Search the Community

Hello. Recently I've been getting terrible-looking stars despite what looks like perfect collimation. All my stars look elongated. I will post pictures to help answer this question. I use a Cheshire eyepiece. My telescope is a SkyWatcher 250PDS. Thanks!

Hi, I have just recieved the last item which was on back order for a couple of months from USA. I already had the Infinity Eyepiece but was waiting for the BlackCat. Everything was ordered from FLO and i was very happy with their service. Instead of writing an essay, i made a video of how I use the tools and how they look, but in short - Theese tools are FAR superior to the Howie glatter, even with the Tublug. /Daniel

While doing darks, i realized one of the darks was a bright white. i was rummaging behind my newtonian w/ my headlamp on. Looks like light can pass thru the gap around the mirror?! What is the best way to avoid that?! Best, U.

Hello everyone, After impulse buying this 80mm refractor a year ago, being very underwhelmed and returning it, I've stepped back and done a lot of researching of scopes & astronomy (mainly online due to Covid19). Now that I have a little better perspective on things I'm looking to get my first "real" scope and would welcome some advice. A lot of things I read and seen seem to suggest an 8" DOB being a good beginner scope one can grow into, without breaking the bank. Thus I'm leaning towards the Apertura AD8 with a Barlow & maybe additional lenses down the road, but again I welcome any advice or confirmation that this is a good first scope for me and my family? Other details worth mentioning: Price - A definite factor as I have no idea how hooked I or my family will become with the hobby. Last thing I want is an expensive dust collector sitting in the corner of the room. Definitely under $1k, preferably closer to half. If we end up loving it and I trade up, so be it... Interests - Planets and definitely faint & DSO's for sure (so I think that rules out low cost refactors?) Aperture - I know this is the most important aspect and people tend to suggest "Go bigger", 10", 12"+, and I understand the trade offs, but have no practical experience yet, so this is a difficult decision. Price, portability & light gathering are all considered here and why I feel the 8" is probably a good first scope size? (feel free to weigh in here) Location - I mainly see this being used in our backyard, which thankfully is pretty private & dark but we do live in the suburbs and there are stairs to consider. Maybe we'll take it camping or drive to a secluded rural spot once in a while, who knows... Size - Similar to aperture giving more light, I read that 10"and above start to become heavy & unwieldy. I'm no weakling but my wife and kids may want to use this too and the backyard is down stairs off our deck, so factoring this in.... Astrophotography - Probably not yet... My wife's a photo nut and has a couple nice DSLR's already. However, this seems like an expensive & time consuming rabbit hole, plus I would think you'd need auto-tracking mounts. Things could change down the road but for now it's not something I'm really factoring in. One can always google celestial pics right? Manual vs. motorized - I really don't know. I've read the pros & cons, people seem to be on one side or the other, and again astrophotography isn't a big factor at this time, so probably manual.... I was somewhat considering NexStar 6SE as it's barely under $1k, but thinking a 6" will limit DSO capabilities? The 8SE seems nice but we're talking $1200+ for bare bones. Also an interesting conversation I had with a rep from highpointscientific mentioned an 8" DOB would be more blurry and have less color than an equivalent 8" SCT, which got me worried about a DOB and seemed to contradicted things I've read, but again I have no practical experience here. All I know is I bought a $200 scope off Amazon a year ago that could view the moon and bird watch. Saturn and Jupiter were blurry, shaky, white dots, forget about DSO's. I returned that 4.5 star hunk of junk and wanted something more. I hear great things about DOB's far as viewing, but I'm not going to find an accurate video online of what one would really see through it for obvious reasons. So here I am looking for advice. Would an 8" DOB be a good first buy? Would it genuinely be able to see the planets well along with many faint and DSO's? I know a 10" or 12"+ would gather more light while sacrificing cost and bulk, but are they that big of difference between being able to see DSO's and not vs. an 8"? What I would hate is to buy an 8" DOB and immediately think "I should have bought a 10" or bought a 10" and never use it as it's too much of a hassle to lug down the stairs & setup? So C'mon experts, please bring it! If you made it this far, thank you very much & you'll have good karma for many moons to come!!!

i am looking for a coma corrector for astrophotography, i have a skywatcher 254/1200 pds, a nikon d5100, and a skywatcher off axis guider, what would you recommend?

Hi, I want to place a CCD camera where the secondary mirror is, remove the sec. mirror completely. It,s a home made F5 14 inch. Do I have to use a coma corrector or/and a field flattener? Can I use a Barlow with a field flattener or coma corrector, can I use eye piece projection with a field flattener or coma corrector? Many thanks, Markus

Have you ever thought about why your Newton telescope has the dimension it has, primary and secondary mirror, focuser, f/number and so on? I stumbled in to this tool Newt-Web that Kenneth H. Slater has developed further from Dale Keller's code. It's an online design tool page for Newton telescope. It's a very intuitive page where you can put in some figures about a Newton telescope that you want to built and get back information about it's performance. It give a ray trace and important data back. From that you get understanding when a Newton telescope design is good or not. I have done some test and written it down on my homepage so you can see the different steps and my comments: http://astrofriend.eu/astronomy/projects/project-design-newton-telescope/project-design-newton-telescope.html I already know some of the physics and math, but never got to know so much in short time what happens when you change a parameter and what happens inside the telescope. Beware, I'm still in the learning process and not all what I have written is fully correct. I recommend you to take a look at Newt-Web page even if you never will built a telescope, you get knowledge and understanding that could be very valuable when you shall buy a Newton telescope. /Lars

