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.


Joel Shepherd

  • Content Count

  • Joined

  • Last visited

Everything posted by Joel Shepherd

  1. I’m interested in learning about EVAA for outreach, but as an astrophotographer ... it’s not as interesting to me personally. It’d be more of a thrill to see a couple gray blobs and know it’s M51’s photons impinging on my own eyeballs. Whether that thrill is worth the cost of a big Dob ... hmm.
  2. Thanks @Paz and @Piero: I appreciate the first-hand experiences. It'd be cool to have a big scope ... but I'm not it can really be justified given our sky conditions. Good food for thought.
  3. We live under Bortle 6 skies (18.6 on the SQM). With a 4-6” reflector or Newt, we can see open and globular clusters, the Ring and Dumbbell, Andromeda, etc. I’m wondering how much difference we’d see with a 14-16” Dobsonian. Would there be noticeably more detail in the clusters. Could we see some of the smaller, brighter galaxies (M51, M63 etc.) Does the aperture make that much of a difference under a fair amount of LP? Interested to hear others’ experiences. Thanks — Joel.
  4. I have an Esprit 80mm and ran it on an AVX for about two years. While I can't compare it to the Explore Scientific, I will say that the Esprit is a no-muss no-fuss scope. It works well for imaging, it produces nice stars without color aberrations, has a decent focuser on it and one which is easily motorized if you want to go that far ... it's a keeper. It actually worked just fine on the AVX. The main issue I had with the AVX -- and I think this was mount specific and not a general AVX issue -- is that periodically, typically after an hour of guiding, the mount would suddenly veer way off on the DEC axis, guiding would fail and I'd have to manually get things going again. Not the end of the world, but it meant I couldn't go to sleep. ? But otherwise, I enjoyed two good years of imaging with the Esprit 80 and AVX, and while I've since retired the mount, the little Esprit is here to stay.
  5. How bad is your LP? If you look up on a clear night, what's the magnitude of the dimmest stars you can see? I can see magnitude 3 or 4 under our skies and have never felt the need for an LP filter. My personal preference would be to not use one: it would inevitably filter out some of the light I do want as well as light that I don't.
  6. An ED80 APO will take you a long, long way (and can also be delight for visual). I've had a SkyWatcher Esprit 80ED for almost three years now and it continues to produces better and better results ... rather, my skills continue to try to catch up with its capabilities. It's true that it is not the best instrument for small galaxies and planetary nebula, but for larger nebula and medium-sized galaxies or galaxy clusters it sings.
  7. @Anne Spretty much said what I was going to stay. Use star alignment to get the mount oriented so that go-to's are fairly accurate. I'd use at least three and as many as six stars. I never understood calibration stars either: you don't need them so just ignore them. Once you've done star alignment (and assuming you set down the mount roughly polar aligned to begin with), then do the ASPA. Follow the directions on the handset closely. Now ... after you've done the ASPA, you may want to repeat the procedure because you've changed the position of the mount. I would park/home the mount, turn it off, wait 10 seconds, turn it on, redo the star alignment (because, again, during ASPA you may have moved the mount significantly), and then redo the ASPA. At that point, you should be dialed in. Also, consider getting a reticle eyepiece like this: https://www.amazon.com/Orion-8450-Illuminated-Telescope-Eyepiece/dp/B000J5OTBM/ref=sr_1_11_sspa?ie=UTF8&qid=1541394002&sr=8-11-spons&keywords=orion+eyepiece&psc=1 Yes, it's pricey; yes, there may be cheaper ones and it's fine to get a cheaper one ... but having illuminated crosshairs to help center your alignment and ASPA stars will help more than you know. Finally: don't give up. It amazes me that you were persistent enough to align a motorized CG-4 well enough to get 3 minute exposures. I had a similar set up and never did better than 15 seconds. So you have the persistence and ability. Go slow, and aim for repeatability. Master the star alignment routine and then enjoy a night of observing. After that, master star alignment and ASPA -- so you can do it without much drama night after night -- and enjoy more observing. Then do it and add a camera to the mix. Get comfy with 10-15 second exposures. Then add a guide camera to the mix. Figure out how to get it focused, get PhD calibrated, etc., and go for 30- to 60-second exposures. Etc. The goal is to get to the point where each of these things is very mechanical and predictable: where you repeat the exact same steps every night and get essentially identical results. It takes patience, but if you take a deep breathe and don't try to move too fast, with your persistence I'm sure you'll get there.
  8. I've used both and really wanted to use APT because I find its user interface much nicer but ... two things made me bite the bullet and commit to SGP instead. One was auto-focusing: it was slow in APT and relatively quick in SGP. If you have or plan to have an autofocuser, I think that's a point for SGP. The second thing was meridian flips, which was my whole goal in getting automation software. I want more lights and more sleep! ? ATP, unfortunately, does not support fully automated meridian flips. SGP does, and once you have it down it is almost magical. Start your sequence, hang out for a few exposures to make sure things are going okay, and then call it a night. Wake up in the morning to a whole new set of lights and a telescope that has flipped across the meridian and recentered all on its own (though hopefully you parked in a bird-safe position at the end of your sequence). The framing and mosaic wizard is pretty slick too (and it relates to plate-solving because SGP will use plate-solving to center you on the area you selected in the F&M wizard before starting the sequence, automagically. SGP is a little more daunting, but now that I've gotten the hang of it I won't be going back.
