This is a light box used for taking "flats". It provides an even, white illumination through the use of ultra-bright LES lights inside and sign-makers plastic to diffuse the light. It is made of simple foam board. With the telescope pointed at the light box, I take a series of exposures (5 seconds or so). These exposures are then used during image calibration to flatten out uneven field illumination (vignetting) and to cancel out dust motes that may be in the optical train.
© Barry Etter, Mocksville, NC