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QuarkMartial posted:I want to do some basic astronomy, mainly looking at the Moon and getting a closer look at the planets. My students are really interested, too, so having a telescope that can travel okay enough might be helpful (though not necessary). Amazon recommends this one: It’s hard to get something that isn’t painfully bad or just a department store toy for down at $100. First of all, I hope whatever you get doesn’t discourage you from further pursuing astronomy. For $100 (new), you’ll get the cheapest mirror or lens that can be made bundled with some painfully bad eyepieces, darkarchon’s suggestion is about as good as it gets down there, unless you go used. I have spent several thousands of dollars on gear at this point, but if I were to start over and wanted the best planetary views I could get with $100, I would troll Craigslist for a deal on an old Japanese 3” refractor and then get a #11 yellow filter and an X-Cel LX (an eyepiece that doesn’t suck, and doesn’t break the bank) at a focal length that’ll put me at about 150x. That would be easy on the optics and largely doable on the skies in most parts of the country. Going cheap-as-can-be-but-not-painfully-bad I would spend $150 on a used 6” Orion XT6 (or equivalent) and probably something like an X-Cel LX at a focal length that’d get me to 200x. A cheap wide field eyepiece too for sweeping the Pleiades and such. edit: it occurs to me, I keep mentioning the X-Cel LX series because it has decent eye relief for glasses wearers. I have enough astigmatism that I need to wear my glasses at all magnifications and exit pupils, so having the space to wear them comfortably between my eyes and the eyepiece glass is a good thing. If you DON’T have ruthless astigmatism like me, you can focus out your myopia with the telescope and eye relief isn’t as much of a problem. Still, you want to budget in an upgrade from the lovely poo poo plossls that ship with cheap telescopes. edit2: oh, if you’re a planet observer, you have time to save money. Jupiter doesn’t reach opposition until May so your best observations won’t happen until a couple months from now at the earliest. duodenum fucked around with this message at 04:11 on Nov 16, 2017 |
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Nov 16, 2017 03:52
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There are about as many astronomy gear opinions as there are amateur astronomers! One thing I learned quickly at the beginning was that trying to show my son anything resulted in watching him work on getting his head and eye placed properly on the eyepiece while the object slid through and out of the field of view. When you're viewing Jupiter at 200x or more, you'll definitely see it march on by. So you'll experience pushing the scope, finding Jupiter, and saying quick climb these steps and - DON'T TOUCH - oh crap - now get down - let me find it again. Ok now climb up again and look - try - try - hmmm - uh, ok now Jupiter is gone. Climb down and let me push the scope again. Tracking is definitely valuable when you intend to show kids an object. A whole line of kids like your middle school class? You definitely want tracking. https://agenaastro.com/sky-watcher-virtuoso-mount-90mm-mak-cass-telescope-s11750.html Thats a simple table top tracking mount with a small maksutov cassegrain. Great for planets and the moon. You will want to put it on a very stable table and have a nice observing chair. On uneven ground, three legs are more stable than four. Just make sure it's as level as can be for decent tracking. https://www.amazon.com/Celestron-NexStar-90SLT-Computerized-Telescope/dp/B0038LX8WU/ This one has its own (barely sufficient) tripod, but the mount is capable of locating and tracking objects, instead of just tracking. A lot of marketing materials tout computerized telescopes having a database of several tens of thousands of objects, but at 90mm of aperture, you won't be able to appreciate any of them except for the absolute brightest. So, it'd be for planets, the moon, the pleiades, the orion nebula, just bright things. Bright things that you can locate yourself with a minimum of knowledge (iOS app) and a little patience. So, the "go-to" is almost superfluous, but the tracking is not. The simplicity of the Sky Watcher Virtuoso set up in the first link appeals to me more, especially because it leaves room in the budget for an eyepiece that doesn't suck. Which you *will* need. The 90mm Mak in either set up has a focal length of 1250mm. Divide that by the eyepiece's focal length for the magnification factor. https://agenaastro.com/celestron-7mm-x-cel-lx-eyepiece-93422.html 1250/7 = 178x, which is about what this scope should top out at, realistically. 178x isn't too ridiculous for most peoples' skies, either. Warning: skimping on an eyepiece will make sure your whole telescope experience sucks. Getting a "kit" of plossls from Celestron or Meade is just getting a kit of minimally useful and poorly made pieces of crap. A quality eyepiece makes a HUGE difference. The X-Cel LX series or Meade HD-60 series is about as cheap as I'd go.
