BP is an abbreviation for Bandpass: the filter opens at 642nm and closes again at 842nm . In contrast to the other two ProPlanet filters from Astronomik, it blocks the long-wave infrared.
Together with the ProPlanet 742 and ProPlanet 807 astronomical filters, you can now select three wavelength ranges for recordings in the infrared in order to obtain optimal images.
With the ProPlanet 642 BP you get three filters in a single product: Depending on which camera you use the filter with, it is a great tool for infrared photography with a digital camera, reduces and enhances seeing in high-resolution planetary and moon photography contrasts. It is also an inexpensive H-alpha filter for entry into deep sky astrophotography of emission nebulae.
Infrared Photography:
- High-contrast images with excellent color differentiation
- Great rendition of the Wood effect
- Avoiding hot spots
- Exposure times as under "Normal light"
- Great for IR filming!
High-resolution moon and planetary photography:
- Short exposure times
- Effective reduction of air turbulence (seeing)
- Enhanced contrasts in the red range
- No ghosting and best sharpness by blocking the long-wavelength IR
Deep-sky astrophotography of H-alpha nebulae:
- Maximum transmission of the H-alpha line at 656nm
- Enormous gain in contrast under a light-polluted sky or in moonlight
- Inexpensive entry into H-alpha photography
- Easy focusing with LiveView possible!
Another area of application: Guiding in astrophotography . The 642BP in front of your autoguider improves the quality of your tracking significantly as it minimizes the image jumps caused by seeing!
