About the Lumicon Infrared Blocking Filter - 2"...
The Lumicon Infrared Blocking Filter is used primarily to "bracket" the color-corrected band of refracting telescopes. The Minus Violet and Infrared Blocking Filters can also be used as "visible" filters in RGBV (red-green-blue-visible) astrophotography with reflecting telescopes. The larger Minus Violet filters are for telephoto lenses.
Most digital/CCD cameras have built-in infrared filters, in which case the Lumicon Infrared Blocking Filter may be used. The choice would depend on how far into the blue your primary lens is color-corrected. The Minus Violet filter blocks wavelengths shorter than about 420nm; the Infrared filter blocks wavelengths shorter than about 400nm. If your camera does not have a built-in infrared filter, the Infrared Blocking Filter is recommended, which blocks all wavelengths longer than 750nm.
Lumicon Infrared Blocking Filter - 2" Features...
- Infrared filter blocks wavelengths shorter than about 400nm
- Can also be used as "visible" filters in RGBV (red-green-blue-visible) astrophotography with reflecting telescopes
- Made using thin-film dielectric coatings on optically flat glass
- These exclusively designed dielectric coatings consist of over 30 alternating layers of several different materials
- Each layer is about a wavelength of light thick and has a thickness accurate to 2 - 3 angstroms
Lumicon Infrared Blocking Filter - 2" Specifications...
Filter Type: Infrared Blocking
Application: Photographic
Filter Size: 2"
Presentation: Round, threaded cell
Lumicon Product Number: LF3145