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Nov 21, 2017 19:02
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Looks nice! Did you use the newtonian on this one?
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Nov 25, 2017 14:31
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Right, I was seeing spikes in these stars and assuming spider vanes. Apparently refractors can artifact like that because of spacer clips or collimation screws or pinched optics or something. Googling Pleiades photos shows HUGE diffraction spikes where obviously a newt was used, definitely more pronounced than yours. Nice photo though, not trying to be overly critical. I have really *no* experience with astrophotography.
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Nov 25, 2017 18:08
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Nude Hoxha Cameo posted:How do you find that scope / mount, apart from AP? I was thinking of upgrading from an Orion XT6 to that one. I've had both the Orion XT6 and the Celestron 8SE. I was fortunate that both examples I had were great performers. Both are pretty much one-trip carries out to the back yard, awkward, but doable. Both put up *really* great images of planets and the moon from my light polluted back yard. The XT6 is easier to collimate than the 8SE, but neither required collimation very often. The 8SE would be easier to attach a camera or binoviewer to, as there'd be plenty of back focus. The XT6 does not have a problem with dew, but the 8SE definitely does (your climate may vary) and requires a dew shield at least, heated dew shield probably recommended. The 8SE has a more consistent focuser/eyepiece position than the XT6, more easy to use seated for long periods of time. The XT6 has no barrier to being used immediately. You plop it down and in a few minutes your little mirror is acclimated and you're off and observing. The 8SE requires a bit more acclimation time, as its heavy primary mirror is fully enclosed and doesn't cool down as fast. I usually would put it out in the yard before dinner and an hour later it'd be ready to rock. The 8SE isn't easy to use without powering it up and aligning it, but that tracking is also a big strength. I found it very difficult to share the view with my kids with the XT6. You find Jupiter at 200x and get your kid up on the step to get to the eyepiece, and by the time they can see through it, the object has drifted out of sight. The 8SE will locate and track objects, and that makes for a much more relaxing experience sitting there studying the planet or whatever. Nicer than trying to glide on the XT6's cheap bearing system, and easier to share the view with friends and family. If you save a bit more, the Nexstar Evolution is a worthy upgrade from the SE. Built in wifi and battery, much stronger arm. The 8" SCT on the SE mount maxes it out and the thing will quiver for a few seconds every time you touch the focuser, the Evolution is much more stable. Both the XT6 and 8SE are great, I'd have an 8SE if I could have only one. It's several hundred dollars more, so it's not really a fair fight. duodenum fucked around with this message at 03:16 on May 18, 2019 |
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May 18, 2019 02:47
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Rime posted:Yo thread, I wanna buy a big-rear end telescope 'cause my Meade 50x from 1996 just doesn't cut it anymore. What's the biggest I can get and still cram it into a vehicle / bicycle cargo trailer, but which will make DOS's look really awesome to the eye? I have little interest in astrophotography, I just want to oogle pretty globular clusters and such. Big aperture bouncing around in a bike trailer is probably bad news. If you like globs, maybe a 120ST, Hyperion Zoom, a Twilight I, and some dark skies, that'd hold up to bouncing around a bit. Unless you like assembling a truss and collimating.
