Astronomik 1.25″ UHC-E Filter
Enhanced Urban Observation Filter for Small Telescopes
The **Astronomik UHC-E filter** represents the perfect balance between contrast enhancement and light transmission, specifically designed for observers using smaller telescopes in urban environments. With its FWHM of 45nm, this filter effectively blocks unwanted artificial lighting from street lamps, sodium vapor lights, and mercury vapor sources while maintaining excellent star visibility.
Key Features and Benefits
Superior Light Transmission
- Transmits up to 94% of desired light
- Passes wavelengths from 480nm to 525nm and above 645nm
- Enhanced star visibility compared to standard UHC filters
- Ideal for telescopes with apertures up to 5″ (127mm)
Advanced Optical Design
- 1mm glass thickness for minimal optical distortion
- Parfocal with other Astronomik filters
- Diffraction-limited performance maintains telescope's optical quality
- Multi-layer interference coating technology
Versatile Applications
Visual Observation
The UHC-E filter excels in **urban astronomy conditions**, providing excellent performance for telescopes with apertures up to 125mm. While standard UHC filters may be preferable under dark skies, the UHC-E shines in light-polluted environments where maximum light gathering is crucial.
Astrophotography Excellence
- DSLR compatibility: Near-perfect color balance with original and modified cameras
- Film photography: Excellent results with extended exposures
- CCD imaging: Outstanding performance when combined with IR-blocking filters
- Webcam deep-sky imaging: Exceptional results in high light pollution areas
Specialized Observations
- Jupiter's atmospheric features and cloud bands
- Enhanced double star separation
- Comet observation (carbon spectral line transmission)
- Emission nebulae under urban skies
Technical Specifications
Optical Performance
- FWHM: 45nm
- Light transmission: Up to 94%
- Bandpass: 480-525nm and >645nm
- Filter thickness: 1mm precision optical glass
Construction Quality
- High humidity resistance
- Scratch-resistant surface
- Age-resistant coatings
- Professional aluminum cell construction
- Supplied in premium protective case
Filter Selection Guide
For telescopes larger than 5″ (127mm), consider the standard Astronomik UHC filter for maximum contrast enhancement. Observers with 8″ (200mm) telescopes may benefit from the specialized Astronomik OIII filter for specific nebulae types. The UHC-E represents the optimal choice for smaller instruments where light gathering capability is paramount.
Professional Recommendations
Optimal Use Conditions
- Urban and suburban observing sites
- Telescopes up to 5″ aperture
- DSLR astrophotography in light-polluted areas
- Medium exit pupil distances
Performance Ratings
- Visual observation (dark sky): Good - UHC preferred
- Visual observation (urban): Excellent for small telescopes
- DSLR photography: Excellent color balance
- CCD imaging: Excellent with IR blocking
- Deep-sky webcam: Outstanding in light pollution
The Astronomik UHC-E filter transforms urban astronomy by effectively managing light pollution while preserving the natural beauty of celestial objects. Its carefully engineered spectral response ensures that both visual observers and astrophotographers can achieve remarkable results even from city locations.
