Update 2022-12-19, see below.
EQ3-mod, mountpusher, Baader Astrosolar ND3.8 Film, TS-Optics 76/342 TS76EDPH, Baader Solar Continuum 7.5 nm 1.25″, ASI 178MM (cooled)
While the weather wasn’t favorable at all, passing clouds and worse than average seeing in general, I have my first impression about Baader’s new Solar Continuum filter, which is, as I count, the third (an older friend says it is the fourth) generation: there was the first, letting IR through, then the double stacked IR-blocking version, and then this, 7.5 nm version from 2022.
On the one hand, it does its job. Given the atmospheric circumstances, the fact that I use a good quality apo and the low magnification, full disk image, I didn’t expect much anyway. My optics are already good, the weather suck and I seldom hunt small details. On the other hand however, this is about as good a solar image as I got from the ZWO Duoband filter — and this actually surprised me in a way.
With my setup, and the Sun this low (winter solstice is coming), the s7c (solar continuum 7.5nm) needs about 4-5 ms to get 90% saturation at zero gain, and the duoband ten times less. Other than this, I saw basically no difference on the live view, zooming in to 100% for focusing etc, for a few minutes I kept switching between the two using my automated filter wheel.
Having been imaging the Sun for quite some time now, and having done comparative tests going through several filters in one session, such as in this article, I can say that this is a nice filter, a welcome in my filterwheel and toolbox, but after the duoband, at least in full disk observations, it doesn’t really look like a step up. So for those of you pondering whether to do this or that, consider giving the duoband (or any comparable narrow band deep sky filter) a try, and who knows. The duoband has been my friend ever since I got this weird idea to use it for solar imaging.
The processed and oriented disk image in its black and white form, without emphasising the brighter-than-their-context features.
And the false color version, with context-aware emphasising.
Not ideal, perhaps even unfair to test filters – no cloud in front of the Sun while imaging though.
Live view, through the duoband filter, notice the exposure time
UPDATE 2022-12-19: so I felt like being too sloppy even for an amateur, be this hobby of astrophotography-without-actual-astrometry as artistic as it is. Because today was an almost clear sky, I recorded some more images to get the gist of this filter and provide a proper comparison. I managed to record 2×4’33 with the Baader s7c and another 2×4’33 with the ZWO DuoBand. Each recording got its best 500 frames stacked, and then the two tiffs were stacked together again. Below my results. Long story short, though the air/seeing could have played a role here, it’s winter solstice after all, the Baader s7c filter probably performs visibly better.
