Selectively blocks light pollution from mercury and sodium vapor lights Achieves over 97% light transmission for maximum brightness 60nm bandpass enhances nebula contrast while maintaining natural star fields Optimized for 2" focusers and accessories Ionbeam-hardened coatings for scratch resistance and durability Description FAQ Specifications In the Box Downloads Warranty Celestron UHC/LPR Filter - 2" The Celestron UHC/LPR Filter for 2" eyepieces dramatically increases contrast by selectively blocking artificial light pollution and natural sky glow, achieving over 97% transmission of critical nebula wavelengths within its 60nm passband. Optimized for telescopes from 4" to 11" in aperture, it darkens the sky background and includes a specific passband for the 656nm H-Alpha line, making faint emission structures visible from the city or deep-sky sites. Blocking Key Light Pollution Lines in 4" to 11" Telescopes This Ultra High Contrast (UHC) filter is engineered to reject the specific wavelengths produced by mercury vapor, high and low-pressure sodium vapor lights, and the neutral oxygen emission that causes natural sky glow. By eliminating this unwanted light, the background sky appears significantly darker, allowing the faint light from emission nebulae to stand out. This targeted rejection is effective in telescopes from 4" to 11" in aperture, where maximizing every photon is critical. A 60nm Passband Delivering >97% Peak Transmission The filter's design centers on a moderately wide 60nm passband, which allows it to boost nebula contrast without sacrificing a natural-looking star field. Within this window, advanced multi-layer dielectric coatings achieve a peak transmission of over 97%. This high efficiency ensures that views remain bright and detailed, preventing the dimming effect that can occur with less advanced filters and making it an ideal choice for smaller telescopes. Hardened Coatings and a 656nm H-Alpha Passband for Imagers Celestron utilizes plasma-assisted and Ionbeam-hardened coatings, creating a durable, scratch-resistant surface that withstands regular use and cleaning. For astrophotographers, the filter's design is especially valuable as it includes an efficient passband for the critical H-Alpha emission line at 656nm. This allows DSLR and color camera users to capture the deep reds of hydrogen-rich nebulae that are often lost in city light. UHC/LPR vs. Standard Broadband Filters: A Clear Contrast Advantage Compared to a typical broadband Light Pollution Reduction (LPR) filter, the Celestron UHC/LPR provides a noticeable improvement in contrast on emission and planetary nebulae. While a broadband filter offers a more general reduction of light pollution, the UHC design more aggressively targets specific nuisance wavelengths. Sky Background: The sky view through the UHC/LPR is significantly darker, making it easier to detect the faint, extended structures of objects like the Veil Nebula (NGC 6960). Nebula Detail: Emission nebulae appear more defined and "pop" from the background, revealing subtle shadings and structures that are washed out with a less selective filter. Natural View: The 60nm passband is wide enough to maintain relatively natural star colors, avoiding the heavy color cast associated with extremely narrow "line" filters. What is the difference between this Celestron UHC/LPR and a standard broadband filter? The Celestron UHC/LPR (Ultra High Contrast/Light Pollution Reduction) filter has a narrower passband (around 60nm) that more aggressively isolates the key wavelengths from emission nebulae while strongly rejecting light pollution. A standard broadband filter has a wider passband, resulting in a brighter but lower-contrast image. The UHC design produces a darker sky background and makes nebulae stand out more distinctly. Is the Celestron UHC/LPR filter only for viewing nebulae? While its primary purpose is to enhance emission, planetary, and reflection nebulae, it is not strictly limited to them. The filter can help darken the sky background and improve contrast on any deep-sky object, though the effect will be most dramatic on nebulae. It is not recommended for viewing galaxies or star clusters, as it will dim these objects without providing a significant contrast benefit. Will this filter help me see the Orion Nebula (M42) from my suburban backyard with an 8" SCT? Absolutely. An 8" SCT is an excellent instrument for this filter. The Celestron UHC/LPR will significantly darken the washed-out suburban sky, dramatically improving the contrast of the Orion Nebula (M42). You will be able to see more of the faint, extended nebulosity and potentially resolve more detail within the Trapezium region. I have a 6" Newtonian at a dark sky site. Is the Celestron UHC/LPR filter still useful? Yes, even at a dark sky site, this filter is very effective. It works by blocking natural sky glow in addition to artificial light pollution. By using the filter on objects like the Lagoon Nebula (M8) or the Swan Nebula (M17), you will see a noticeable increase in contrast, making the nebulosity appear more detailed and defined against the blackness of space. Is the Celestron 2" UHC/LPR filter suitable for astrophotography? Yes, it is well-suited for imaging with color cameras like DSLRs or dedicated astronomy cameras. The filter's broader 60nm bandpass retains good star color, and its efficient transmission of the H-Alpha wavelength at 656nm is crucial for capturing the red emission regions in many popular deep-sky targets. How do I attach and use the 2" UHC/LPR filter? The Celestron 2" UHC/LPR filter has standard 2" filter threads (M48x0.75). It can be threaded directly onto the barrel of any 2" eyepiece or onto a 2" nosepiece for a camera. Simply screw it on until it is finger-tight and insert the eyepiece or camera into your telescope's focuser as usual. Filter Size 2" Filter Type UHC/LPR (Ultra High Contrast / Light Pollution Reduction) Peak Transmission >97% Passband 60nm H-Alpha Passband 656nm Coatings Multi-layer dielectric, Ionbeam hardened Recommended Telescopes 4" - 11" aperture UHC/LPR Filter - 2" × 1 Protective Plastic Case × 1 Download Celestron Software This product is covered by Celestron's 2-Year Limited Warranty. For more details, please visit the Celestron Warranty Policy page.