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May 18, 2019 03:14
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Nude Hoxha Cameo posted:Thanks *so* much for this, it’s exactly the sort of information I was looking for! I’ve enjoyed using the XT6 but we always go out as a family, so sharing views is key and quicker finding will also be helpful. And I’ll definitely check out the Evolution as well. The diagonal that ships with the 8SE or the Nexstar Evolution is pretty cheap and should be your first upgrade. You can stick to something like this until you become a seriously seasoned observer... then you'll probably be spending two to three times that for a Zeiss prism or whatever your preference becomes. The eyepieces that ship with any new scope are almost always pretty bad, especially the high power (small focal length number) ones. This series of eyepieces is pretty great bang for the buck. You might also consider the Baader Hyperion Zoom ($290 new, you can find them ~$200 used). It tops out at 8mm (~250x in an 8" SCT), which is more than enough for your average seeing w/r/t high magnification planetary observing. The Celestron Zoom ($65) is not bad, but not *nearly* in the same class as the Baader for viewing comfort and wide apparent field.
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May 18, 2019 20:01
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slidebite posted:a few year old HEQ5 on sale. Asking $400 The hand control is the type you'd use for simple dual axis drives, so this wouldn't be a goto mount. It would track something once you found it, but it won't be locating and slewing to objects on its own. The counterweight bar isn't visible, but on this mount it's supposed to stow up inside the mount. Might check for that. There also aren't any counterweights apparent in the photo, so check for those, too. Counterweights are more expensive than you'd realize. As a mount, it's an excellent match for a C8, but it wouldn't automatically find objects like an AVX. The AVX is a pretty good value at its price point, and it has a very wide install base if you have problems or questions.
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May 22, 2019 19:34
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Here is the actual mount
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slidebite posted:Sorry if this is a dumb question, but is buying a wedge like this Wedges can be effective, but your 8SE is a long focal length OTA on a mount that's barely able to accommodate it, even for visual use. The 8SE is wholly unsuitable for long exposure photography, the wedge will tax the SE mount even more and your results will be very frustrating. If you want to use the 8" SCT as an astrophotography platform, you might consider Hyperstar. It's an attachment of optics that replaces the secondary mirror. You can attach a camera then to the front of your scope and collect light really REALLY fast at f/2. Combine that with a modern CMOS astronomy camera like an ASI294MC and you can get some great results with super short exposures live-stacked and no need for an equatorial mount or a wedge. With Hyperstar and an ASI294MC, you can do decent DSO photography with an 8SE. Hyperstar and an ASI294MC will cost you about $2k Another thing you can do is maybe get that wedge and a small refractor. You can probably get some exposures with your SE mount on a wedge using a small refractor. If you want to do AP, get a refractor and a field flattener. That's probably the most forgiving way to get started.
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May 27, 2019 03:56
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Golden-i posted:I'm actually thinking about getting a refractor for DSO AP use. Any suggestions on something that I can mount on my AVX? I'm hoping for something a little lighter than my existing 8" reflector, which I love a whole lot but I think is just a little too heavy for accurate tracking at this point. I just don't know anything about refractor scopes at all, I've never actually used one. If you intend to upgrade your mount and OTA later, and just want to get some reps in right now for the practice of it, get a decent ED doublet and a field flattener. When you get your real mount, you'll have some experience and you'll have more of an idea of what you'd really want. 60mm ED FPL-53 Doublet https://www.astronomics.com/astro-tech-at60ed-60mm-f-6-fpl-53-ed-doublet.html Field Flattener https://www.astronomics.com/astro-tech-at60ed-field-flattener.html 72mm ED FPL-53 Doublet https://www.astronomics.com/astro-tech-at72edii-refractor-ota-fpl-53-f-6.html Field Flattener https://www.astronomics.com/astro-tech-0-8x-reducer-field-flattener-for-f-6-refractors.html 80mm ED FPL-53 Doublet https://www.telescope.com/Orion/Tel.../332/p/9895.uts Field Flattener https://www.telescope.com/Orion-085x-Focal-Reducer-Corrector-for-ED80-f75-Refractor/p/5195.uts Any of these wouldn't tax the AVX at all, they'd be forgiving, relatively cheap, and they'd be useful as guide scopes if you upgraded to something epic later on.
