOWARDS camera. Imagine the arrow is the direction of the light.

For people who purchase the mounted filter, it is assumed that telescopes usually present a male thread. The female threads mount the male thread and thus present their male thread for camera threads to follow suit.

If your system differs from a standard configuration it is best to do nothing, the performance gain is small enough that risking scratches and damage to reverse the filter are not worth the risk. Adjustable spanners (top left of image) are the correct too for the job but its easy to scratch and damage the filter. We have plastic spanners in development so feel free to enquire for a free prototype when ordering.