What is the main advantage of the Baader T-2 BBHS Mirror Diagonal's coating?
The primary advantage is its hybrid silver and dielectric design. It uses a BroadBand Hard Silver (BBHS) base for maximum reflectivity, especially in the red spectrum, resulting in brighter images. This silver layer is protected by a durable dielectric overcoat, preventing tarnish and making it as resilient as a standard dielectric mirror.
How does the T-2 system benefit my setup with this Baader diagonal?
The T-2 thread system provides complete modularity. Instead of fixed barrels, you can attach any T-2 compatible accessory directly to the diagonal's body. This allows you to:
- Create a rigid, flex-free connection for imaging.
- Minimize the optical path length to save precious back-focus.
- Adapt the diagonal for use with 1.25" or 2" nosepieces and eyepiece holders.
Is a mirror diagonal like the Baader BBHS better than a prism for my telescope?
It depends on your telescope. For Schmidt-Cassegrains (SCTs), Maksutovs, and other long focal-ratio telescopes, a high-quality mirror diagonal like the BBHS is ideal, as it introduces no chromatic aberration. For very fast refractors (f/5 or below), a prism diagonal can sometimes offer slightly better contrast and correct for minor spherical aberration, though the BBHS mirror's superior reflectivity remains a significant advantage.
Will the Baader BBHS diagonal work for H-alpha imaging of the Orion Nebula (M42)?
Yes, absolutely. The BBHS coating is specifically designed to have enhanced reflectivity in the red end of the spectrum, which includes the 656nm H-alpha line. When imaging emission nebulae like the Orion Nebula (M42) or the North American Nebula (NGC 7000), this diagonal will transmit more of the critical light to your sensor compared to standard coatings, resulting in a stronger signal.
Does the silver coating on the BBHS diagonal require special care?
No. While unprotected silver tarnishes easily, the Baader BBHS mirror is sealed with a hard, protective dielectric overcoat. You can clean it just as you would any high-quality dielectric mirror, using standard, safe optical cleaning techniques. The overcoat ensures decades of high performance without degradation.
Can I use 2-inch eyepieces with the Baader T-2 BBHS Diagonal?
Yes, but you will need the appropriate Baader T-2 adapters. The diagonal body itself has T-2 threads. To use 2-inch eyepieces, you would typically add a Baader T-2 to 2" ClickLock or similar eyepiece holder to the output side of the diagonal. This modularity allows you to configure it for any standard.
