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Luna-tic

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Everything posted by Luna-tic

  1. Do you specifically want go-to, or is a manual mount with available tracking enough? My first setup was a C6 and an Orion Astroview EQ mount, it was excellent. It is not go-to, but you can get it with RA tracking which was quite good for its price. The mount is lightweight and easily carried and set up, what I consider definitive for a grab-n-go. It will easily carry the C6, so the C5 would certainly not be a problem. And with an EQ mount, no issues with viewing at zenith. I've also used the setup as a spotting scope at the rifle range, the EQ mount presented no problems for terrestrial use.
  2. My 'perfect pair' is my Edge HD 8" and my WO GT81. I can image at f/ ratios from F4.7 to f/5.9 to f/7 to f/10 and have varying fields of view depending on what I want to see. They are both compact, relatively lightweight, easy to carry, don't require a huge mount; the optics of both are great quality and easily share EP's between them.
  3. The knurled ring turns anticlockwise and you then remove the secondary mirror and holder; as mentioned you can then affix a Fastar/Hyperstar assembly for f/2 AP. There is an index pin on the secondary mirror holder to properly locate the secondary, and then you turn the knurled ring to tighten the holder in the corrector. The three small screws are your collimation screws. DO NOT remove them, or the mirror will fall out of the holder and you'll likely have to remove the corrector to get at the secondary to replace it. The mirror holder has a post in the center, which the secondary mirror "rocks" on, held still by the three collimation screws' tension. When collimating, if you loosen one screw, they will all become slightly loose, and collimation consists of slightly loosening one and tightening another, causing the mirror to pivot slightly on the post behind it. It's a tedious, but uncomplicated procedure. You might consider a set of Bob's Knobs to replace the Phillips screws, it makes collimation a tool-free task. If you do switch them out, be sure to read and follow the instructions carefully.
  4. I have a secondary 7" screen that connects to the HDMI port of my DSLR, and shows whatever is on the camera's rear screen. It has a focus assist feature that puts a red border around whatever is in focus. It also allows me to have the camera pointed at high objects and still see what's on the screen (my Nikon's rear screen is fixed), and see it larger than what the screen shows. So, for faint objects, I first find a bright star that easily shows on the screen, and focus until the star turns red. It's pretty much an infinity focus; then I move to my intended subject and fire away. I use this screen for multiple things; I have a cheap EP camera that fits on the end of an EP, and projects the image to the screen; works great for outreach with people who have difficulty seeing the objects in an EP (kids, old folks, etc.). It's not really much different from using a laptop's screen, except for the focus assist feature, and that it is very compact. It has better resolution than the camera's screen, too. This is the gizmo I'm using: https://www.bhphotovideo.com/c/product/1398766-REG/elvid_7_4k_on_camera_monitor.html
  5. What are the differences between the Starsense for the AVX mount (or other Celestron mounts) and the Starsense sold for the Skywatcher Synscan mounts? For Synscan, it costs about $200USD more, and the ads show a 'junction block' that doesn't come with the one for Celestron mounts. I have the Starsense for my AVX, and am considering adding a Skywatcher EQ6R. Is the software different between the two Starsense versions, or is one compatible with the other? Sure would like to be able to use the one I have with the Skywatcher mount if possible.
  6. I think image shift in a SCT must be fairly variable between scopes. The shift in my C6 is noticeable, but minor enough that it doesn't disturb me, it's mostly a visual use scope. It has the factory focuser. My Edge HD 8" had very minimal shift with the factory focuser, and I've installed a Feathertouch on it. I see little, if any, change in shift when using it, although I can get a finer focus with less twiddling (the whole reason for adding it, IMO). For imaging, the shift hasn't bothered me, my mount will track past the meridian when imaging in that area, and if I do a flip, it's between image gathering, so I refocus anyway. The mirror locks do help, BTW.
  7. I can get three scopes into two pictures, best I can do without making new pics.
  8. For which scope? The Feathertouch I bought for my Edge HD8 came in a box about 4"x4"x10" and most of that space was air. It's a very nice focuser, a work of art, made a huge difference on my scope. If it is one of the models for a refractor, it will be a bigger box, but not as big as a shoebox at any rate.
