Baader Planetarium 1.25″ U-Venus UV filter (320-380nm)
Venus looks featureless at first glance - just a uniform white disc with no visible detail. But that is only true in visible light. Switch to the ultraviolet part of the spectrum and suddenly the planet's atmosphere reveals fascinating cloud structures, bands and swirls that are otherwise completely hidden. That is exactly what the Baader Planetarium U-Venus UV filter is designed for - a specialized tool for anyone serious about observing and imaging Venus.
Narrow UV bandpass for maximum contrast
The filter is designed to transmit a narrow band of ultraviolet radiation from 320 to 380 nm, while keeping transmission in the visible spectrum intentionally very low. This eliminates interfering visible light, allowing only the UV component reflected from the tops of Venus's cloud layers to reach the eyepiece or camera sensor. The result is high-contrast imagery showing atmospheric detail that would otherwise remain invisible.
The filter is mounted in a standard 1.25″ threaded barrel, making it compatible with the vast majority of eyepieces, camera adapters and telescopes equipped with a 1.25″ focuser.
Recommended use and setup
The U-Venus filter is primarily intended for planetary photography with CCD or CMOS cameras that have good UV sensitivity - used without an IR/UV cut filter, which is standard on most consumer cameras. For best results, we recommend pairing it with:
- A planetary camera with sufficient UV sensitivity (unmodified or UV-sensitive sensor)
- A telescope with good UV transmission - apochromatic or ED refractors generally outperform Newtonian reflectors with standard mirror coatings in this spectral range
- Good atmospheric seeing conditions
The filter can also be used visually. During live-view sessions under steady seeing, the results on screen can be genuinely impressive.
For beginners and experienced planetary imagers alike
The Baader U-Venus 1.25″ UV filter is a popular choice among experienced planetary photographers as well as observers just starting to push their imaging to the next level. Baader Planetarium is a well-established German manufacturer of astronomical optics with decades of experience, whose filters are recognized worldwide as a standard in both amateur and professional astronomy. Precise construction, accurately defined spectral transmission and reliable threaded mounting come as standard.
If you are looking for a way to extract the maximum detail from your Venus images and reveal structures that simply cannot be seen with ordinary filters, this is the right tool for the job - a specialized yet affordable instrument that belongs in the kit of every serious planetary observer.
Technical specifications
| Parameter |
Value |
| Filter size |
1.25″ |
| Transmission range |
320-380 nm (ultraviolet) |
| Visible light transmission |
Very low (blocking) |
| Mounting |
Standard 1.25″ threaded barrel |
| Primary application |
Venus atmospheric imaging (CCD/CMOS) |
| Manufacturer |
Baader Planetarium (Germany) |
