I joined Damian in his garden in Streethay to observe the solar disc today. Interesting to compare my very amateurish drawings with Roger’s amazing photos in his post from his session with the sun today! Still, it was great fun.
I think that Damian intends to add in his own post soon – his drawings were amazing…..the artist at work puts me in the shade!
Both Damian and I have Daystar Hydrogen Alpha filters for observing the sun and I also have a Daystar Calcium-H filter. The latter performed really well today showing up substantial white haloes around the sunspots and also in the area of the filament in Roger’s photo. I have tried to capture these white areas in my drawing of the Calcium-H view. That filter does not show the prominences – the H-Alpha filter is required for that.
The drawings below were all drawn at my telescope:
- Sky Watcher Equinox Pro 80mm on Manfrotto mount
- Daystar Hydrogen Alpha and Calcium-H filters
- Televue Plossl 32mm eyepiece
- Baader 8-28mm zoom eyepiece
At the science day today, (see http://roslistonastronomy.uk/rosliston-forestry-centre-science-day-5-5-2018), I tried using my Daystar Quark Calcium-H line filter today with my Sky Watcher Equinox Pro 80mm telescope. Although the filter showed the disc well, it did not show up the (rather small) sunspot present on the sun today, nor any prominences. Granulation was obvious.
My feelings so far are that visually the H-line calcium filter helps the disc to be more visible BUT not necessarily showing up more detail – perhaps that needs a camera? Mind you, my experience of using the filter is limited so I might be wrong……
Certainly easier to see the disc of the sun than when I tried in past with calcium-K PST.
Peter (Hill) – how are you finding your Baader calcium filter?
Had a go at calcium-H line observing today for first time. Still using the same Sky Watcher Equinox 80mm Pro refractor that I use for the hydrogen line observing – both calcium-H and hydrogen line filters are Daystar Quarks and both bought second hand. My initial experience of using this calcium-H filter was a tiny disc in the middle of the lens with my Televue 32mm Plossl. I also had difficulty bringing it to focus even when only using 1.25″ diagonal. The hydrogen Quark is fine with the 1.25″ diagonal in this scope.
I added a Televue 2.5x 1.25″ Barlow between the diagonal and Quark calcium-H and now I could bring the image to focus – and it was much bigger as you would expect. In fact, I have contacted Daystar and they tell me the hydrogen Quark has an integral 4.5x Barlow lens so to match the same magnification with the Calcium Quark requires a similar Barlow and there is no integral Barlow lens in this filter.
The image is blue rather than red – and I agree with Daystar that this calcium-H image is much easier to see than calcium-k images I have previously seen in other people’s scopes.
There was even a sunspot for me to observe! I could not see much detail – I suspect poor seeing – I was looking at the sun in blue patches between clouds and some rain drops at times.
I could not see any prominences today. These are supposed to be far less obvious with the calcium-H filter than with the hydrogen filter.
The pictures below show me at the telescope using this new filter. Damian should be pleased to see that I following his advice re balancing the Manfrotto mount.
I had a go at photographing the disc and sunspot using handheld Samsung S7 phone – this has turned out to be MUCH more difficult that with the hydrogen filter where it works suprisingly well, as Damian and I have shown in previous posts. I guess this is due to much lower contrast. If you look carefully, the sunspot is visible as vague dark spot on the images – it was much clearer visually. I have also included a enhanced version of one of the images to shown the sunspot more clearly – but don’t expect to be able to see any detail! I think this filter is going to be a good candidate for my Watec-120N video camera – when there is clear day I will try this out.
The following pictures taken with handheld Samsung S7 are awful! When I previously did the same thing with the Quark hydrogen (not today) I got some good prominences – not sure what has caused this problem.