ZWO IR-blocking filter D25

ZWO IR-blocking filter D25 is an interference filter that effectively blocks infrared light and protects your ASI camera from dust and moisture. For refractor telescopes, this filter prevents the focus position of visible light and IR light from shifting, resulting in razor-sharp images. For mirror telescopes, a clear glass filter suffices as a dust cap, but with this IR blocker you are always assured of optimal sharpness and contrast.

Key benefits
✓ 90 % transmission in visible light for maximum brightness without color transition
✓ Blocks IR light and prevents blur caused by focus differences
✓ Protects sensor from dust, moisture and scratches during long sessions
✓ Direct fit to M42 thread (D25 size)
✓ Multi-layer anti-reflection coating minimizes loss and halos around stars

Practical application
Screw the IR-blocking filter D25 as the first element into your filter wheel or directly onto your camera mount. On refractors, it increases sharpness and reduces focus problems. Combine with narrowband or color filters for added contrast and color fidelity.

Technical specifications

• Size: D25 (M42 × 0.75)
• Type: IR-blocking interference filter
• Transmission: 90 % in visible spectrum
• Coating: multi-layer anti-reflection
• Glass thickness: 2 mm
• Application: broadband and narrowband astrophotography (photographic)