Περιγραφή
The Astronomik ProPlanet 642 BP offers a wide range of applications for daylight IR-Photography, high-resolution lunar and planetary imaging and for taking beautiful and deep images of H-alpha regions when used for Astrophotography.
“BP” are short for “Bandpass”: The filter gives you a 200nm spectral window from 642nm to 842nm. Contrary to the other two ProPlanet filters it blocks the longer infrared. Together with the Astronomik ProPlanet 742 and the ProPlanet 807 you can now have three choices to match your needs when imaging in the IR. The Astronomik ProPlanet 642 BP will be the right choice for the best image quite often!
Three Filters in One!
Depending on your camera, the Astronomik ProPlanet 642 BP is a great tool either for daylight IR-imaging with your digital camera, or it will reduce seeing effects and enhance contrast when used for lunar- and planetary imaging, and third it will be a very good and low-priced H-alpha Filter for getting started in Deep-Sky Astrophotography of H-alpha regions.
Daylight IR-imaging
- Short exposure times, about the same as normal VIS-imaging
- Perfect choice for Infrared-Videos
High-resolution Lunar and planetary imaging
- Short exposure times
- Effective reduction of Seeing
- Enhanced contrast
- No ghosts and best sharpness due to blocking the longer IR
Deep-Sky Astrophotography of HII regions
- Best transmission of the H-alpha line at 656nm
- About 40nm FWHM with astro-modified DSLRs
- Amazing contrast under light polluted skies or moonlight
- Low priced filter for getting started in H-alpha imaging
- Easy focussing using camera display plus LiveView!
Guiding for Astrophotography
- installing the 642BP in front of your guiding camera dramatically improves guiding quality, as image-motion from one frame to the next is minimised.
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
Technical Data
- More then 96% transmission for wavelengths of 642nm to 840nm
- Blocking of wavelengths between 350nm and 630nm
- 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
