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rickwayne

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About rickwayne

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    Star Forming

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    Madison, Wisconsin, USA
  1. You may find that e.g. Vega is good to get roughed in, but that dimmer stars will allow you to better discern small focusing errors. Use ISO eleventy-million for the shortest exposure times possible, and definitely use magnification of the live view to really peer at the details.
  2. You want to do all your proc in PI, right? If you were using Photoshop you could just layer the original starry image above the nicely-processed nebulous one and set the top layer's blend mode to "Screen".
  3. You can pick up a used Ha filter somewhere and get started right away. You don't have to have a filter wheel, the ZWO cameras let you mount a filter easily. With just Ha you can do things like this, or this, or this.
  4. Welcome! Holy BUCKETS that's a lot of millimeters for starting out! Certainly won't say it can't be done, but DSO is a real course of sprouts to begin with -- you're setting yourself up for some challenges with that mount and that long a scope. But if you're on a budget, the conventional advice ("Just get a short refractor to start with") is, um, unlikely to appeal. I would heartily second the reducer advice; someone with experience with SCTs will have to recommend which one, or if you need a flattener/reducer. The advice about image scale is also spot-on. Really, if the pixel size is appropriate, a DSLR lacks but one advantage over an uncooled astro camera: Better hydrogen-alpha response. So I doubt the increment over your existing camera is likely to be worth the money; my advice would be to shoot with your existing camera until you can save up for a cooled astro cam, which will give you better H-alpha but also lower noise, and allow you to shoot dark frames at your convenience and reuse them, rather than wasting dark-sky time shooting them in situ. I will give you my "conventional advice" for two purchases, though: Charles Bracken's The Deep-Sky Imaging Primer and Astro Pixel Processor.
  5. In principle video stacking can be used for deep sky objects, but since they're so dim, hours of integration time are usually required. But that doesn't mean you can't get results that please you.
  6. Zoom lenses are in general not well suited to astro -- too many compromises in their design, and slower than comparably priced primes. (Yes yes, #notallzooms. In general.) I've seen some great work done with inexpensive old manual-everything prime lenses. While an alt-az mount can track, it will display field rotation in longer exposures. Just the nature of the beast.
  7. Platesolving also enables enhanced polar alignment. I use Ekos, but certainly other s/w exists for it.
  8. There are also several deep sky objects that don't need a ton of magnification. In the winter the Orion Molecular Cloud Complex can be imaged with a 50mm; the North America and Pelican Nebulae are also pretty big (one of Carole's shots is of the NA). The Andromeda Galaxy won't fill the frame by any means at 135mm, but it will certainly dominate the image. The big advantage of compositing short exposures together for star trails is that no single event can ruin your image. E.g. kicking the tripod, vehicle driving by with headlights, firefly landing on the lens...if you have one super-long exposure, any of those can tank it. If you're putting together short ones, you shrug and throw that one away. I use Photoshop and a "Maximum" stacking mode on Smart Objects, for what that's worth. You do have to be careful about the downtime between exposures, if you look carefully at this image the trails look sort of "dotted":
  9. Astro Pixel Processor for: Calibration (darks, flats, bias, bad-pixel map) Stacking Light pollution removal RGB compositing (I shoot narrowband or RGB) Initial stretching Starnet++ for star removal Photoshop for: Localized contrast enhancement Cropping, rotating Final color adjustments Denoise (Topaz DeNoise AI) Sharpening Re-compositing starless and star layer I used Siril until I got APP. No comparison in ease of learning and ease of use; I think I'm getting much better results out of APP with far less fooling around. Light pollution removal all by itself is worth the candle. Note that APP and Starnet++ run on Linux.
  10. Definitely go with the S model. It's been awhile but I'm not at all sure the USB problems were limited to Linux. And you may as well have the faster download available -- who knows, you might be imaging planets one day and want to shoot video. I don't have a basis for comparison since I've only ever had one guide camera, but the MC seems to do fine. I've had a couple nights where I was getting 0.6" RMS on my CEM-25P with it, though habitually I see more like 1.2".
  11. The Orion Molecular Cloud Complex is chock-full of fun stuff that you can make out with quite short lenses. This is hardly APOD, but was done with a 50mm in February: Barnard's Loop, Orion, Horsehead, Flame Nebulae
  12. I would heartily recommend developing and using a checklist if you're going to be out of your customary context. Super-easy to forget something! lonelyspeck.com has a series of articles on Milky Way imaging for the novice, that's how I started. If your camera is ISO-invariant over a range, favor lower ISOs to maximize dynamic range. And of course test when you get there, if the skyfog peak of the histogram doesn't touch the left edge then that's the right exposure. Sounds like a real winner -- enjoy! swagastro.com if you want to see what the imaging possibilities are in Spain. >;-}
  13. This is very common advice, but here goes: While you can pick up individual bits of information from videos or forum threads, IMO the very best way to start is with a good general-purpose book like The Deep-Sky Imaging Primer or Making Every Photon Count. That will give you a solid grounding in the whys and wherefores, the problems that the particular techniques or bits of equipment are intended to solve. TDSIP is how I got my start, and I still refer to it fairly often. You don't have to be a physicist or engineer to understand this stuff well enough to do great images, but basic knowledge really, really helps. For example, planetary imagers often shoot video and use software that assembles the best bits out of hundreds or thousands of frames, while deep-sky guys and gals do multiple long exposures and use all of every frame. These books will explain why.
  14. I thought about starting a new forum "Imaging For Four Years But Still Mostly A Moron At It" but didn't think anyone else would join.
  15. I haven't had a successful imaging session since <checks catalog> January. Sheesh! This bicolor West Veil is with a Stellarvue SV70t-IS, ASI 183MM-Pro, ZWO H-alpha and OIII filters. 20x180" on each. Gotta love narrowband -- lights around this athletic field were so bright I hardly needed a flashlight for anything. Astro Pixel Processor, then Photoshop for a little tweaking, denoising, and sharpening. I may have pulled on the saturation slider a tad Full tech deets at astrobin.
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