Astronomik CLS-CCD filter - manufacturer feedback
FYI.
I asked Astronomik about exposure time using the CLS-CCD filter. I know that exposure time depends on many factors.
What I wanted to know, was how to use the filter optimally. Noise in the background is particularly obvious even with exposures of less than 90 seconds because the light pollution/skyglow that usually fills the background is filtered out leaving sensor noise, which is substantial on the Canon 1000D.
The main points provided by Astronomik are;
Obviously "...more than 80% of images are unaffected by tracking errors."
"The background is not brighter than 15% of the dynamic of the sensor."
anyone know how to apply this?
"Depending on the brightness of your sky, stop the exposure when the background of your images is easily visible, but still dark."
Taking a series of short exposures, as you might without a filter, doesn't necessarily work, and one is only stacking noise (that's my experience). Images only become useful once the background is filled in and sensor noise is no longer visible... pretty straight forward
Next question - is there an upper limit, or is this just a function of overdoing areas of brightness?
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