Photographers imaging in monochromatic light, such as Hydrogen Alpha, using an electronic sensor frequently encounter a wavy pattern of light and dark lines superimposed over their images. These lines are called interference fringes, interference patterns, banding, or Newton's Rings. In long focal ratio and/or narrowband monochromatic applications, the nearly parallel light can internally reflect inside the image sensor or camera, causing an addition or subtraction of the light waves, resulting in the observed pattern.
You can solve this problem by tilting the camera off axis. The tilt changes the angle of incidence and optical path lengths inside the image sensor, mitigating the interference.
Slightly loosen the thumbscrews and slide the two halves of the Interference Eliminator apart, such that the camera tilts. Take a few images with the camera to check for the interference pattern. (Use high contrast settings in preview mode). Slide further apart if the pattern is still evident. Tilt it the minimum amount to eliminate fringes - too far and focus could be lost at the top and bottom of the image, especially in fast focal ratio systems. If maximum tilt is reached without satisfactory effect, try full tilt in the opposite direction. In some severe instances the interference pattern may not be completely removable, but it will be reduced to where other techniques such as flatfielding or compositing can make the image acceptable.
Interface:T2 each side
Height: 11mm without the T2-T2 adapter