  9. As stated above, the Baader film (Thousand Oaks also make a similar and equal product) over the lens of the camera in a suitable holder will allow photgraphing the Sun. It is called an energy reduction filter, it blocks over 99% of the solar energy so it won't damage the camera. HOWEVER-- if your camera has a separate viewfinder aperture, you MUST block it from the FRONT to prevent the solar energy from melting it or acting as a focuser and burn whatever is behind the viewfinder (such as your face, maybe). Several layers of black tape, or some dark card stock taped over it SECURELY will do. Do the same for any external light meter, if it doesn't meter through the camera lens.
  10. Meade = Lincoln/Caddy, WO = Rolls Royce. My GT81 amazes me every time I look through it. What issues have you heard about with the '71?
  11. I saw that thread as well. The one thing the optician can't do with an optics machine (and it changes the comparison between the eye and a telescope) is measure how the brain is compensating for visual aberration, and that varies with the individual because part of it is interpretive and can't be quantified. I look at SCT manufacture as a compromise between absolute optical perfection and what someone can reasonably afford. With today's technology, I'd rather have a finely tuned instrument made on an assembly line than a hand configured, although more optically perfect, instrument, because the likelihood of repairing the hand configured one back to its original specs if a major lens or mirror was damaged, is close to nil, without a huge cost involved, both of time and money. The hand configured one will be prohibitively expensive (to me at any rate) to begin with. The commercially manufactured ones are of course subject to tolerance ranges determined by by the limitations of the equipment used to make them. So, each and every primary mirror will vary within their tolerance limit, each and every secondary mirror the same, as well as the correctors. The optical qualities of each item can be individually checked by computer, and those computer readouts used to match the items in the most optically "perfect" combinations. When the parts are matched, further fine tuning can be done by hand; this could be as simple as rotating the secondary and /or corrector orientations with the primary once the tube is assembled, to hand grinding/polishing of one or more parts to more closely match them with each other; the degree of which will determine the price range of the item, since the more hand work performed, the greater the cost. Even with an instrument that tests "perfect" within the tolerance range of the test equipment, once sold, it will depend on the acuity of the user's vision as to just how good it is. You could have a user with average acuity and a telescope where everything fell precisely into place, and said user could not fully appreciate how good his scope was. You can also have someone with perfect vision and a perfect scope, and how they rave at the quality of the views they get; there's also the guy with perfect vision who happens to have the scope at the lower borders of the tolerance range, and how they complain that they'd never buy another product of that company, as well as a guy with poor vision and a poor scope, who can't see anything. Consumer products aim at price points and they are built to provide a level of quality that matches that. The better you want, the more it will cost; a level is reached where the cost is prohibitive to the point of nobody buying it and no manufacturer will approach that. Can't make a living that way.
  12. All the above. As you do it more, the thinking about setup, what you're going to look at, and how to go about it, get easier and more automatic, just like anything else that you practice doing. As your child gets older, her patience will improve, so it's not so much pressure trying to keep her attention and "riding herd" on her while you're getting things ready. If you haven't already done so, download the free Stellarium for those cloudy nights when you can't go outside. It's a great thing to play with, and a great learning tool as well. I use it to make "action lists" of things to focus on (pun intended) when I do get a good night for viewing, so I don't have to figure it out once outside. It allows you to find many objects in a particular area of sky so you're not wasting time skewing around the cosmos. I keep an eye on both short-term (5 day) and long-term (15-30 day) weather forecasts, to plan possible viewing nights around the other chores of living, and then revise them as those possible times approach with the daily forecast, and finally, by sticking my head out the window, so to speak. Always start viewing on a particular object with low power; it's easier to find the object in a wider field, if you don't have go-to, and then you can ramp up the magnification when you find something interesting. Another good reference for this is the book Turn Left at Orion, an invaluable addition to any astronomy text collection. Above all, approach the whole thing as a challenge and have fun with it. Some nights are washouts even in good weather, some nights you find a diamond mine of glittering objects to admire. Don't let the washouts keep you from searching for diamonds.