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May 31, 2019 22:49
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Golden-i posted:Thanks! The last two times I've been out, I've very carefully balanced both axes as best as I could. Last night I made sure to balance it after I mounted the camera, tracking camera, and cabling, just to be sure. I think I'll see what happens with a lighter scope on it to really see if it's a weight issue or if maybe I'm just doing something wrong. The focuser on the Sky Watcher is a good upgrade, but it still not really a premium focuser. It also comes with a diagonal, a couple of cheap eyepieces, rings, and a dovetail and an aluminum case. The Orion is a bare bones OTA, but the glass is the same. Both scopes have a good optical reputation. I love your pinwheel shot, nice work! edit: the fit and finish on the AT72EDII that you mentioned considering is going to be noticeably better than than either of the Synta 80mm scopes. The focuser will be noticeably better than either, a proper piece for hanging heavy camera gear. duodenum fucked around with this message at 03:33 on Jun 3, 2019 |
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Jun 3, 2019 03:30
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Internet Explorer posted:This is super useful info, thank you. With an Alt Az mount you'll see field rotation in long exposures (Say, at or above 30 seconds). Fortunately, with today's super low noise CMOS cameras, you don't have to have super long exposures to get good frames that you can live stack with SharpCap (or similar). People use Alt Az mounts to view DSOs with live stacking from their back yards pretty effectively. Now, if you want to do longer exposures and get into really fine professional astrophotography, then you'd want an equatorial mount.
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Jul 25, 2019 20:47
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Luceo posted:I'm considering upgrading to 2" eyepieces on my 8" dobs. Any recommendations for a decently-priced basic set? You only need 2" barrels when your field stop is bigger than a certain diameter. 2" barrels all the way down to your smallest focal lengths is a waste. You only benefit from the additional diameter at low magnifications. When you're eyepiece shopping, there are many things to consider. I assume your 8" dob is an f/6? (1200mm focal length) The reason I ask is because fast focal ratios can be tough on cheap eyepieces. f/6 is friendly enough for most anything. Second thing to consider is whether you have astigmatism. Regular myopia can be focused out, but if you have astigmatism, you'll want to wear your glasses at low magnifications. If you need to wear glasses at low magnifications, then you'll want to choose eyepieces with good eye relief. How much money are you thinking of spending? (removed bad paragraph because of bad math) If you live in the burbs or under light pollution, your dark adapted eye probably won't dilate wider than ~4mm, so going below about 25mm will only be useful if you drive out to dark skies. The Explore Scientific 68 degree 24mm (50x) and 28mm (42x) eyepieces would be good bang-for-the-buck medium-low magnification eyepieces with reasonable eye relief. You'll notice that going from 24 to 28mm at 68 degrees FOV, the field stop requires the jump to a 2" barrel. Here's the 24mm in a 1200mm focal length scope: The Double Cluster will look awesome and well framed like this, in the winter time.  The Hercules Cluster is up now, and well framed by the 24mm at 50x:  Unless you're out at a dark sky site, I wouldn't go lower than 24mm. god drat that was a rambling post and I'm not sure I even answered the question. Don't buy a kit of plossls. duodenum fucked around with this message at 22:15 on Jul 25, 2019 |
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Jul 25, 2019 22:03
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Dick Trauma posted:This might sound like a strange question but when you are setting up these photos what do you actually see? Here's an example of EAA, Electronically Assisted Astronomy. This guy uses a C8 on an Alt Az mount with Hyperstar, which means he's imaging at f/2 and he's using a very sensitive low noise CMOS camera in the ASI224MC. Occasionally you'll see him slew the telescope and you see the streaks of stars, and when he settles on an object, you see the nebulosity immediately. he then sits on the object there and collects/stacks a few more frames. The additional data smooths out the noise and you begin to see more detail. The app he's using allows you to tweak the histogram, setting the black/mid/and white points, so you can view the data as you please as it comes in. https://www.youtube.com/watch?v=iTgVT_WGThM Actually in this video, he's not stacking. Just viewing the 1 second frames as they come in.
