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.