  13. I use this one:https://sourceforge.net/projects/virtualmoon/
  14. My comment was based on Celestron's own specs (maybe I should have said "useful" instead of "practical") as well as my efforts pushing the limit with my C6. Once past 300X, whatever the EP/accessory combination, the image dims, coma expands at the FOV borders into the 'meat' of the view, and a sharp focus becomes ever harder to achieve. My scopes are well-collimated, so that is playing a minimal part. I definitely agree that seeing conditions play a big part, but how many of us get consistently good seeing, wherever we are? Mine is usually better than average, with LP being the biggest hindrance below 30* from horizon. I now rarely view in my C6 at more than 200x, generally I leave the reducer in it, and for 'stronger' views, use the Edge 8. My choice of EPs was more mathematical, to allow a spread of magnification while minimizing duplicates with and without the Barlow, and to allow for multiple magnifications with a minimal collection of EP's. Certainly, as a hobbyist's experience and budget climbs, going to pure EP's will give better views than throwing Barlows into the mix.
  15. I think they are. It essentially doubles the number of Eyepieces (preferred term over lenses, except for barlows). I'd get a 2x shorty Barlow, and a 10mm and 18mm EP in addition to your 25mm. The Barlow will then give you 12.5mm with the 25mm in it, 9mm with the 18mm in it, and 5 with the 10mm in it; you'd then have 5mm (300x), 9mm (166x), 10mm (150x), 12.5mm (120x), 18mm (83x), and 25mm (60x) to modify your views; 5mm is about as small as is useful with the C6, you'd get 300X which is close to its max practical magnification. The 9, 10, and 12.5 are fairly close, but for only three EP's and a Barlow, you get a pretty good spread of magnification. The 6se is a good scope (C6). Later, if you want to widen the field a bit, consider the .63 reducer for it. For filters, a LPR/UHC is a good first one, and I like having a variable polarizer to cut the amount of light when looking at a bright Moon. You can adjust how bright you want the image, based on its phase.
  16. I wonder if the tip of that screw has been peened over from many times being tightened too much, and the threads are damaged so it won't unscrew from the housing.
  17. I know the AC to DC power supply for the CGE/CGX/AVX mounts supplies 4 amps, to safely supply those mounts with the 3 amps they usually require. I would think anything that can supply 2-3 amps would be sufficient for any mount smaller than those.
  18. Your mount is an upgraded version of a CG5, which I have. Both screws will limit movement in each direction. Since you have the front screw out, try pointing the mount higher and see if it may have been binding the rear screw, then see if the rear screw will back out. There should be nothing to lock that screw and prevent it from being removed
  19. You can also try lowering the leg(s) facing the direction you need, or elevating the one(s) in the rear, to tilt the entire mount and tripod. Make sure to remove the counterweight first so as not to cause the mount to fall over.
  20. He really had no idea what he found, he couldn't have told a SCT from a Newt from a refractor. It was just round and had glass in one end, that was about it. While we worked on the scope, we gave him a sort of primer on star-gazing with it, I showed him how to do a simple collimation check (defocusing on a star), and what to do if it was off. We're having a field event in a couple of weeks, weather permitting, he wants to bring it out so we can show him how to better use it. He'll bring all the other stuff he got with the scope so we can better evaluate his find. We think someone had bought it, used it for a while and was doing AP with it, since it had a motorized autofocuser on it, plus the guide scope; but got frustrated when they "broke" it trying to install Bob's Knobs. I suppose it could also have been a donation from a deceased's estate. Hard to say, but what we saw was in great shape, just obvious it had been sitting a while. I told him that once a more experienced viewer could check out the quality of the views, if it was off at all, it would still be well worth his money to return it to Celestron to have everything wrong with it corrected (which won't be much, I think) We talked about his find for an hour after he left, none of us could get our head around a find like this.