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Jul 25, 2019 22:25
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Luceo posted:Thanks for all of this! It's an f/6, yes, and I don't have astigmatism. My area has lots of ambient light, but it's alright for a suburb. I'm looking at a few hundred bucks. I'd get 3 eyepieces, maybe 4. With no need for glasses and a "few hundred bucks" to spend, I think I'd still recommend the ES 68 and/or 82 degree eyepieces. Great bang for the buck. Divide your scope's focal length (1200) by the eyepiece's focal length to get your magnification. Shoot for 200x for planets, with your 8" of aperture. Maybe 250x if you feel like you can smoothly push the dob and keep up with the planet scooting on by out of your FOV. (200x is plenty, unless you have a tracking mount) Another eyepiece at about 100x, and a third at 50x. Sit on those for a while and see what you like, what objects you enjoy and where you'd think you'd add an additional focal length. So, something around 6mm, 12mm, and 24mm. Maybe an ES82 11mm, a Barlow to make that 5.5mm for planets, and the ES68 24mm or the ES82 24mm, depending on your budget.
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Jul 25, 2019 22:36
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Platystemon posted:The exception being eyepieces with wide apparent field of view. That's true! I wouldn't want to hang an Ethos off a 1.25" barrel.
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Jul 25, 2019 22:59
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Golden-i posted:this is a rough approximation of what I was able to see of the Dumbbell Nebula (roughly the same magnitude as the Pinwheel Galaxy) with just a low-magnification eyepiece: The Ring Nebula as a ghostly gray and faint ring with my 6" of aperture and Bortle 8 skies. Did you see color in the dumbbell visually? I get the impression that seeing color in DSOs (outside of M42) is the stuff of huge aperture dobs and ladders in the darkest of dark skies. ...and maybe young eyes. I'd like to get more experience with dark skies, for sure. I'm jealous of that Bortle 2 Cabin!
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Jul 25, 2019 23:19
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Internet Explorer posted:Ugh, this is what happens to me every time. I've done hours and hours of research and then I get gear decision overload. I'm wondering if it doesn't make sense to just get the Edge HD 8 with the AVX Advanced and then just upgrade the mount when the time comes. The EdgeHD 8" on the AVX is $2,149.00. That combo would be fine for visual, but the 8" SCT on an EQ5 class mount is not going to make you very happy if you want to do real, long exposure astrophotography. If you got just the AVX, you'd have like $1200 left for an OTA. If you're rolling in cash, $1200 is within spitting distance of the $1650 Esprit 80mm triplet (includes field flattener), which would be a fantastic OTA for photography maybe for a lifetime, depending on your preferences. But go easier on your wallet and your AVX and get an AT60ED or AT72EDII with a matched field flattener. Then you'd be on your way.
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Jul 26, 2019 00:15
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Here's another taste of EAA. Just a guy with his camera hooked up to a telescope, browsing around at about 4FPS or so. https://www.youtube.com/watch?v=z80vnWCLc3o After the first slew between the Lagoon and the Trifid, he seems to have edited out the slews (another one at 3:25). I like the slews, the context makes it feel more real and fun. EAA, or video astronomy, is pretty casual compared to serious Astrophotography like some of the pretty stuff you've seen people post in this thread. These short exposures don't require a really nice equatorial mount. You can get into this kind of thing with something like the Sky Watcher AZGTi (control your scope via wifi with your phone or tablet), a small refractor (ideally, for simplicity), and a nice sensitive, low noise CMOS camera like a ZWO ASI294MC (non-Pro, unless you intend to do LONG exposures). Optionally, a field flattener and a light pollution filter. The guy in the video doesn't even bother to comment on the amp glow coming from the left corners, because that's not the point. Select an object on your phone, slew to it, view it on the screen. Maybe try a longer exposure, maybe try higher gain. Hey that's pretty cool, what's next? Select it, slew to it. ZWO also makes a Raspberry PI based thing called ASIAIR which connects to your mount, your camera, and an Android or iOS tablet. Stellarmate is another one, a bit more complex (and capable). Putting this kind of thing on your tablet without much of a hassle. Well, I guess the hassle is relative.