  9. To echo @spillage , a pretty basic laptop will serve you just fine for capturing at night. I used an old Toshiba with a wobbly clamshell hinge and 4 GB memory for quite a while, running PhD2, Nebulosity, and SGP on it, and it easily managed. Even did a fair amount of processing in PixInsight with it: other than the incessant fan noise, it was able to grind its way along. Earlier in the year the case had finally deteriorated to the point that I didn't entirely trust it, so I upgraded to a Lenovo with 8 GB memory and a small solid-state drive. Again, it has way more than enough power to handle capturing and controlling the rig.
  10. I run off household current: imaging from my back yard. One extension cord from our basement, with a GFCI so I don't accidentally electrocute myself. Much. I have a 12v DC adapter between mains and the Pegasus hub. You could run it off a battery. Without dew heaters on, but with focuser, camera, guide camera and filter wheel I use 7-8 amp-hours over 8 hours or so. Dew heaters add more but I regrettably don't recall how much. In any event, it can run off an appropriate battery w/o an adapter, or off of mains with one.
  11. I have a Pegasus Ultimate as well, though my set-up isn't as advanced as @hughgilhespie has. I have on USB cable from my laptop to the hub, a second to the mount, and otherwise everything runs off the hub including dew heaters, camera, autoguider, filter wheel and focuser. I like the design philosophy of keeping the power hub and computing equipment (laptop, stick PC or what have you) separate, so you can easily upgrade the latter without having to replace the hub itself. The Pegasus hub was smaller and sturdier than I expected and overall I've been pretty happy with its performance.
  12. This is maybe more inspirational than hard data, but it will still make you stop and think: https://skyglowproject.com/ The two photographers who've driven the project have given talks across the US ... not sure if they've done any talks elsewhere.
  13. Well, who's to say that the other image you found is "correct"? ? After all, none of us have ever seen Andromeda that close with our own eyes. That said, play with saturation. For RGB, I saturate after combining the (linear) channels, and before stretching or adding luminance. Stretching reduces saturation. so increasing saturation beforehand results in better color afterwards. Also, after combining and stretching, use an inverted range mask (so you strongly protect the high signal areas) and desaturate the background. Apply a little smoothing and fuzzing to the range mask so that the transition from desaturated to signal areas is natural. That will blacken your background and help the colors pop a little more. Overall, I'd say for your first pass at PixInsight, that's a good effort. Stick with it. I've been using it for two years now and continue to learn with every new project, and the results have gotten better as well (at least in my opinion!).
  14. Well ... everyone is different. I don't spend a lot of time looking at the planets but I do enjoy seeing Jupiter and its dancing moons, and Saturn's rings are still thrilling. I saw Neptune once, and saw Venus as a crescent: pretty cool stuff. I totally get that gray fuzzies are not interesting to many people, but when you stop to consider what you're looking at they get a lot more rewarding. I mean, how many people ever thought that they could stand in their back yard and see a nebula -- A NEBULA -- with their own eyes? Or a ball of stars almost as old as the universe itself (globular clusters)? Or another galaxy? For real. Or the remains of a supernova (the Veil) or the birthplace of new stars (Orion Nebula)? For me, making that personal connection between what colorful photos show and what I can see with my own eyes is very rewarding. And I observe a mile outside the center of a major US city. Under dark skies, you still won't see much color but you'll see more structure. If it were me and it wasn't a hardship, I'd get an 8" Dob and give it a try. The worst that will happen is that you'll need to find someone to buy it from you. The best ... ?
  15. You want to have your focus close before you switch over to autofocus. The autofocus routines generally assume that is the starting point and then test the focus across a range of positions around that point to fine tune it. While focus position can vary somewhat with temperature, I find it works well enough to spend a night or two getting your initial focus (with a Bhatinov mask, or manually adjusting the focuser and using a frame-and-focus utility), autofocusing the luminance or clear filter, recording that position and then using that as your starting position for autofocusing going forward. It will be close enough that 1-3 runs of the autofocus utility will reliably dial you in on subsequent nights and with your other filters.
  16. In general, no: observers don't refer to "gray fuzzies" without reason. ? A middle ground might be "electronically assisted astronomy": using a sensitive camera to progressively stack many shorter color exposures in real-time on a screen. Doesn't take long to get a more detailed image than your eyes can natively perceive, and it's a nice way of sharing some of the excitement with family, neighbors, etc.
  17. Nebulosity isn't free, but between Nebulosity, APT and SGP, Nebulosity is the easiest to get started with in my opinion. It also includes some basic stacking and processing functionality, for turning your hard-earned data into a finished image. That said, if you're getting an electronic filter wheel or you want more sophisticated integration with your mount, then APT is not only less expensive but more full-featured (though without any support for processing). The learning curve will be steeper (though the documentation is pretty good) but it'll take you further. SGP is still more powerful: if you find yourself wanting to full automate a whole night's run, it's probably the tool of choice. But, again, there is a learning curve. I used Nebulosity for about 2 1/2 years and only recently stepped up to SGP, when I decided I wanted to get more sleep (and automate a whole night at a time). With that experience, SGP has been manageable but I'm not sure if I would have wanted to start with it. But, if you're a quick learner, you might do alright with it.
