Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

stargazine_ep24_banner.thumb.jpg.56e65b9c9549c15ed3f06e146fc5f5f1.jpg

joecoyle

Members
  • Content Count

    240
  • Joined

  • Last visited

Community Reputation

90 Excellent

2 Followers

About joecoyle

  • Rank
    Star Forming

Profile Information

  • Gender
    Male
  • Location
    South Manchester, UK
  1. More maths - I know RMS means Root Mean Square and is some calculation of something and is measured in px. What I haven't found yet is the magic number for what the value should be... RA and Dec should be X, and the total should be under Y. What also confuses me is PHD's guide trend lines that show PA error (in a different unit to RMS I think) when doing a drift align... sometimes I can get it really good (less than 5, sometimes 0.1) and sometimes its like 25/30. Smallest tweaks of the knobs are given to make it swing wildly and the trend lines move a lot in the opposite direction. Is that just teeth on the gears not finely tuned enough to give me that control? I'll certainly keep refining - I agree there is more to do yet before giving up. That and I've spent far too much for this setup to be a pretty ornament in the garden. Yes whilst the guider is settling, the imaging camera is not taking pictures. I will do some research into dithering and what SGP will allow for - I've always considered it too advanced for me and wanted to get the basics sorted first. Sorry for rambling on. I know its all in the documentation somewhere. Joe
  2. Yeah PixInsight usually does a good job at removing the trails, I meant I just hadn't gotten around to it yet The images from early on I would say are fine (no worse than other nights), later on, they are quite egg shaped. It could have just been bad luck. I want to see if its possible to get 10 minute exposures for example, rather than sticking safe with 5. I agree look at the images first then the graph is a good mantra, but I just want to get the graph as flat and as I can... it seems everyone else has nice flat graphs so it makes me wonder If I've messed up on the simple things along the way... My mount is no way near mechanically perfect nor will it ever be, I really don't fancy taking it apart, so I will have to accept certain limitations. I've always been relatively happy with the images I get. But there's always room for improvement Cheers
  3. Hi, I've not stacked them yet, 10 of them had Starlink trails in... thanks Elon. But here is a single 5 minute Luminance from the start of the run... and here is one from the middle of the run, when the guiding was shocking: Noticeable differences Joe
  4. Hi, I just found these settings in SGP: Dithering is off, but it seems as soon as the guider reports under 0.3px then guiding will 'be considered settled' and resume immediately... Is this what you mean by too stringent? Is it better to have a few seconds in the For box to let it wait? How many is a few? Or increase/decrease the settle at value? There is so much maths in all of this, my head hurts. My mount does have PEC, but I've been too scared to use it... the Celestron book isn't very clear in how to do it, it seems to suggest it needs to be run run every time I turn the mount on... (currently though, I hibernate it every night, so it keeps its alignment and time) so maybe I just run it once and as long as its only hibernated it should remember it? Thanks Joe
  5. How do I get to see the cal ? I’ll post it in here... I will double check that the backlash comp isn’t on in both places. I tried Dithering in Sequence Generator Pro once. And then gave up. I’ll check it’s off. settling settings? Didn’t know there were such things. The only things I tend to change are the Hysteresis amount and minmo and guide direction. I read something the other day that mentioned bumping the exposure to 2 secs so I’m willing to give that a go. Its been the clearest nights here this week in months. I hope I wasn’t chasing the seeing otherwise I’ve got no chance. thanks Joe
  6. Hi @michael8554 Yeah that sounds about right. It’s been a long time. My setup is permanent in my observatory. But, does this mean that it’s time for a new calibration? Before the permanent setup I used to calibrate every night i imaged. Maybe I’ve gotten a little too lax in doing that. My camera and scope haven’t moved orientation in a while, so I’ve always just assumed the calibration would still be ok, but who knows? At this point I’ll try anything. Is it not the case then that observatory and permanently setup scopes should save and reuse a calibration? Or only for a few months at a time? Maybe a year is pushing it Cheers Joe
  7. Hi, Last night I had some particularly shocking guiding. Its made me think whether I should invest in a better setup? Or if i'm just limited by my mount? (I know that the AVX has a bad rep for dec backlash) Currently, I have an Orion Magnificent Mini Auto guider and 9x50 guide scope. I've attached a screenshot of the log viewer & the log also, as I can never make heads or tails of all the maths. If someone would be willing to dive in and see if they can, I'd be very grateful. Is it an equipment problem? Or is it just that my PA is rubbish? Would a better setup improve things? A pole master maybe? No amount of drift aligning / guiding assistant makes any difference. I read a PDF once about all the different graph patterns - saw tooth, stiction etc, but can never seem to improve things... just keep banging my head against the wall. Cheers Joe Start of the night: Later on: Log: PHD2_GuideLog_2020-04-24_215344.txt
