AKB

Inspired by this fabulous recently-posted image... ... I set out to do the same. Alas, cloud only afforded me 17 x 2 minute frames, with an ASI 294MC OSC and an Altair Quadband filter, on an Esprit 120ED. Oh, so THAT's why you need a mono camera, narrowband filters, 10 hours, and a good sky! Tony.

Looking good! Time to update your signature line! Tony

…if not one of the best scopes you can imagine??! 🙂

Of course, visual inspection is not a particularly good test. (In the weekend papers they have a children's puzzle section with "Spot the difference": 6 differences, ... I'm lucky to see four of them!) So I took both those images, subtracted them (adding a small offset) and multipled the result by 30... ...OK, it is correlated with the image, but I think we'd have to agree that the difference is really "in the noise". Tony

The first number is pixels, and the second, in parentheses and marked with the seconds unit (“) is the one you need. We are talking PHD2, here, by the way?

If you’ve entered the focal length of your guide scope into PHD, and it knows you’re guide camera pixel size, then the option of displaying the RMS error in arc seconds should be available. As a rule of thumb, an RMS error of less than half of your imaging pixel side is satisfactory.

Oh yes, definitely the right place. You can clearly see the Cygnus Wall at the bottom right. The image is rotated anti-clockwise 90° to the usual orientation. From the result of the second processing, and the wide FOV, it rather looks light you should consider calibrating with some flats. Tony

Flip mirror and zoom eyepiece are useful tools. Find it easily in the wide view, zoom in and keep centering, then flip to the camera.

You could, of course, increase its f-number by simply reducing the aperture. 😉 This is actually something which hyperstar users can do to improve star shape… not necessary, of course, with the superior optics of the RASA!

You’re not wrong there! There’s clearly a difference between: C11 at f6.3, ultrastar mono. 10 x 15 sec subs. 4m 30 sec of 10 second shots using 15" Dob and the ultrastar. plus, of course, the presence of the moon in the first one. Wish I had a telescope with me last night. It was warm and clear and looking great to the naked eye, but I was away from home. Typical! Tony

…so this one isn’t yours … ? 😉

Have you seen this thread? Possibly useful info there.

I suppose that 80 minutes is all one can expect in this part of the world, these days. Although, to be fair, musn't complain... Clear Outside showed all red for last night (3-Sept-2021) but there was just a bit of high cloud until the last five minutes of acquisition, and then, suddenly, woosh, it was all clouded up. At that time, the target was just reaching the meridian, anyway. Trying to correct the tilt/spacing issues with my field flattener, I rotated the camera 180º, just in case that helped. It didn't. Usual setup, for the time being: Esprit 120ED Mesu e200 mount, guided with RMS < 0.5" ASI 294MC OSC with Altair Astro Quad-band filter 16 x 5 min subs (for a total of 80 minutes) PixInsight / StarNet Was hoping to catch the jets of the Herbig-Haro 555 at the end of the pillar in the neck, but apparently this needs more data. Probably much easier in Ha, but OSC and a Quadband filter is what I have at the moment. Will try to add more later, although multi-night acquisition is something that I've rarely done. Trying to up the quality this season... although the large halos seem to be endemic for this type of filter, and I've chosen not to do anything to mitigate these for the time being. Tony

Thanks, but strangely, the key part of your message appears as black. HOWEVER, in the summary of the message, it *does* show as: pip install --upgrade jocular==0.4.7.dev2

OK, so the approved method is: pip install jocular --upgrade I think...? Ah ha! ... I always use it full screen, so never saw that!!

Good grief, this is a very good first image. I would be very pleased with that. A few suggestions: It’s black clipped, so maybe some of the weakest signal has been lost. It has a greenish tinge, to me. Easily removed. Colour may be a bit off, even after green is removes. Some colour calibration and saturation here? But really, really good, to my eyes. Tony

@Martin Meredith I see some recent updates on GitHub. What's the approved way of updating? (New season coming up!) Incidentally, it would be nice to have a place in the app where you could see what version it actually is? Perhaps it's there and I'm just missing it. Thanks Tony

I do note that the documentation for the RASA 8" says "~22mm diagonal is optimal", but I suppose that you simply had to test their statement "...can also be used with larger sensors up to 32mm diagonal, ... though some compromise must be expected at the image periphery." I believe that the 2600 has a diameter of 28.3mm. 1. I didn't think you did 'compromise' when it came to image quality? Or is this all part of the experiment? 2. In the same sprit, would you plan to push on up to 32mm? Anyway, good luck with this departure from the norm. Who would have thought it? Tony

You can, of course, rotate the optical tube in the tube rings until the focuser/eyepiece is in a more convenient orientation. Folk *do* use Newtonians for visual all the time. To make this a safer operation, you can have one additional tube ring clamped to the tube, but not the mount, which can act as a stop and rotate against one of the two rings fixed to the mount (and suitably loosened so that the tube can rotate.) Tony

Thanks. Yes, the 120 is very nice… you’ll need a bigger mount too!

Just for fun, I tried a Hubble-like palette... This seems to work quite well even though it's not really narrow band.

Saturday, August 28, 21:30 - 23:30. Moon rising and high cloud, with not very good transparency. I have a new mount which needs a meridian flip (Horror! not used to this) so I stopped before the meridian. I still need to tweak this setup to fix what is either tilt or wrong back-focus, or both. So this is a crop. Nevertheless, not too bad, I hope, for just two hours. Esprit 120ED Mesu e200 mount, guided with RMS < 0.5" ASI 294MC OSC with Altair Astro Quad-band filter 24 x 5 min subs PixInsight / StarNet Thoughts on ways to improve are much welcomed. Thanks. Tony

Yes, a very fair question! And in line with this comment too: Here's the history from PixInsight: SCNR – I see you did this anyway, but what I see now is a bit blue? Curves – to boost contrast and saturation Local Histogram Equalisation – at three different kernel radii: 32, 64, 128, but only in a small amount, around 0.1 Unsharp mask – standard deviation of 2, amount around 0.6 As you say: HTH Tony

@Richard_ I tried this, and hope you don't mind. You can certainly bring out details in the Pelican's neck and the Cygnus Wall. ...but is this pushing things too far? Tony