Astrodon - 50mm Unmounted UVenus Filter

Astrodon introduces a breakthrough in UV filters for CCD imaging. A  durable, hard--coated UV filter of the highest quality having the best transmission available.

• Image the cloud structure of Venus and  Jupiter with CCD cameras on a telescope
• Use for general UV photography  (flowers, insects, forensics)

The Astrodon-Schuler UV filter has traditionally been used for imaging Venus. It is made from several colored glasses, but only transmits ~ 65% of incoming UV light in the 300 - 400 nm region.

Another vendor recently discontinued a 1.25" mounted UV filter due to NIR light leakage, but offers a 2" unmounted version that only reaches 80%T. Astrodon offers you both sizes and higher performance.

Like Astrodon's highest quality Generation2 LRGB filters, the UVenus filter minimizes halos around bright stars.

Astrodon UVenus filters are guaranteed to achieve >90% transmission. The actual scan below has an average transmittance of 98.2% from 325 - 381 nm, while minimizing out-of-band light leakage. This outstanding performance saves you time when imaging weak UV signals, while providing high contrast due to low light-leakage.

You do not need a separate filter to block the NIR with the UVenus filter.

Specifications:

• 1.25" mounted and 49.7 mm diameter unmounted
• 3.000+/-0.025 mm substrate thickness
• Single, striae-free fused silica substrate
• 1/4 wave substrate prior to coating
• < 0.5 arcminute parallelism before coating
• Hard coated to edge
• Guaranteed to > 90%T peak transmission (>94% typical)
• <0.01%T 285-305 nm; <0.1%T 420 - 1100 nm
• Image Venus during daylight due to elimination of all visible light
• Proudly made in the U.S.A.
  
  

Warning:

This filter is NOT to be used for visual observations, specifically the sun or UV light sources.