Astronomik UHC 2" — ultra-high-contrast nebula filter The Astronomik UHC (Ultra High Contrast) filter is Astronomik's first choice for visual observation of emission nebulae. It passes the OIII, H-beta and H-alpha lines with high transmission while blocking sodium and mercury-vapour lamp lines and natural airglow, which sharply increases nebula contrast…
Manufacturer model: Astronomik UHC 2" (M48), 10210200 · Specifications checked against manufacturer data on 2026-11-03
The Astronomik UHC (Ultra High Contrast) filter is Astronomik's first choice for visual observation of emission nebulae. It passes the OIII, H-beta and H-alpha lines with high transmission while blocking sodium and mercury-vapour lamp lines and natural airglow, which sharply increases nebula contrast against the sky.
Astronomik rates the UHC as very good under dark skies with telescopes of any focal ratio, and very good under urban skies with telescopes from 4 inches (100 mm) aperture. It covers focal ratios from f/3 to f/15. Astronomik also recommends it for observing Jupiter's cloud bands and for separating double stars, and it can be used for imaging from heavily light-polluted sites.
| Filter type | UHC nebula filter |
|---|---|
| Transmission range | 480–505 nm and above 645 nm |
| Bandwidth (FWHM) | 25 nm |
| H-beta (486 nm) | Typically 95% |
| OIII (496 / 501 nm) | Typically 95% |
| H-alpha (656 nm) | Typically 95% |
| Focal ratio range | f/3 to f/15 |
| Manufacturer code | 10210200 |
|---|---|
| Format | 2-inch cell, M48 × 0.75 thread |
| Glass thickness | 1 mm |
| Parfocal | With other Astronomik filters |
| Made in | Germany |
Astronomik UHC 2" product page
UHC (25 nm, 10210200), not UHC-E (45 nm). Under urban skies best from 4 in (100 mm) aperture.
| Transmission range (nm) | 480–505 and above 645 |
|---|---|
| Typical transmission hbeta (%) | 95 |
| Typical transmission oiii (%) | 95 |
| Typical transmission halpha (%) | 95 |
Data sheet
Specific References
Astronomik UHC 2" — ultra-high-contrast nebula filter The Astronomik UHC (Ultra High Contrast) filter is Astronomik's first choice for visual observation of emission nebulae. It passes the OIII, H-beta and H-alpha lines with high transmission while blocking sodium and mercury-vapour lamp lines and natural airglow, which sharply increases nebula contrast…
Manufacturer model: Astronomik UHC 2" (M48), 10210200 · Specifications checked against manufacturer data on 2026-11-03