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Jul 27, 2019 21:25
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Here's another way to do live astronomy, with a several thousand dollar Gen 3 night vision tube, viewing the sky at about 4x. Just like you're looking up with night vision eyes. https://www.youtube.com/watch?v=--xZmXnFOM8 Same guy, using a White Phosphor tube. Big bucks. https://www.youtube.com/watch?v=Dq706Oa_X0g Same guy again, this time through a scope with some magnification. He slews from Lagoon to Trifid (like the guy in the last post) at about 1:18 https://www.youtube.com/watch?v=UxBdtqExxvs I prefer the look using a color CMOS camera, but the night vision thing is pretty cool.
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Jul 27, 2019 21:41
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Satellites. Very common. https://en.wikipedia.org/wiki/Satellite_flare
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Jul 29, 2019 02:55
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Hasselblad posted:Satellites do not change course several times over the span of a couple minutes (at least not enough to be noticeable to the naked eye) I wasn’t talking about your spooky x-files stuff.
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Jul 29, 2019 05:04
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Internet Explorer posted:Alright, I think I'm going to go a bit over budget, which is completely fine, and get a Explore Scientific Carbon Fiber ED102 f/7 APO Triplet and a Celestron Advanced VX. The Asteotech stuff looks really great, and ideally I'd buy something of theirs, but the good stuff is out of stock and I'm in a bit of a time crunch. I can afford the extra spend, and the carbon fiber thingy is on sale for $300 off so it doesn't seem as stupid of a purchase. Are you talking about this one? https://explorescientificusa.com/collections/telescopes/products/ed102-fcd100-air-spaced-triplet-telescope-carbon-fiber That is some serious business!
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Jul 30, 2019 13:50
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hannibal posted:There was a transit of the ISS across the Sun visible from my location today. I was able to record it, full details here: https://www.instagram.com/p/B0sMnqWF-qy/ Awesome stuff, nice job!
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Aug 3, 2019 16:32
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Golden-i posted:The East Veil Nebula Thats beautiful. Is that from a dark site and/or did you use any LP filters? Great info. Thanks for the great effortpost. Sometimes I see vanguard posters on forums there and there who disagree with conventional wisdom and say that the low noise and sensitivity of recent modern CMOS cameras changes the exposure conventional wisdom coming from the older corners of the internet. Sensors like Golden's ASI294MC are capable of a lot of dynamic range without long exposure times. I don't usually get too deep into it, as my interest is more in visual for solar system objects and live viewing via live stacking for DSOs, not optimizing for super sexy real astrophotography. Robin (SharpCap guy) does into a lot of details about sky brightness, noise, exposure length and such here, it's a great few posts that goes along with hannibal's post.
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Aug 4, 2019 23:09
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hannibal inspired me so I put my tattered, old, but still awesome Orion 80ED on my old-rear end Nexstar GT, and set it outside with a Baader film filter over the top and pointed it at the Sun. I got it to focus with an ASI224MC with a couple of extension tubes, but the Houston sun was murdering me and my poor MBP so I fled into the glorious AC. Still, I was ready for what would have been a good ISS transit of the sun. But, god drat Houston, the clouds rolled in and I couldn't get it. Being outside in the day time is over rated.
