Lunt CaK

Using the EQ3-mod, mountpusher, Baader Astrosolar ND3.8 Film, TS-Optics 76/342 TS76EDPH, automated filter wheel, ASI 178MM (cooled) setup, I imaged the Sun and obtained the following images. See also the The Sun on 2022-12-18 in Solar Continuum, first light article, today’s update.

Also, the heavy artillery Calcium did its job. The lack of high frequency details is due to having 5×4’33 smearing precisely those details away, favoring the large scale structures. EQ3-mod, mountpusher, Sharpstar 60/330 ED-APO, Lunt CaK B600 LS6CAKMDS2, ASI 178MM (cooled) (tovább…)

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.

(tovább…)