Good day all, During the first half of June I worked on this 4 panel mosaic of the LBN 239, 241, 243 complex in Cygnus. Besides the bright component ic1318a it was a test for my new asi1600 on some fainter nebulae. I think the small cmos camera is holding up pretty good. Very little noise, I did not use any noise reduction in the post processing. The calibrated frames have been stretched and stitched together in PS. Details: Scope: 10" f/3.8 Newtonian CMOS: ASI1600MM-Cool @ -20°C Filter: Astrodon 5nm h-alpha Exposure: 20 hrs total (5 min subexposures binned 1x1); Unity Gain setting / 5h for each panel Resolution: 0.82 arcsec/pixel A higher res version can be found here. https://pietervandevelde.smugmug.com/Pics/Deepsky-1/i-MpNmG6t/4K Thanks for taking a look, Regards, Pieter

Hi all! Yesterday evening I finally was able to have a success with my new setup. Since february / march I have been struggling with getting autoguide up and running, but due to various mishaps and lots of bad weather, I haven't been able to produce a single image, up until now. This is what came out: M13. As you can see the stars are not very clean... So guiding apparently wasn't as good as hoped for... I also used flats, but there still is a bit of a gradient, but a lot less than previous. These are 180 sec exposures at 800 ISO, so I guess I have to be at least a little bit happy with this result, because without autoguide I could go up until 90 secs, approx. Any thoughts on what can influence good guiding? FWHM was around 5, so not perfect... maybe that could be better, but I never seem to be able to go below those numbers, and often in the past it was way higher... yesterday morning I wanted to set the focus point on the guide scope, so I pointed the moon during the day, and focussed it as best as possible, and marked that on the scope. this night, focus was in fact very close to that mark. But FWHM says it wasn't perfect... I also did drift alignment beforehand, and the guide error graph in Maxim was pretty nice, after initially having to redo the calibrate, because "guide star faded". There were no clouds, however, and the images from the guide scope showed good clear stars (I use a dew shield on the guide scope)... Any idea what this could indicate? I collimate every time, so that should not have been a problem either... Any thoughts much appreciated!! :-) Gerhard.

hi all, I was just reading up on optical aberrations, and it appeared to me that maybe my pics taken with my Vixen suffer from coma... It looks to me like the stars are all malformed, and maybe this is coma, very common to newtonians... Coma correctors can be a solution, as I gather, but backfocus issues might ruin this, if there is not enough room to focus with a corrector on. Does anybody know if my Vixen R150S can handle a coma corrector with a DSLR attached? or will I not be able to focus anymore, and so would have spent 160 euros in vain? I haven't found info on the backfocus of my scope... Any info would be great!!! Gerhard. ps: also anything you might have to say about my pics would be appreciated! :-)

Hi all, yesterday caught a good clear sky, so went out to observe. Had a lot of difficulty setting up the scope... On the first run it didn't want to complete the 3 star align, so I had to do everything again, and fortunately, afterwards it did align... Probably to do with poor PA... I had difficulty the first time aligning well with the polaris... So then I tried M1 (was low, and the photo did not turn out too well, so not posting), M64 and NGC 5033 (not processed yet). M64 came out like this without flats: and with flats: As in the last time, big problems with tracking and coma, apart from the flats problems (really have to get me a flatbox). The galaxy is not too bad, but the edges of the photo show terrible stars... Will have to try more and harder... I'm also thinking that in the end the place where I observed (close to home) is not near as good a place for dark skies, as the place from my last post (with M3, M81/82 etc), which is at an hour's drive... http://stargazerslounge.com/topic/240657-coma-problem/?p=2621703 Any thoughts? Any suggestion would be helpful... Thanks! Gerhard.

Hi all! I was just wondering about something, and would much appreciate to hear some opinions /suggestions... Premise: I'm just starting, very green, and very curious... With my f5 Newton and DSLR I have been getting some very satisfying results so far, apart from the expected coma and tracking issues. I was wondering if it was at all possible to have more magnification with such a setup, to be able to catch also the smaller DSOs... I have been told that those smaller objects are difficult in that one needs longer focals, and thus longer exposures, and thus better guiding. So, just slapping on a barlow between the tube and the dslr would only frustrate things, apart from focussing issues... Can anyone confirm this? This is obviously a long term issue for me, as at the moment, I'm quite happy with the setup I have, and the lack of funds for now puts any ideas I might have on hold. But for the future it would be very interesting to know what options there are for really far DSOs... I would definitely first of all start with setting up auto guide (not just for far DSO), so guide scope, guide cam and PC + connections and software. That's a big bite. Afterwards it would probably be: buying a purpose scope for deep DSOs, long focal, big aperture. SC? RC? A good APO? Opins? thanks all! Gerhard.

Hi all! Yesterday good weather, so had my first go at drift alignment with my new reticulated eyepiece. I took my time to figure out well the various steps in the right order, etc... At one time, pointing a star in the east, I think I overdid the correction on the Altitude, because the star started drifting a lot, so I started again from the beginning... As always a learning curve! :-) But I had fun doing it. It took me a lot of time, but finally I got to shooting some subs, and these are the results: M57 @ 38 second subs: M13 @ 63 second subs: The usual coma problem is visible, but I am nevertheless quite satisfied with this first try... The stars look pretty good, if not enlarged too much ;-) Opins? Any feedback would be appreciated! Gerhard.