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Aug 6, 2019 03:03
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Golden-i posted:Well, poo poo, I can read french so that might be nice if it could save me the money! Can you point me in a direction on that? Heres a good chat on spacing for the GSO coma corrector, if you decide to go that way. https://www.cloudynights.com/topic/462985-setting-up-the-gso-coma-corrector/
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Aug 8, 2019 03:20
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GSO coma corrector with spacer popped up used! https://www.cloudynights.com/classifieds/item/179650-gso-coma-corrector-wspacer/
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Aug 8, 2019 19:35
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Nerobro posted:So... i'm interested in building a PiKon. (that is a home made telescope using the Raspberry Pi camera, and some janky gear to have a single mirror telescope) https://makezine.com/projects/gaze-across-the-solar-system-with-a-3d-printed-raspberry-pi-telescope/ That looks like a lot of effort and a lot of hype for something that doesn't work very well, and isn't even complete. Their own demo image has that weird purple color cast and vague focus, I can't imagine it getting much better than that. [I'm going to just delete a whole bunch of details because it sounds like I'm just piling on and getting mean.] If you want to "make" something that might please you when you're finished, check this out: http://www.openspaceagency.com/ultrascope
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Aug 13, 2019 03:45
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I definitely don't want to come across as insulting, nothing personal. Lots of effort for something that won't work very well. I'll just throw out my thoughts and maybe some of the more knowledgable/experienced guys can corroborate or disagree. If the RPi's camera is two generations better than the one they used to take their demo pictures then maybe something can be made interesting. The plans are for a mirror cell and a spider. You provide the mirror, and I assume the way to a mirror is to find a garage sale or craigslist scope. They specify a spherical mirror, which means that the mirror will have a long focal length (to minimize the aberrations due to it not being an actual parabola). You're going to put a long (long) tube on an equatorial mount for AP purposes? That mount will have to be a $1500 EQ-6 class or better, and the tube will have to be sturdy to prevent flexure. They spec a PVC pipe. Here's a 4.5" spherical mirror in a metal tube with a secondary mirror, so it would be a little shorter than your PVC OTA. The mount in the picture is a joke, even for visual use. Let alone holding that thing steady enough for taking pictures. https://www.bhphotovideo.com/c/product/285218-REG/Celestron_21045_PowerSeeker_114_EQ_4_5_114mm.html If you get a 4.5" parabolic mirror with a shorter focal length, you can make a shorter tube, requiring less mount. Parks has a 4.5" f/5 for $300 http://www.parksoptical.com/product...+Primary+Mirror You might find a 130mm f/5 newt out in craigslist land, that's relatively common (Celestron, Meade, Sky Watcher, Vixen, Orion all have made 130mm f/5 news for a while), but you'd need a different mirror cell, tube, and spider. The spider they show has three thick vanes. Three vane spiders produce 6 diffraction spikes, but the spider vanes on this thing are very thick and don't extend radially out from a central point. It makes me think you'll have a spike on either side of a star for each one of these vanes, and they won't cross at a central point. There is some app to model diffraction, but I don't know what it is. Seems like it'd be a very weird look. Seems nonsensical to scrap a mirror cell and a spider from a craigslist dumpster-newt so you can 3D print a new and inferior mirror cell and spider. You can just extend the old newt by a few inches and use the hardware you have to make something lighter and probably more collimatable. Some newts are long enough that you might just have to drill holes to move the spider up and the mirror cell down to get the prime focus where you need it.
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Aug 13, 2019 23:43
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Internet Explorer posted:Is anyone jumping on the Stellarvue SV102-Access deal? Seems like quite the buy. Normally $1,095.00, on sale for $695.00 as a close out. I would love to jump on that deal but I've spent way too much money on telescope crap in the past couple years. :\
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Aug 15, 2019 03:23
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hannibal posted:Did another ISS solar transit today. That's awesome. I got clouded out on the nearby transit that I tried, but I haven't checked the transit website since then. I need to keep trying!
