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Ceph and Cass

Saturn June 8th after a lot of help


DrRobin
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Hi,

After taking on board all of the advice, 60% histogram, focus on Spica, etc, I managed the following:

post-10602-0-01671600-1370811505_thumb.j

Taken with a C11, DFK21, 2x barlow. Gain 876, 19th sec exposuse, 5000 frames, 40% stacked in AS2.

Robin

Edited by DrRobin
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Hi,

I made a comparison of various frame percentages to see how much difference there is in the final stack, not as much as I thought there might be. All of these have had the same wavelets and filtering applied.

Robin

Saturn-8-6-13-G874-E19th-2x-Frames.jpg

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Thanks guys. Stephen, I started in night time in Jan 2011 and then started white light solar for the Venus transit last year. I have just been a lot more active in solar recently. Mind it takes up a lot of time if you image both on the same day (like last Saturday) and this usually follows, clear sky in the day and clear at night.

Robin

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Really nice shot Robin, coming along nicely.

Nice few rings showing up now, maybe a bit of adjustment with contrast & brightness & a tweak upwards on the Hue.

I know what you mean about the percentage stacks not showing a lot of difference, i have still found 20-30% is a good bet but depends on the data.

You should be happy with that Robin.

Oh btw you can give me some tips when i get a PST if you like :-)

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Excellent results Robin, the comparison with percentages of stacked frames was surprisingly in the degree of uniformity - I think at a pinch 40% may just have it, but my glasses need a good clean ;) I've noticed much more pronounced variation with my mono results, but have had very poor seeing of late - I generally only use 25-30% of my frames from a stack on 6-8K, but have resorted to using PIPP to combine 2-3 successive captures on Blue channel (18-24K frames), then sorting the best 10-15%. I think an ADC would make the most difference on these low elevation objects and saving up to buy before the next Jupiter apparition!

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Thanks guys.

Jake, I agree somewhere below 40% is probably best. I might try a 10, 20, 30% stack next. I have had a lot of help from here and I have to say it has helped, even if i was bit late for Saturn. I had a look at ADCs, boy are they expensive, think I am more likely to take the mono route and fix in software. I have been thinking about a cooled mono ccd so he filters and wheel will also see some service for planets.

Ewan, PST, sure thing, any help you need just ask, I can't confess to be an expert like Montana, Peter Drew or MarkT , but I would be glad to help out. Watch out though, my misses thinks I am obsessed, what with solar by day and planets and galaxies by night.

Robin

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Just as a aside. personally ive experimented focusing on Jupiters moons, which I believe would be better as less movement will occur than from a star. But even then, ive found it can be tricky to be absolutely certain your in precise focus using stars or moons..

I found the best way, was to focus on the planet itself. Even Saturn that has less markings can be focussed on quite well using the cassni as a sharpness guide. A good way is to get it close, take some shots after you think the Cassni division looks sharpest. Then continue slight focusing in the same direction, take some more shots. by the time you have done this 3 or 4 times you've likely nailed it somewhere. Often ill spend ages looking at the Cassni. Then fine focusing some more to see if the Cassni has sharpened any.

Often it will. The tricky part is deciding if your in focus. or if it could do with another tweak forward. But if your shooting these focusing tests, even if it goes out more ( overshooting ) Then you will have captured some shots very close to focus. I never focus once and leave it like that. Bad idea. All your eggs in one basket. Yes you will waste a lot of time on focus, refocusing a lot. But whats better one super sharp shot or 10 slightly out. Hope my thoughts help in some way

Well done on the top image. once you've mastered the focusing. its just seeing that will determine the quality. As long as collimation and cooldown are good

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