- light pollution
Spectacular results with the RASA 8
I upgraded to these from 12nm Astronomik filters. Those were great filters for getting me started out and learning narrowband. However, when I got the RASA 8 and paired it with a QHY 268M, I needed some 2" filters too. Seeing that Baader released a new version of their ultra-highspeed f/2 filters specifically targeted for CMOS sensors, I decided to give it a shot. The increased definition I get from the much narrower bandpass (3.5/4nm) is absolutely stunning. The emission nebula jumps out of the background sky, and the noise pollution drops out of the background. I typically shoot at a star park that's located at the back of a baseball field. As a stress test of these filters, I decided to take some pictures while the lights were still on, making the sky glow furiously. Even then, these filters cut through the noise. The image I've attached shows a closeup of some nebulosity in the Pelican Nebula, with a simple STF stretch in PixInsight. The left image is with the lights on, the right with the lights off. Both are the exact same night, same telescope and camera, etc, at 240s exposures. These are single raw frames straight off the camera. Even with the massive light pollution from the lights (not even 200ft away from me), you can clearly see the detail separated from the background. In short, I love these filters and I'm working on getting their "standard" f-ratio (f/3.5+) filters ordered for my other scopes.