Cloud Break Optics

2" Venus U-Filter (BPU2)

2" Venus U-Filter (BPU2) - Main image
$237.85 $355 In stock

Category: Filters

Description

The Baader Venus filter blocks the entire spectral region from 200nm to 1500nm except for a very narrow bandwidth from 300nm to 400nm in the far violet. Transmission efficiency reaches 80% at the peak. This filter makes it possible to image cloud detail on the surface of Venus.

Please Note: The Baader U-Filter is specifically for digital imaging (digital SLR, webcam or CCD). Since visual perception stops at about 400nm (380nm if you're lucky), the light transmitted through the filter is not detectable by the human eye. Do not purchase this filter for visual use! Also note that the colors in the photo at left are the true reflected colors of each side of the filter and are the result of the different dielectric coatings used on each surface.

The accompanying photograph of Venus, taken by M. Rietze just 2 days before transit, shows the cusps enclosing two-thirds of the planet's circumference.

Extended Transmission Curve

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Standard Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

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United States · Return window (days after delivery): 30. Return method: By mail. Return postage: Seller pays.

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Customer Reviews (4.6 / 5 · 5 reviews)

Jacob ★★★★★

Finally got this filter to cut through light pollution on the Orion Nebula, and the 80% transmission made a real difference in brightness. The 300-400nm bandpass is narrow enough to really suppress city glow at my suburban site. Easy to thread into my 2" diagonal.

Aurora D. ★★★★★

The contrast on Jupiter’s bands popped like nothing I’ve seen before—that 300-400nm window really isolates the detail. Even with seeing conditions being average, the image stayed crisp and the 80% transmission kept things bright enough to enjoy.

Ruby ★★★★★

I was worried about how narrow the passband would be, but the blocking from 200nm to 1500nm is incredibly effective—it cuts out all the light pollution I had issues with before. The violet-only view of Venus is surprisingly sharp and clear with my scope.