The ProPlanet IR 807 is intended as a supplement to the ProPlanet IR 742, for very poor seeing conditions and telescopes with sufficient light gathering power.
Mode of operation: The ProPlanet IR 807 filter cuts off the visible part of the spectrum and only opens at a wavelength of 807 nm. This blocks the areas of light that are particularly sensitive to seeing and allows the areas of longer wavelength light that are significantly less sensitive to seeing to pass through. This approach visibly reduces seeing problems in planetary and lunar photography without significantly reducing the sensitivity of the imaging sensor.
The loss of sensitivity in most cameras with the IR 807 compared to the IR 742 is about one f-stop, corresponding to 50%, or, conversely, a doubling of the exposure time. The one-millimetre-thick filter is homofocal with all other Astronomik filters.
The filter is not sensitive to moisture, does not age and is scratch-resistant. It comes in durable packaging.
