Antlia UVENUS filter, model 31.75mm

The Antlia U-Venus filter is designed to image the cloud structure of Venus and Jupiter with CCD cameras on a telescope. Cloud details are reflected in the ultraviolet band, which normally cannot be captured with broadband filters.

The U-Venus filter uses the latest dielectric coating technology to achieve high transmission efficiency and exceptional UV isolation. The Antlia U-Venus filter blocks contrast-damaging frequencies above 400 nm that normally obscure ultraviolet details in sensors.

Like Antlia LRGB filters, the U-Venus filter minimizes halos around bright stars and increases contrast.

Recommendations for use

When using the Antlia U-Venus filter in a planetary camera, it is strongly recommended to remove the UV-IR protection, as this filter can attenuate the transmission of the ultraviolet band containing cloud details.

The lower the frequency in the ultraviolet band, the longer the exposure will be to obtain sufficient signal in the image. The sensitivity of most sensors also decreases rapidly at shorter UV wavelengths.

It should be noted that when using a digital SLR to photograph flowers in the ultraviolet, the camera must be specially modified to remove the infrared cut-off filter inside.

In non-astronomical uses, lighting conditions can block ultraviolet transmissions, for example UV with flash, due to a combination of weaker emission at shorter wavelengths and higher absorption by the flash glass. These factors combine to require a significant increase in exposure (for continuous UV sources), UV intensity and ISO sensitivity as wavelength decreases.

Non-astronomical use

The U-Venus filter can be used for all types of photography in the UV range (plants, insects, medical and scientific imaging).

Technical specifications:

• Lens type: Optical
• Mounting diameter 31.75 mm
• Substrate thickness 2 mm
• Transmission >80%
• Anti-reflective, anti-halo treatment