Περιγραφή
The Astronomik ProPlanet 807 IR-pass Filter is ideal for imaging the Moon and planets, notably Mars with telescopes from 10″ (250mm) aperture.
This filter is an ideal complement to the ProPlanet IR 742 for use with converted DSLR cameras, CCD cameras and Webcams. The effects of seeing are distinctly reduced. It is your entry into previously unknown dimensions of photography of the Moon and the planets.
The ProPlanet IR 807 only allows infrared light with wavelengths of more than 807 nm to pass. In this wavelength range the effects of seeing are significantly lower than in the visible spectrum of the human eye. This allows much sharper images than are usually obtained from your device and location. Another advantage is that the sky background of advanced dawn is dark and even allows photography of planets and Moon at daylight.
Main use
The Astronomik ProPlanet IR 807 cuts off the visible part of the spectrum and allows the light of wavelengths longer then 807nm to pass. Due to this behaviour the part of the spectrum that is most sensitive to bad seeing is rejected. This approach does a big improvement to the imaging of planets and the Moon. The image is more steady than the image in the visible light.
Other uses
- The Astronomik ProPlanet IR 807 is designed to be an addition to the Astronomik ProPlanet IR 742, if the seeing is extremely bad and a larger telescope is used.
- For most cameras the exposure times doubles, compared to the Astronomik ProPlanet IR 742 or imaging in visible light, if the Astronomik ProPlanet IR 807 is used.
- Darkens the background during twilight.
- Imaging of bright planets, stars and comets by day.
- Imaging of young stars in dust clouds and stellar nurseries.
Alternatives
If the seeing is not so bad or if the telescope is smaller than 10″ (250mm) we recommend the use of the Astronomik ProPlanet IR 742.
Transmission Chart
- The horizontal axis is the Wavelength in Nanometers (nm). 400nm is deep blue, at 520nm the human eye senses green and at 600nm red. At 656nm is the famous “H-Alpha” emission line of hydrogen.
- The transmission in % is plotted on the vertical axis.
- The blue line shows the transmission of the filter.
- The most important emission lines from nebulas are shown in orange. The most important lines are from ionised Hydrogen (H-alpha and H-beta) and double ionised oxygen (OIII).
The major emission lines of artificial light pollution:
| Hg 435,8nm | Hg 546,1nm | Hg 577,0nm | Hg 578,1nm |
| Na 589,0nm | Na 589,6nm | Na 615,4nm | Na 616,1nm |
The major emission lines of nebulas:
H-β 486,1nm | OIII 495,9nm | OIII 500,7nm | H-α 656,3nm
Suitability
- Visual observation (dark skies): Unsuitable, the eye is insensitive at this spectrum
- Visual observation (urban skies): Unsuitable, the eye is insensitive at this spectrum
- Film photography: Unsuitable
- CCD photography: Reasonable, for special IR photography (as chlorophyll)
- DSLR photography (original): Unsuitable
- DSLR photography (astro modified): Unsuitable
- DSLR photography (MC modified): Good, for IR daylight photography, longer exposure time
- Webcam / Video (Planets): Very good, rejects problems with seeing, particularly with telescopes larger 250 mm aperture
- Webcam / Video (Deep Sky): Very good, rejects problems with seeing, particularly with telescopes larger 250 mm aperture
Technical Data
- More then 97% transmission for wavelengths of 807nm to 1100nm
- Blocking of wavelengths between 350nm and 790nm
- Parfocal with all Astronomik filters
- Thickness of 1mm
- Not sensitive to moisture, scratch resistant or ageing
- Optically polished substrate, striae-free and free of residual stresses
- Astronomik filters are delivered in a high-quality, long lasting, filter box
