wimvb
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Everything posted by wimvb
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From the album: Liverpool Telescope
© Wim v Berlo 2017
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From the album: Liverpool Telescope
© Wim v Berlo 2017
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From the album: Liverpool Telescope
Messier 88 galaxy 9 x 90 s Blue 7 x 90 s Green 19 x 90 s Red Some of the frames are 120 s exposures Processed in PixInsight© Wim v Berlo
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Gina's Mini Dome Observatory for Widefield Imaging Rig
wimvb replied to Gina's topic in DIY Observatories
Yes, found it too: If you have a somewhat higher roof/lid, the scope can sit a bit higher as well, allowing imaging down to the horizon. But imaging to the north is more difficult. -
Gina's Mini Dome Observatory for Widefield Imaging Rig
wimvb replied to Gina's topic in DIY Observatories
How about this simple setup? Came across it in the indilib forum http://www.indilib.org/forum/general/1014-post-your-indi-setup.html#7313 Sure looks simple enough -
Gina's Mini Dome Observatory for Widefield Imaging Rig
wimvb replied to Gina's topic in DIY Observatories
Which is about the same size as an umbrella. I think that I would make ribs from plywood (4 semicircles), and cut the cover from alumium sheets. Just a thought. -
Gina's Mini Dome Observatory for Widefield Imaging Rig
wimvb replied to Gina's topic in DIY Observatories
Looks like a '70-s umbrella. Or: Cut one in pieces, then scale it up. How large is your obsy going to be, and what material? (sorry, you answered that last one already) -
A. Yes, but you probably only see the effect if the number of subs dropped is about the same as the number kept. Removing two subs out of a stack of 30, hardly makes a difference. But removing those out of a stack of 5 will. B. Yes again, if you dial in the correct kappa value. Adding a bad pixel map in lieu of darks also helps. As will other methods, such as cosmetic correction, which looks at each pixel neighbours in each individual sub, and then replaces it if it deviates more than a certain amount (again in units of standard deviation).
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That looks great! Glad you sorted out the problem. With a coma corrector (I use a baader on my 150pds), stars will look much better too. In phd, you can check how often dec was corrected. This will give you an indication about polar alignment accuracy. Cheers,
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From the album: Liverpool Telescope
My take on the little Dumbbell. Data from the Liverpool telescope. Processed in PixInsight.© Wim v Berlo
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Frank, have you tried running the PHD guiding assistent (under the Tools menu)? It will report the status of your setup. If there is backlash or the settings are off, the assistent will suggest what to do.
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Good luck, hope you get it sorted out.
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I know the feeling. Some time ago, I had a similar experience. I couldn't get polar alignment right, no matter what I did. Finally it dawned on my that I was stepping around on the soggy grass after winter, and my telescope actually bounced up and down every time I passed too close to the north leg of the tripod. This despite it being on fence-post-anchors that are driven into the ground. Sometimes it's those small annoying things that ruin a session, untill you figure out what it is. In the end, I gave up on trying to get polar alignment perfect and just went with it. Guiding was good and the images turned out ok anyway. I'm sure that if you come back another night, everything will run smoothly.
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From the album: Liverpool Telescope
© Wim v Berlo
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From the album: Liverpool Telescope
© Wim v Berlo
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From the album: Liverpool Telescope
© Wim v Berlo
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From the album: Liverpool Telescope
© Wim v Berlo
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From the album: Liverpool Telescope
© Wim v Berlo
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@mAnKiNd: Here's a pic with the focus settings of my scope/cc/camera. The line marked K20D is for just the camera. The line below is for camera with Baader CC.
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Welcome to sgl. Fyi, I use the baader cc with my 150pds, and it works great. Together with my pentax dslr, I didn't need any spacers. But the pentax has a little more 'back focus' than a canon. I wouldn't worry about guiding issues for any of the CCs, at the native fl of the scope it's quite easy to guide.
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Blair MacDonald had an article in the Canadian astronomy society's periodical about this. It's available online, and easier to read.
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Nice catch. The Rosette Neb will be a challenge for an unmodded camera. If you have the possibility to increase the exposure time and number of exposures, that will really help to pull out more detail. Otherwise the nebula will stay close to the noise floor. What processing software do you use. To enhance the nebula and keep the stars under control, you can use either Masked Stretch in PixInsight, of a similar technique in PS/GIMP http://www.nightanddayastrophotography.com/gallery/Processing.htm Especially nr 12: LMS (Layered, Masked Stretch) processing Thanks for sharing
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Alejandro Tombolini has worked examples at pixinsight.com.ar that show how to use the script. I use it after dbe and background neutralization, but before colour calibration, since it will affect white balance. Then I follow up with deconvolution of stars only, before stretching. If you mask stretch the V channel, you end up with plenty of colour in the stars.
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HSV repair script. It's under scripts -> utilities. You can combine them in the linear stage, or (masked) stretch the V before combining. Star reduction (morphology transform -> morphological selection) with contour mask can also give more star colour.
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Been there, done that. Nowadays my camera is always on RAW. Even when used as family camera. (Which it is less nowadays, as mobile phone cameras are so much easier.) Nice pic, btw. I'm not sure that calibration frames make sense when shooting jpeg, since the calibration process needs single pixel information, which is lost in the conversion process. Flats may work, removing vignetting. Bias and darks may deteriorate the lights due to added noise. There's only one way to find out ...
