Baader Planetarium T-2 Prism Star Diagonal

Prism diagonals, especially those with high-quality glass like this one, are often preferred for planetary and lunar observing because they can provide higher contrast and sharper images. They are also generally more durable and less prone to surface degradation over time compared to mirror coatings.

The T-2 system is a modular standard that allows you to connect the diagonal directly to various telescope adapters, cameras, or eyepieces without relying on standard compression rings. This creates a more rigid, secure connection and helps you save precious back-focus distance.

Yes, this is an excellent choice for systems with limited back-focus. With an optical path length of only 38.5mm, it is significantly more compact than many standard 2-inch diagonals, helping you reach focus with a wider range of equipment.

BBHS stands for Broad-Band Hard Silver. It is a specialized coating designed to provide maximum light transmission across the entire visible spectrum while being significantly more durable and resistant to environmental damage than standard silver coatings.

The 34mm clear aperture is well-suited for most 1.25-inch eyepieces and will not cause vignetting with standard planetary or high-power observing setups. If you are using very large 2-inch wide-field eyepieces, you might experience some light fall-off at the extreme edges.