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About Buzzard75

  • Rank
    Star Forming

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  • Location
    New Bern, NC
  1. Getting started

    I have a 12" truss type dob. Collimation is a piece of cake once you get the hang of it. Anytime you setup your scope, one of the first things you should do is check the collimation. Even small bumps can knock the secondary or the primary mirror out of collimation. A fraction of a millimeter of movement by either can mean even greater error over the focal length of the tube. As I have to disassemble mine every time, it's a given for me. Sometimes it's off a hair and I don't bother with it, other times it's off by quite a bit. Laser collimators are great and I use one. They make collimation a little bit quicker. They do need to be checked for collimation from time to time, which is also easy enough to do. I do recommend you get yourself either a Cheshire and/or use a collimation cap though, for two reasons. One, you'll need it for alining the secondary with the focuser. You can't do that with a laser. Two, knowing how to use a Cheshire and/or a collimation cap will help you better understand the collimation process. I will often times collimate using all three to check, double check, and triple check my collimation. Is it absolutely necessary that I check it with all three? No, but since I primarily use my laser, if I check with the other two, I know there's nothing wrong with my laser. If I check with the Cheshire or the collimation cap and it's not right, I know I need to recollimate my laser. But since I know how to use a Cheshire and collimation cap, I'm not dead in the water. I've recently had my first experience with what I believe to be coma. I only experience it with a long focal length, wide FOV eyepiece. I don't have a problem with my other eyepieces. I haven't yet checked to determine if what I'm seeing is coma or if it's astigmatism. My guess is coma at this point. I honestly wouldn't worry about it until you actually experience it. In my case, it's just a specific combination of eyepiece and telescope and isn't always a problem and it may not be for you either. Even if you do see it, it still may not be such an issue that you feel you need to spend the money to correct it.
  2. Coma Correction

    Yes, thank you for the links and the pictures. Reading Louis' method and seeing the graphic Laowhoo had posted is exactly what I had pictured in my mind for an astigmatism check. I'm fairly certain what I was seeing was coma, but I have yet to confirm. Haven't had too many clear nights. Just trying to envision it in my head I seem to recall they were bunched up on one side and then stretching outward just like in the focused image of coma so I'm fairly confident. Hopefully I'll get a chance to get it out this weekend, but it's not looking like the weather wants to cooperate.
  3. I couldn't find a decent red one in any of my local stores. In the end I bought a small Bushnell flashlight for around $15. It's only 50 lumens, about 3.5" long and runs off a single AAA battery. I then painted the end red with about 6 coats of red nail varnish that I bought at the same store for about $1. I made a paracord lanyard for it and hang it around my neck. I purposefully bought it because it was so dim. Hanging around my neck, it's perfect for looking at star charts, planispheres and reading astro books. The dimmer and redder the better.
  4. Outreach Laser Pointer

    I use Z-bolt Galaxy series. They have three models, Ruby (red), Emerald (green) and Sapphire (blue). The red isn't good for much other than indoor, classroom, or presentation work. The green and blue however, are extremely bright and visible at night. These are not cheap laser pointer though. They are very powerful with an extremely long range and could legitimately blind someone. As JOC said, lasers can be dangerous for pilots and you must use extreme caution with these. If I even see a plane, I won't use it until it's passed. If I see members of the public using their own pointers at our events, I recommend they not or at least be mindful of where they're pointing and that they under no circumstances let their children use them at our events.
  5. Coma Correction

    Thanks for all the responses. The next time I get a chance to take it out, I'll try Louis' method and at our next club event I'll see if anyone already has a corrector I can try out. I've seen GSO, Explore Scientific, and Tele Vue all have their own coma corrector. I'm sure there are others. If that's what I need, what would be the benefit of getting a ridiculously expensive TV over the other two? Or is there a reason I may want to choose either the GSO or the ES besides saving some money?
  6. Coma Correction

