DeltaOptical IR-Cut 2″ filter
If you photograph the night sky with a CCD camera and want to get the maximum sharpness from every shot, the DeltaOptical IR-Cut infrared blocking filter is exactly what your optical system needs. This filter effectively cuts off the unwanted infrared part of the spectrum and allows you to use the full potential of your telescope - without the compromise of blurred stars caused by uncorrected chromatic aberration in the IR range.
Why use an IR-cut filter with your telescope?
Most refractors and telescopes with lens elements are designed and chromatically corrected primarily for the visible spectrum. Only top-tier instruments - such as Takahashi models - include correction extending into the infrared region. In standard and mid-range telescopes, infrared radiation therefore reaches the sensor at a different focal point than visible light, which shows up in photographs as a loss of sharpness and bloated star discs.
The DeltaOptical IR-Cut filter blocks radiation with a wavelength of λ > 690 nm, eliminating this unwanted component. The result is noticeably sharper and more pinpoint stars in your images.
Full H-alpha transmission for emission nebula imaging
The IR-Cut filter for astrophotography of emission nebulae is designed so that the astronomically valuable hydrogen H-alpha line (λ = 656 nm) is not suppressed. This emission is one of the most important components of radiation from emission nebulae. By preserving it, the filter ensures that your images will contain all the detail of these objects. H-alpha transmission through this filter is complete - without any restriction.
Optical and mechanical specifications
| Parameter |
Value |
| Filter size |
2″ |
| Blocking wavelength |
λ > 690 nm (infrared blocked) |
| H-alpha transmission (656 nm) |
Full - 100% |
| Visible range transmission |
up to 95% |
| UV range |
Not blocked |
| Frame material |
Anodized aluminum |
| Mounting |
Standard 2″ threaded cell |
Excellent light transmission in the visible range
In the visible band, the filter achieves a maximum transmission of 95%, meaning minimal light loss and an excellent signal-to-noise ratio during long exposures. UV radiation is not blocked by the filter, so no additional restriction occurs in the ultraviolet range.
Precision construction from anodized aluminum
The filter body is precision-manufactured from anodized aluminum, which guarantees a long service life, resistance to mechanical damage, and thread stability during repeated attachment and removal. The build quality meets the standards that astronomers expect from quality accessories - solid, lightweight, and reliable.
Who is this filter designed for?
The DeltaOptical IR-Cut 2″ infrared blocking filter is particularly appreciated by photographers using monochrome or color CCD and CMOS cameras that are sensitive in the IR range, working with apochromatic or semi-APO refractors without full IR correction. It is an ideal companion for:
- Broadband astrophotography with CCD and CMOS sensors
- Imaging emission nebulae where preserving the H-alpha line is essential
- Use as a base component in a filter system combined with other narrowband filters
- Any refractor or lens-based telescope without built-in IR correction
About Delta Optical
Delta Optical is a brand with a long tradition in premium optics, trusted by astronomers and naturalists around the world. Products are developed with emphasis on manufacturing precision, optical quality, and the practical needs of users - from beginners to experienced observers and astrophotographers. The IR-Cut filter is a convincing example of this: a well-thought-out specification, quality materials, and precise workmanship that delivers a genuinely measurable improvement in sensor results.