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Aug 25, 2019 18:56
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That mount is so awesome, the load bearing surfaces of your RA and Dec axes are almost a large as your OTA's primary mirror!
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Sep 4, 2019 13:48
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polyfractal posted:And in other news... I realized my coma corrector doesn't actually work for my f/3.9 newtonian Sky Watcher makes a whole line of f/4 imaging newts and this is their coma corrector for f/4 https://www.bhphotovideo.com/c/prod...2UaAsw0EALw_wcB I have no experience with it, but it might be an option. B&H has a pretty good return policy if you can get out and test it soon after you get it.
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Sep 14, 2019 22:48
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I have the Baader MPCC which the manufacturer claims goes down to f/3.5, but I'm still seeing pretty bad coma. Looked around and it's apparently pretty well known that it's only good to about f/5 and makes coma worse any faster than that. Welp.
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That is totally awesome, nice job!
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Sep 18, 2019 14:12
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Golden-i posted:80mm SkyWatcher refractor... Esprit 80mm or Pro ED (Evostar) 80mm?
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Sep 24, 2019 00:25
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Golden-i posted:The espirit 80mm APO, it looked better for photography if I remember correctly. I am a jealous mother fucker. Lifetime scope, there.
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Sep 24, 2019 00:33
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The 130P is going to be a really convenient little light weight scope, its primary drawback will be the need for collimation. Roughly collimated and with a decent wide field eyepiece, it'll be a pretty fun sky sweeper. For high magnification viewing, you'll want to collimate as precisely as possible. Anything over 150x will probably benefit quite a bit from attention to collimation at f/5. You probably don't want a huge turkey leg eyepiece, the little focuser and tabletop mount might not be happy with that much weight on the front of the scope. You seem to have some eyepieces to experiment with, we don't have to go down that rabbit hole unless you're interested. The AR127L is a huge 5" achromatic refractor. The EQ5 is good enough to carry it, but barely. By that I mean that moving the scope or touching the scope to focus it will cause it to shimmy for a few seconds, you have to wait for it to settle to see if your focus attempt was successful, and then try again. If you get a clock drive, or even a go-to kit for that EQ5, you could point the AR127L at something, focus, and then not touch it. That would be ideal. It will, in all likelihood, put up GREAT images of Jupiter and globular clusters and such. (Omega Centauri and 47 Tucanae will probably make you poo poo your pants through the AR127L). It being an achromat, it will probably display a purple halo around bright objects like Jupiter, the brightest stars, and the limb of the moon against the black sky, but forgive it for that, because it will probably put up really good images and be very pleasant to look through. The downside is its size. Pointing at anything high in the sky is going to have you sitting on the ground, even with your tripod legs all the way out. Legs all the way out make your mount even more wiggly than it would be otherwise. Long refractors are tough to mount, but if you can live with their drawbacks, you'll be happy with the views.
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Nov 6, 2019 21:29
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I like the natural look of the second image. It makes me feel that that's what it would look like if I had eyes sensitive enough to just look up at twilight and squint my eyes a little bit to focus on the Ha. You just got your Esprit 100mm, we need some sexy gear pictures!
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Nov 11, 2019 19:36
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Golden-i posted:And the product of last night, the Pleiades Great scope, great mount, photo has nice round stars out to the corners. I always like finding UGC 2838 in nice shots of the sisters. Now I am *not* a seasoned Astrophotographer, so I have no authority from which to criticize, but what is your post-processing method? It looks like you've stretched in a lot of visible noise to bring out nebulosity, and the non-Pleiades look a touch red-ish. I've seen some say that they try to white balance their images by aligning their histogram peaks, and this effect is what I fear. There is a lot of blue, naturally, in this image and if you crank up the red histogram peak to "balance" the image, you'd be pushing the red higher than it should be. Is that what's going on?
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Nov 23, 2019 23:21
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