    Thank you! I was hoping someone would chime in with a method to try and determine the difference. Even with all my research, I still don't think I'm educated enough to be able to discern the difference just by a basic visual observation. I needed some way to test and determine what I'm actually seeing. As it seems to be the nature of a fast Newtonian reflector and wide FOV, and based on what I THINK I'm seeing, I'm guessing it's coma. I'm going to try the method suggested by Louis and see if I can figure it out first before I go spending money on a coma corrector.
  7. Coma Correction

    I received an ES 30mm 82-series eyepiece for Christmas and have only had one opportunity to use it since. I used it in my Orion 12" dob. While viewing the Orion Nebula I noted that the stars towards the core of the Trapezium were fairly well focused, however, the ones towards the edge tended to be more stretched. I'm not an expert on the matter and not having really seen an example of it before, it's my understanding this is what coma looks like and is fairly common in fast scopes such as mine, which is an f/5. I didn't see any scattering of color so I don't believe it's chromatic aberration. The fast scope coupled with the wide field of view from the eyepiece just seems to be a recipe for disaster. I have a handful of other eyepieces, an ES 14mm 82-series included, and don't seem to have the issue with any other eyepiece. Has anyone else experienced the same issue with the combination of a large aperture f/5 and such a wide FOV, long focal length eyepiece? Am I misinterpreting what I'm seeing? Do I just need to buy a coma corrector and go on my merry way?
  8. Prepping for 2024

    It really is a good debate and I appreciate all the input. Being able to lay out all the pros and cons for each solution from people who have experience using all different types is extremely useful for me and I'm sure others who are interested as well. Paul, you also mentioned in one of your previous comments about getting a 100mm scope and it needing proper mounting. Is there a reason you wouldn't be able to set it up on a regular tripod for just some quick, unguided observations?
  9. Prepping for 2024

    I know I don't NEED to wait until 2024 for the eclipse to view the sun in H-alpha and I know I don't NEED a solar scope to view the eclipse, however, I want to make sure I'm prepared for it. That's all. Viewing the eclipse in H-alpha was certainly an amazing sight and I've got some time before the next one to save up the funds or slowly acquire the equipment. Right now I'm just trying to decide if I want to use the equipment I already have and just get some filters, get something dedicated, or get a completely new setup that I can use for both H-alpha and possibly astrophotography. I'm leaning towards the latter, it's just going to be a lot more expensive than the other two options.
  10. Foggy lense

    I had issues with my eyepieces fogging up last night myself. I got my scope set up and my dew heaters going, but didn't think to wrap one around my eyepiece. So after a couple hours it fogged up. I got out my eyepiece dew heater and wrapped it and then stuffed it inside my coat. After a few minutes it cleared right up. I also have a small USB powered heating pad inside my eyepiece case, but forgot to bring my small rechargeable USB power supply.
  11. Orion Nebula in Winter

    I live in a pretty small city that still has a considerable amount of light pollution and even I have a hard time with my 12". The darker the skies the better. You'll be amazed and just how much detail you can see even with the smallest of scopes.
  12. First Light for new EP's

    I've had my new eyepiece since Christmas and haven't had an opportunity to use it yet. I'm extremely jealous. When I do, Orion will be my first target with Pleiades shortly to follow.
  13. Prepping for 2024

    Thanks guys. My dob is a GoTo so it should be able to track with minimal corrections. I would definitely stop down the aperture with an off-axis ERF. I can't say I've ever seen or heard of anyone doing H-alpha with a dob before myself either, which is why I was asking before I even started going down that road. DayStar Quarks certainly aren't cheap though and I figure by the time I spend the money on one of those and an off-axis ERF, I could probably buy a dedicated solar scope. Just not sure I want to have more telescopes sitting around that serve a specific purpose. Maybe a refractor would be a better option and then I could potentially use it for some astrophotography work as well. Something to think about I guess.
  14. Help with apps

    As long as your phone can get a GPS signal you're good. All the data is in the app, it doesn't require a data connection to run. I think that's what you're asking.
  15. Help with apps

    I use SkySafari 5 Pro with my GoTo. I'd assume the Android and iOS versions are similar, if not identical.