  8. Hi everyone,I took some fresh bias frames (200) yesterday, with my Atik 414EX mono, at -20 degrees. I followed Kayron's tutorial here: Light Vortex Astronomy on creating the master/superbias. His superbias looks nice and smooth, noiseless. Mine looks odd. I'm not sure it is odd, or just me. That nasty great black bar seems strange to me. Here is the stacked 'master' bias: Here is the superbias (I reduced multiscale to 6, per the tutorial) stretched in 24 bit mode: Has anyone had similar experiences? I did them in the afternoon, so it's possible some light got onto the sensor I guess. Is it worth retaking them?Is there a quick way to compare? I calibrated the same master dark with my old superbias and this new one, then calibrated the same light sub with the master dark. There was no noticeable difference, but then I'm not sure how noticeable it would be? Sorry for the barrage of new questions in such a short space of time. CheersJoe
  9. @tooth_dr brilliant thanks for the explanation - I had totally forgotten about dark flats too Yeah I've been reusing these old darks for far too long - about time I redid them and my flat box is still in its box - a Christmas present from 2018. Been too scared to use it, as I always thought parking the mount at the end of the night meant all the dust moved around inside making flats pointless. So I never bothered as I value my sleep too much to be taking them at 3am when the mount is still tracking the target Now I have a permanent setup now with my mount on a concrete pier and I have no plans to rotate my camera anytime soon, so I should be able to take flats the following day do you think? Just point the scope up and rest the flat panel on it? I'm told as long as the camera orientation does not change, I should be good to go... Thanks Joe
  10. Ahhh major idiot moment. See when you say it like that it makes more sense - of course there is no light, so why would colour count - d'oh... Misconception number 2 on my list My brain is melted after trying to read so much around it. Im guessing temperature does matter though - I'm cooling my cam down now and its at -13... The shed is quite warm though, so I might wait til later to get it down to -20. I've been following Kayron's excellent tutorials at https://www.lightvortexastronomy.com/tutorials.html and whilst they are super detailed and informative, sometimes I get lost. How many flats per filter do you take? Just 1 or several and stack them into a master flat? Kayron suggests several of each filter and making a master. Dare I throw binning into the mix? Cheers Joe
  11. Hi, I'm determined to start to make more of my imaging so I am trying to build up a list of all the calibration frames I should take (and probably forgot to take from day 1)... thus far I have only ever taken bias / darks with the luminance filter. As I have a mono camera, do I need bias/darks for each colour too? Thus far, the best sub lengths I can get, are 1 minute, 2 minute and 5 minute. So I originally went for a stack of 50x4 minutes & made a master dark, and PixInsight seems to handle scaling it up/down. No idea if it's actually any good though. Now, I'm thinking I need to redo it - the cameras been moved around a lot in the obsy since then. Table time... +-----------+------+----------+----------+ | Filter | Type | Length | Quantity | +-----------+------+----------+----------+ | Luminance | Bias | 0.0001 | 200 | | Luminance | Dark | 1 minute | 50 | | Luminance | Dark | 2 minute | 50 | | Luminance | Dark | 5 minute | 50 | | --- | | | | | Red | Bias | 0.0001 | 200 | | Red | Dark | 1 minute | 50 | | Red | Dark | 2 minute | 50 | | Red | Dark | 5 minute | 50 | +-----------+------+----------+----------+ Am I right in this? Or totally off the mark? Do I need to do the same for Green/Blue / all my narrowband filters? Do I need a flat per colour / per length too? I can edit the table as we go, so I'd appreciate any help in filling it in /expanding it Thanks Joe
  12. Hi, It's been a few months since I last used my camera in earnest. It's in a roll off roof observatory. I have noticed some weirdness (two triangular patches on each side). Can anyone tell me what it is? It looks like condensation or some such to me, and gradually fades over about 5/10 mins. But I've never noticed it before. I don't think it causes any issues in imaging. I have a dew heater on the objective lens, so could it be on the sensor? Is it normal and I'm panicking over nothing? Thanks Joe Later on - much reduced:
  13. Oh. I thought parking the mount would count as moving the camera too as dust could move during the park. major misconception on my part then d’oh!!! i do have a permanent setup. Got a roll off roof shed obsy. :) I might be more confident about giving flats a go now then! Thanks Carole & Ray
  14. Yeah - I just noticed a nasty great dust doughnut on my Leo triplet! So this is my dilemma - last night for example, I set a sequence going (it was 11pm before the triplet came into view, and thought oh, nice clear night, I'll let it run til 3am.)... at the end of my sequences, my mount is parked and camera warmed up. Because of this, I can never take flats because the mount has always moved home... unless you mean don't park the mount/warm the camera, and get up at 3am and take them then? I value my sleep far too much Joe
  15. Oh. Maybe not just a quick try it out then Flats is a whole new topic - I got a flat box light panel for Christmas 2018. Never once used it. Don't even know where to begin
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.