  18. For images (not calibration frames), I organize by target (e.g. M42, NGC5676, etc.), then capture date. All lights and flats from one night go in one folder. If I image a target over multiple nights, I add a "+" to the end of the first date directory. E.g.: M42/2017-12-04+/... M42/2017-12-05/... When I'm ready to process, in the first date folder I make a "processing" sub-folder, and all of my intermediate and fully processed images go there. Bias and dark frames are kept in a separate directory tree, organized by type, duration (for darks) and temperature. Nothing too fancy and I rarely get lost. :-)
  19. Yup. Put the OAG on the light path before the filters (#2). Particularly if you decide to do narrowband, you'll appreciate having unfiltered light to guide from.
  20. I had a very similar experience the other night: star not moving during calibration except for random wiggling due to PE and seeing. By the third attempt I was starting to panic ... and then noticed the ST-4 cable dangling free from the mount. Sigh. It's taken me several nights to get back in the groove after months of weather-induced inactivity. Another night I couldn't get the guide camera to focus ... only to remember 30 minutes later that I hadn't focused the main camera first so the OAG couldn't focus either. Doh. But, each mistake reinforces the lesson learned, and the last couple nights went smoothly. It's frustrating to waste a good night but keep trying: it'll come back together quickly.
  21. Light Vortex is great for learning the ropes. Once you start getting comfortable with the basic processes, then Inside PixInsight will be good for filling in the gaps. That's a great first effort! You have some good star color. Not sure what you did for saturation. I do saturation on RGB before stretching and adding luminance, and also use a luminance mask so the background noise doesn't get saturated as well. Keep working at it: if that's your first effort, you're off to a great start.
  22. Probably in small car territory over the past three years, but I think (hope?) it's peaked. It's a terrible progression though. Upgrade the camera (ouch!) because you want more sensitivity, get LRGB filters because you want color (and now you need a filter wheel and spacers), get a shorty refractor (ouch!) because the repurposed visual OTA is getting too heavy, get narrowband filters (ouch!) because big emission nebula sing in shorty refractors, change up to a long focal length SCT because little targets are too little in the shorty frac, upgrade to a high-end mount (O.U.C.H.) to guide the SCT. And then all the other cruft to go along with it. What is the economic value of round stars, exactly? I try not to think about it much, partly because it makes me wonder if I've lost my mind, but more because the real value comes from using it, and using it as well as I possibly can. It is fun to show off now and then, but if I wasn't using it and pushing to use it better with time, I'd feel much guiltier about the expense than I actually do. I do wonder though: what is the economic value of round stars?
  23. I've never been very interested in terrestrial photography, unlike my father and brother who both had/have life-time interest. AP, though, immediately floated my boat. In part it was the immediate realization that even from our little light-polluted backyard, if I put in the time (and eventually the $ ... sigh) then I could "see" things that I simply wouldn't have thought I'd ever see first-hand, in amazing detail and beauty. And while AP isn't visual, it's also true that the photons that tickle the electrons that eventually develop in a photo are drizzling down right on you and your 'scope right beside you. You are there, even if you don't immediately sense what "there" is. I also like that it's a very "bare metal" hobby. It is not quite so buried in technology and widgets that you lose complete touch with the underlying physics. Polar alignment, guiding, focus and focal length, signal, noise, filters, even the mathematics of processing are all right there in front of you: easy to comprehend even if complex to fully understand. But you aren't isolated from it but advanced electronics and built-in camera magic: you learn the craft with the basic physical elements right there in your hands. All that's not to say that I don't like visual: I do. If I'm getting stressed out about AP -- guiding problems, electronic hiccups, stray moonlight, etc. -- then I do like to get back to basics and do some observing: enjoy things directly without getting overly distracted by the details of AP. But overall I find AP more challenging and more rewarding, and it satisfies my need to work things out from (almost) first principles. Horses for courses, though. There's no best way to enjoy the hobby other than what's best for you.
  24. I have a Flat-Man, made by the same outfit but not permanently attached to the scope. I've been happy with it: can knock out a set of flats in a few minutes, and they make a big difference in the end results. They are pricey, which then opens the question of what is the actual economic value of dust donuts (or lack thereof)? Each must decide for him or her self. ;-)
  25. I started assembling this rig (Celestron Edge HD 8" on an AP Mach1 mount) in early winter, but the weather has been so uniformly awful here that it wasn't until last week that I was able to walk through the polar alignment process and pull a few lights. If we get a break in the weather, it'll be worth the wait: little distant galaxies look like big boys, and guiding error is consistently below 0.5" RMS (against a pixel scale of 0.66"/pixel). I have found the finder to be very finicky, and the thread for the optical or imaging train does not engage easily. Once things are together though it looks very promising. The mount, also, has already shown it deserves its reputation.
  • Create New...

Important Information

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