1000 Oaks
LP-4 Hydrogen Beta
2.0"
RRP $185
For Sale for $115 ono
Posted anywhere in Australia
Technical Stuff:
Enhance your deep sky viewing with the latest in multi-layer coating technology. Our filters transmit desired wave-lengths in a very steep slope vs. gentle transition slopes in competitive brands. This means better contrast and overall performance.
This Thousand Oaks 2" H-Beta line filter for 2" eyepieces has a narrow 12 Ångstrom passband with very steep cut-off slopes centered on the nebula emission line of hydrogen-beta at 4861Å. This narrow passband blocks the rest of the visual spectrum, including light pollution, natural airglow in Earth’s skies, etc. The result is an extreme contrast between the black background of space and the delicately attenuated H-Beta light (about one-third the strength of H-alpha emissions) needed to view a few extremely faint objects such as the Horsehead, Cocoon, and California Nebulas that emit relatively strongly in H-Beta.
In many cases, an H-Beta filter is the only way to view those objects. The filter needs a steady, transparent sky; generally a 10-12" or larger aperture telescope; and a long focal length 2" eyepiece to get you as close as possible to a maximum-efficiency 7mm exit pupil for the best results in viewing these difficult “observing trophy" objects. It is not designed for astrophotography or for observing reflection nebulas.
Hi am interested in the filter. Can we talk on 0434-376-212. Need to manage 3 hr time difference as I am in the West. Yes, I also reolied to your other 2" filter AD.
