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There are cheaper solutions than Moonlite, if you feel uncomfortable spending £300. https://www.teleskop-express.de/shop/index.php/language/en/cat/c92_Okularauszuege.html This combination may be worth investigating: https://www.teleskop-express.de/shop/product_info.php/info/p3701_TS-Optics-Base-for-Newtonian-Focusers---fits-tubes-from-160-185mm-diameter.html https://www.teleskop-express.de/shop/product_info.php/info/p3700_TS-Optics-MONORAIL-2--Newtonian-focuser-with-Micro-Transmission.html Just check whether you need to drill new holes in the tube.

Not sure that will work with the stock 130pds focuser.

If that camera system allows for fast enough downloads, you may be able to collimate on a star with it. Or at least check collimation on a star (star test). If you then point to another star and collimation has shifted, you know it is the focuser that is to blame. Putting a £300 focuser on a £160 telescope may seem overkill, but you end up with a £460 imaging system that still may be good value for its money. That new focuser doesn't have to cost £300 either. I have the low profile SW Crayford focuser on my MN190, and it holds my ASI + efw + oag well enough. I doubt it costs as much as a Moonlite. Btw, you should also check the primary mirror support, to make sure that doesn't move. Another possible source of shifting collimation Just my €0.02.

Correct. There seems to be just a bit too much friction somewhere. There are no sensors, as I operate the winch by hand control (the yellow box in Göran's image). No automation yet.

Thanks, @RAR_MI_USA. The roofs are operated by one winch each, 12 V, 2000 lbs. The East roof will slide down on its own accord, but the West roof doesn't run as smooth, and needs help opening. During summer recess, I'll need to check that. I'll probably install rails and V groove wheels to make it smoother. In the future I may install an electric fence system to automate the roofs.

Doesn't the dew shield of the RH lens get in the way of the guide lens?

@Rodd do you have an observatory, or do you need to set up every time? This imaging season (since September) I've only completed two images, partly due to my observatory not being finished, but mostly due to the weather. But having an observatory means I can be up and running in a matter of minutes, and take advantage of even a few hours of clear skies. Without it, I'd probably have had no images at all this season.

Nice! The unusual framing of a common subject makes this an interesting image.

I don't know about you, but for me, tinkering with the gear and getting everything working is a major part of the fun. Several astrophotographers that I know, and have gone remote, still have a setup at home just for that.

That's the math behind it. But ap isn't just numbers. Rely on what you see. @Rodd, you've produced excellent images in the past from your location. I'm sure that in the end, this one can be added to that collection. But I must admit, since I moved to a mag 20.5 location, it has become easier to process the data I've collected. And I haven't had to rely on noise reduction as much as before.

Two options: Use a lp filter in stead of an L filter (this won't help with star fwhm). Collect lots of rgb and create a synthetic L. I believe you have already done this at times. Unfortunately, there is probably no shortcut. From a light polluted site, you need to collect more data. Btw, you may find this interesting: https://skyandtelescope.org/astronomy-blogs/astrophotography-benefits-dark-skies/

With starnet you can remove the stars from the image and the paste them back in from a less stretched copy. This will allow you to deemphasize stars as much as you like.

That's a very nice catch. This galaxy is also on my list, but with the weather the way it is, and imaging season ending late April, I don't think I'll get around to it this year. Thanks for sharing.

Light pollution is the most likely cause. For each magnitude you lose, you need 2.5 times as much integration time. If Göran @mag 21.3 collects 1 hour of data, then at mag 19.3 (2 magnitudes), you will need more than 6 hours of data (2.5x2.5), to get the same noise level. Personally, I would put that time in luminance and not rgb. You can blur the colour before lrgb combination to get rid of the noise.

I have found that with my ASI174MM-COOL, and MN190 (f/5.3), I need at least 3 - 4 hours of luminance to get a decent background, with 120 s subs. Ie, at least some 100 - 120 subs. Colour is more forgiving, but 40 subs (@240 s)/channel is a minimum. Colour can always be blurred before lrgb combination to suppress colour noise. But all this is very individual. The total integration time that you need not only depends on optics, but also on sky quality.

Looks like a good start already.

Well, after 25 hrs spent on this image, it seems you're up and running again. Great image.

That turned out pretty good, despite the lost data

But only those that are visible in the final image count, of course.

Simbad, at the university of Strasbourg http://simbad.u-strasbg.fr/simbad/sim-fcoo I got much info on those faintest of fuzzies when I posted a galaxy image on astronet.se

The galaxy marked pgc 2640520 is the brightest member of a galaxy cluster, consisting of some 28 galaxies. Most of the reddish fuzzy pixels surrounding that galaxy are its sibblings. And just for kicks: that galaxy has a redshift of 0.219, putting it at a distance of about 2.9 billion light years.

Nice start of the galaxy season, Göran. PI isn't particularly good at finding all the galaxies, so you may well have triple that number of galaxies in your image

While your camera has a 12 bit analog to digital converter, your files are 16 bit. This means that you either only use the lower range of those 16 bits, where white = 4095 (2^12 - 1), or the high range, where white = 65535 (2^16 - 1). In this case, 1 ADU = 16 DN. Better check this first. Then set the flat exposure time to somewhere in the middle of this. With the reducer, exposure time should be a little shorter, because each pixel receives more light than before, as it covers more area.

Thanks. So far, I've never had a problem finding a guide star. I use the ASI120MM-S as a guide camera. Normally I bin this 2x2, but for some reason, it was set to 1x1 with this image.

I will do some research. My previous image had a galaxy cluster that is 5 600 Mly distant. Light that left those galaxies has travelled longer than 1/3 of the age of the universe.