ZWOptical IR-Pass filter 1.25″
If you are interested in planetary astrophotography or daytime and twilight observation, an infrared filter is a tool that significantly expands your possibilities. The ZWOptical IR-Pass filter in the standard 1.25″ diameter transmits the infrared part of the spectrum while blocking visible light, opening up an entirely new perspective on objects in the solar system. Its multi-layer anti-reflection coating ensures high transmission in the IR band and minimizes unwanted reflections within the optical system.
What is the IR-Pass filter designed for?
The IR-Pass filter is not intended for visual observation - the human eye perceives virtually no image in infrared light. The true domain of this filter is planetary and lunar astrophotography with CCD or CMOS cameras that are sensitive to IR radiation. In the infrared band, the influence of atmospheric scattering is significantly reduced and seeing appears more stable, so images of planets - Mars, Jupiter, Saturn, Uranus, and Venus - are typically sharper and with better contrast than when photographing in the full visible spectrum. The filter is also well suited for observing and photographing the Moon and comets, even in daylight or at twilight, where it suppresses the bright blue components of the sky and improves contrast.
Reducing light pollution
An important practical advantage of the IR-Pass filter is the suppression of light pollution. Although IR-Pass filters are not primarily intended as narrowband filters for nebulae, the influence of the orange glow from sodium lamps and modern LED lighting is significantly reduced in the infrared band. This is particularly appreciated when photographing from urban or suburban locations.
Construction and compatibility
The ZWOptical IR-Pass filter 1.25″ is mounted in a precisely machined aluminium threaded cell in the standard 1.25″ format, which screws directly into the focuser or into a filter holder compatible with the same standard. The multi-layer coating of the optical element ensures a long service life even with regular astrophotographic use. The filter is fully compatible with ZWO planetary cameras, but naturally works with any camera or focuser with a 1.25″ thread.
Who is this filter for?
The ZWOptical IR-Pass filter is primarily appreciated by planetary photographers who want to take advantage of infrared radiation for detailed images of planetary surfaces and the Moon, even in poor seeing conditions or from light-polluted locations. It is suitable both for experienced astrophotographers building a set of planetary filters and for enthusiasts who are just beginning to experiment with the infrared spectrum and are looking for a reliable and affordable filter from an established brand.
Key features at a glance
- Transmits infrared light, blocks visible light
- Multi-layer anti-reflection coating for high IR transmission
- Reduces the effect of atmospheric seeing during planetary imaging
- Improves contrast when observing the Moon, planets, and comets
- Helps suppress light pollution from sodium and LED sources
- Standard 1.25″ aluminium threaded cell
- Compatible with ZWO cameras and all standard 1.25″ focusers
- Suitable for both beginner and experienced astrophotographers
Specifications
| Parameter |
Value |
| Filter type |
IR-Pass (infrared pass filter) |
| Filter diameter |
1.25″ |
| Cell material |
Aluminium |
| Coating |
Multi-layer anti-reflection |
| Intended use |
Astrophotography (CCD/CMOS cameras), daytime and twilight observation |
| Compatibility |
All 1.25″ focusers and filter holders, ZWO planetary cameras |
