Optolong UHC Filter 2 inch

Optolong UHC Filter 2 inch: more contrast on emission nebulae

UHC stands for Ultra High Contrast: this filter primarily allows the emission lines of nebulae (including H-beta, OIII, and H-alpha) to pass through while blocking light pollution from streetlights and skyglow. Emission nebulae like the Orion Nebula or the Ring Nebula visibly gain contrast from this, even when viewed through the eyepiece.

Under a light-polluted sky, a UHC filter is often the difference between a faint suspicion of a nebula and truly seeing it.

Visual and photographic

Visually, the filter provides a dark background against which nebulae stand out. Photographically, it extends the usable exposure time under city lights. The 2-inch size fits larger eyepieces and prevents vignetting on large sensors.

When UHC is the right choice

Choose UHC for emission nebulae and planetary nebulae. For galaxies and star clusters, a broadband filter like the L-Pro lets more of the continuous spectrum through.

Featured accessories

A 2-inch zenith mirror or filter holder makes changing filters comfortable.

For whom yes and for whom no

• ✓ Visual observers of emission nebulae under light-polluted skies
• ✓ Photographers looking for an affordable contrast filter
• Anyone observing mostly galaxies: they gain little from a UHC filter

Specifications

You can find more accessories for this merk at the Optolong merk page.