Main use of an IR-Block filter
The IR Blocker is a perfect parfocal filter. It blocks all IR light without modifying the visual part of the spectrum. It is also great as a dust protection for your telescope and camera.
- Dust protection for Schmidt-Cassegrain, Newtonian or Maksutov systems. The clip-filters can protect your DSLR cameras too.
- An alternative to that UV-IR-Blocker if your camera has a low sensitivity at short wavelengths.
- An alternative to the MC Clear filters if your system has any refracting elements
You should think about using the UV-IR blocker if your camera has a high sensitivity at short wavelengths. Think about using the MC Clear glass if you have a system without any refracting elements. If you do color imaging from light polluted areas, think about using the CLS CCD filter for luminance data instead!