Astronomik 2″ IR Block Filter

Astronomik IR Block 2″ filter

If you have ever noticed halos around bright stars, poor contrast, or a mysterious haze in your images, infrared light is very likely the cause. Your camera captures infrared radiation even when you do not want it to. The Astronomik IR Block 2″ filter solves this problem in an elegant and effective way - it blocks the infrared part of the spectrum while leaving the visible range completely untouched, with transmission above 99%.

More than just an IR filter

The Astronomik IR Block is not an ordinary infrared filter. If you compare its transmission curves with products from other manufacturers, you will notice something interesting. What Astronomik calls "IR Block" would be labeled "UV-IR Block" by most competitors - meaning it blocks both ends of the spectrum, ultraviolet and infrared. And what Astronomik calls its own UV-IR Block outperforms comparable products from other brands on the global market. In short: you get more than the name suggests.

Wide compatibility and practical design

The filter is optimized for a wide range of focal ratios, from f/0.5 to f/50. This means it works reliably with fast newtonians and aplanats as well as slow refractors or SCT telescopes. Typical transmission in the visible range exceeds 99%, so you lose almost nothing in exposure time.

The 1 mm glass thickness makes this filter parfocal with other filters in the Astronomik range. When you switch filters, you do not need to refocus - a small but very useful advantage during a long imaging session.

Who is this filter for?

The IR Block filter is designed primarily for digital astrophotography with cameras that have low sensitivity in the ultraviolet range. This includes:

• Webcams
• Meade DSI and LPI cameras
• Most video astronomy systems
• CCD cameras used with optics that contain refractive elements - lenses, field correctors, Barlow lenses
• DSLR cameras with a so-called MC modification

For unmodified DSLR cameras or optical systems without any refractive elements - such as a pure Newtonian reflector without a corrector - the imaging benefit of this filter is lower. However, even in those setups it remains useful as a physical dust protection for your optics.

Not sure which filter is right for you?

Here is a quick guide to help you choose:

• If your camera is sensitive to short ultraviolet wavelengths, consider the Astronomik UV-IR Block filter from the same range instead.
• If you are working with a system that has no refractive elements at all - for example, a pure Newtonian telescope without a corrector - take a look at the Astronomik MC Clear filter.
• If you are imaging under heavily light-polluted skies, the Astronomik CLS CCD filter may be a better choice. It handles not only infrared light but also the unwanted emissions from sodium and mercury street lamps.

Build quality and durability

The Astronomik IR Block 2″ filter is a precision-made accessory built to last. The glass is resistant to humidity and mechanical damage. Combined with its parfocal design and exceptional transmission, it makes a reliable companion for years of observing and imaging.

Key specifications at a glance