16.08.2022 Imaging Lunt 60MT

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Tuesday 16th another hot day. Windy and cloudy at times. I continue to asses the quality of the Lunt 60MT etalon. Still within complete 60MT telescope with B1200S2 blocking filter and ASI174 camera fitted. I have the little Lunt in a tube ring mounted onto one of the 150mm tube rings.

It is now late and the sun has set behind the local trees. I'll post the processed images and add text later.

The little Lunt H-alpha telescope was on the wrong side of the 150mm telescope. Which itself was on the wrong side of the mounting. So reaching the focuser and tuning knob from the monitor was impossible. 

I set focusing to the sharpest I could manage and then tried tuning. Boosting exposure length produced large variations in brightness on the disk.

 I used this variation to retune. To achieve the most even and darkest image. The results are shown here.

The monitor showed the entire sun's disk as about 6" across. 912x912 was safer than 800x800 in capturing the whole disk within the SharpCap frame. I could then crop allow the disk to fill the frame.

 The image on the monitor looked completely stable compared with the hugely enlarged image I am used to seeing from the 6"/150mm telescope.

 The image did not look as sharp as I would have liked but focus was pretty close to optimum. N doubt the seeing condition were not ideal.

 I find the slow motion on the Lunt focuser very useful. Unlike the FT focusers on my larger refractors. The latter seem to be too slow to achieve very much.

 Yet again I was having problems with ImPPG. It instantly sharpened the AS!3 images to ridiculously grainy. So that I had to set Lucy Richardson to the minimum setting of 0.5. Raising this figure ruined any chance of a useful image.

 Once set to 0.5 I could only add the tiniest degree of change to the sliders before the images were ruined by over-sharpening.  

 There is something very wrong here but I have no idea what. The images should have been useful at the default settings. By default L-R should be at 1.0.

Of the four images I have processed and posted here, I think number 3 at 16.32 [UTC]is the clearest. The others show variations of texture and brightness across the disk.

 My apologies for the variations in orientation. The camera was rotating as I struggled to reach the tuning knob and focuser. I tried flipping the third image horizontally but that didn't help.

 In addition to the problems mentioned I had to reload SharpCap. It was refusing to record videos onto an almost empty SSD. I had to delete a couple of dozen earlier videos before it would behave itself.

 Both AS!3 and ImPPG could not find earlier processed images. In fact I don't even recognise the 3rd image in comparison with the others. It could only come from today or yesterday. Because I haven't been able to capture the full sun's disk until now. Very odd! 

  

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