Flat field mask 233mm

A flatfield box (FFB) creates the flats required for precise calibration of astrophotos. This eliminates vignetting (a dark edge) and prevents shadows from dust particles on the image. This is not only aesthetically important - only perfect “flat” images can be stretched enough for faint signals to become visible. It can increase the contrast, remove speckling from the background, and make the faintest object tails visible.

The FFB’s special properties:

• Very colour-neutral light: the colour channels quickly become fully saturated and this is the ideal basis for a successful flat, even with narrow band filters.
• Extremely uniform illumination: considerably better than traditional flatfield generators which produce faint variations across the surface and at the edge.
• The LEDs flicker at a different frequency to the mains, meaning that significantly shorter exposure times can be used without a “venetian blind” effect, e.g. 1/500 seconds
• Only around 10% as bright as many other models, so that they are also not too bright for highly sensitive CMOS and CCD cameras.
• The innovative round foam mask helps to create a secure fit on suitable telescope lens tubes - simply place on top, push on and the lens tube will slip inside

The flatfield boxes have a standard 12V connection (5.5mm/2.1mm jack, centre positive) and comes with a vehicle plug (cigarette lighter cable).