  21. Tonight our club had one of its twice-monthly public viewings; weather was cruddy, didn't figure there would be anything to see, so I almost didn't go. When I got there, just a couple of visitors and four of us members. Two guys were messing at a table with a Celestron Nexstar 8se. Seems one of the two guys (visitor) had just bought it and needed some help with it as he didn't really know much about it. Sound familiar? It gets better....a LOT better. The tube 's secondary mirror was laying inside the tube, where it had fallen out of its holder when someone (not the new owner) had tried installing Bob's Knobs and apparently didn't follow the instructions to do one screw at a time. The new owner didn't know how to remove the corrector to fix things. He also told us he had a bunch more stuff at home that he'd bought with the telescope: a reducer/corrector, a diagonal, four EP's, a 9x50 guide scope and a few items he wasn't sure what they were. The tube had a motorized focuser on it. The kicker (drumroll, please): he'd bought the whole thing at his local Salvation Army outlet for $20 USD. He said he shopped there frequently for odds and ends, saw this on a table, and decided to buy it, his girlfriend expressed an interest in astronomy. Yes, Twenty dollars. The OTA is silver, not orange; it has the XLT coatings, the smooth back and the alt-az mount has the nexstar controller, the clear plastic film over the display was still there; there were no cable inputs on the top of the azimuth axis cover, just a removable cover with what looked like a battery compartment under it, but no battery connections. Anybody have a guess to its age/era? We couldn't operate the drive, no power pack with him, but it looked to be in great shape. I took the corrector off after marking it for reassembly, got the secondary mirror out and cleaned it, and looked closely at the primary. It had just a couple of small smudges, and a scratch that looked like the secondary might have hit it when it fell out, but nothing bad enough to mar the focus or image. After getting the secondary back in its carrier and cleaning the inside of the corrector, I reassembled it and did a collimation. He's going to bring it to our next outing and we'll help him learn to use it and further collimate it. He was very grateful, and was getting quite excited about his new find after we told him what it was all worth. Given his descriptions of what he had at home, and the condition of what he'd brought, he probably has about $2500 worth of telescope stuff. For $20. I'm going to start scouring every Salvation Army store I can find.
  22. Think of altitude-azimuth coordinates as the location of your object relative to where you are standing on earth. No matter where on the planet you're standing, the coordinate's zero point is based on YOU and the direction you're pointed. Altitude will be the height of an object above the horizon in the direction you're looking, and azimuth will be the off-angle to the right or left of a vertical altitude line drawn from the horizon in the direction you're pointed. In degrees, where a specific object will be as measured in height above the horizon (alt) and offset (azimuth) will change with your position on Earth. A celestial coordinate does not change, no matter where you are standing. The celestial coordinate system (Declination and Right Ascension) is based on the planet and its position in space. Where alt-az is dependent on where you stand, Dec/RA doesn't change with your position. If you consider the lines of latitude and longitude as an earth coordinate system, the celestial coordinates are just the lines of latitude and longitude extended into space. Latitude is the same as Declination, Longitude is the same as Right Ascension. Where Latitude has the Equator, so does the celestial system, to delineate where North and South meet. Where Longitude has the Prime Meridian to determine a zero point to number from, so does the celestial coordinates have the First Point of Aries (which oddly enough is in Pisces) to determine where Right Ascension is numbered from. The First Point of Ares is one of two points where the plane of the ecliptic crosses the celestial equator. Opposite this is the First Point of Libra, which is 180 degrees away on the ecliptic and celestial equator. Brantuk has the best way to see how they are alike/different. You can choose either or both systems to show on Stellarium. @ Binocular Sky: Love the umbrella. Is this a star chart for rainy nights? Where can I find one of those?
  23. Main reason they quit working in the cold is the batteries. As the batteries cool, voltage drops and the laser is sensitive to the lower voltage. I keep mine either wrapped in my hand or in a pocket inside my jacket. Fresh batteries in the cold also help. 5mW is the most powerful you can find for consumer use. No reason to need more unless you're trying to burn something. We have medical grade lasers at work (surgery), in several types; CO2 and Holmium, and they have outputs up to 10W. You can punch a hole in a tongue depressor in less than a second with the CO2 version.
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