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Messages - precaregmo

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1
Beginners Forum / Re: Help with my new "old" free sky cannon.
« on: February 09, 2018, 02:01:40 AM »
Since nobody has commented... Collimation is pretty easy and there are dozens and dozens of threads here and videos out there about how to do it. If you're patient you can get a laser collimator used here or on Astromart. Since your primary mirror is center-spotted (that little donut sticker in the center), a laser makes collimation fast and easy:
Look into your focuser without an eye piece and be sure you can see the whole secondary mirror (that it's basically centered "under" the focuser"), and that you can see the entire primary reflected in the secondary.
Put the collimator in your focuser.
Fiddle with the adjustment screws behind the secondary mirror until the laser shines in the middle of the "donut" on your primary mirror.
Move to the back or your scope and fiddle with the collimation adjustment knobs until the laser shines back on itself. You can tell when the laser is "shining back on itself" when the beam is reflected back to the center or the shiny silver surface of the collimator. Once you've seen a collimator, you'll know exactly what I mean.
https://optcorp.com/...d&isp_ref_pos=1 (note that this is not an endorsement for Opt, although I like Opt, but they have an inexpensive laser).
You can do the same thing with a Cheshire tool, but you have to look for different things and it's hard for me to describe in writing, so I won't try. Besides, a new Cheshire costs about the same as a used laser. For almost free, you can also make a collimation cap by punching a small hole in an old 35mm film canister (almost to perfect size to fit into a 1-1/4" focuser, or a 1-1/4" x 2" adapter). The collimation process and what to look for is similar to using a Cheshire.

I agree with Izar187: mirror cleaning isn't really your top priority. I'd spend my time cleaning up the tube and base, figuring out what you want to do about a finder and getting things collimated. You'll be able to observe then, even with dirty mirrors. From the photo you posted I think you have a 2" focuser. You can find 1-1/4" x 2" adapters on the internet or at astronomy retailers. Then you'll be able to use almost any eye piece you can imaging. Looks like you have two sets of rings: the pair that are close together are intended for a finder, the two that are farther apart look like they were intended for a guide scope. Why anyone would put a guide scope on a Dobsonian-mounted scope is beyond me.

2
Beginners Forum / Re: Beginner scope for quick viewing
« on: February 08, 2018, 07:16:39 PM »
+1 for the Zhumell 8" dob, laser collimator, finder, 2 eyepieces, 2 speed 2" focuser @ $399.

Get as much aperture as you can afford because the greater the aperture the greater the detail you can see .

3
Reflectors Telescopes Forum / Re: Orion UK VX6L - experiences?
« on: February 04, 2018, 12:09:04 PM »
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I have a GPD2 and was wondering if the the 8 in F4.5 scope would fit on it and the dob mount. How is eyepiece placement on your mount? Are you able to sit while observing?

It depends which angle the telescope has. If it is in the position like above on my picture you have to stand but that is no problem for me. I even made the tripod higher to easily stand. :-) In this position I can change the 6" f/8 by my 4" f/9 APO or 80 f/15 achromat refractor and can watch and sit.So I can sit befin my refractors or stand next to my newton reflectors.
Clear skies,
 Roland

4
Keep in mind that planets, unlike stars, have an eastwardproper motion and even if everything is perfectly aligned, will drift out of the eyepieceFOV if your observing session is long enough. Alnitak is an excellent choice for drift alignment since it is bright and almost exactly on the Celestial Equator. Unfortunately, Orion is not visible now. Currently, the two best stars for drift PA are Regulus in Leo and Spica in Virgo.

5
Sharpcap (free) has a polar alignment function.

PHD2 (free) has a polar alignment function.

Does anyone know if anyone has written a polar alignment software tool for Macs?

FWIW I have been told that the PoleMaster now officially supports Macs.

Also FWIW, I am a Windoze user but not a win-bigot.

I hate all OS's equally.

6
ATM, Optics and DIY Forum / Re: Circular Parabolization Stroke
« on: January 31, 2018, 09:36:05 AM »
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Right. Finish polishing, knowing you're not doing anything terribly wrong.

So close now! A bit of TDE, and under correction, but not bad.Almost polished out. The waves are heat currents, its still warm from polishing.

7
ATM, Optics and DIY Forum / Re: Truss Poles - To paint or not to paint
« on: January 31, 2018, 09:29:53 AM »
Foam pipe insulation with heat shrink tubing to the ends, look good and keeps the ends catching on things.....
Nice and warm to hold onto when the temperature plummets...
Attached Thumbnails


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I prefer the rubber eyeguard on the ES40. Flicking it down allows easy eyeglass use and I find eye positioning easy with the guard up. It all depends on the shape of your face.

9
Beginners Forum / Re: Oh wow!
« on: January 31, 2018, 07:33:03 AM »
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Back to Jupiter's moons...a week or so ago I was setting up early in the morning and went to Jupiter. I used the moons to fine tune my focusing, trying to get the smallest pinpoint/disk I could muster, when I noticed what I thought was an internal reflection in my eyepiece. It turned out to be two of the moons almost directly in top of the other, similar to seeing a very close double star. In all my years of observing, I'd never seen two of the moons appear that close to each other.


Jupiter's moons put on an ever changing show every night that never fails to please. The shadows going across the planet's surface is my favorite 'moon' sight, while Jupiter's disc is my favorite sky object.

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Beginners Forum / Re: Do I need both?
« on: January 31, 2018, 04:54:47 AM »
You'd be hard-pressed to replace either one of those telescopes if you changed your mind later. Therefore, keep both. I'd say you hit the jackpot. You can add a motor to the Towa (Circle-T) refractor's equatorial mount and track objects automatically, hands-free, and the main lens, the doublet, of the refractor is of above-average quality; made in Japan.

11
Light Pollution Topics / Re: Bortle scale accuracy?
« on: January 31, 2018, 03:29:28 AM »
Thanks Brooks- it sounds like Mag 8 is the extreme limit..... in your experience, what's the faintest and/or farthest away DSO anyone has seen visually?

12
Stop by NEAF on 8 or 9 April in Suffern, NY. Largest astronomy equipment show in the world. You can try out almost anything, and get good prices on it.

13
Beginners Forum / Re: Maksutov? Schmidt?
« on: January 31, 2018, 12:02:57 AM »
Skywatcher has a 180/1000 Mak-Newt too, but I should put it at least on an Eq6.

14
Quote
Siebert has a 1X Optical corrector.
You could ask him about it.
I used to own one and it works. Takes a bit of effort to figure out how it works and it has the home-shop-made look to it. But I had no problem using it in an MN66.
Which leads me to think: a 1X OCA that extends back focus by the typical 5 inches required by binoviewers shouldn't require alien tech (or maybe it does, I'm no optical engineer). Why does TV or ES not have such a product? Baader has a Newtonian OCA but it provides a 1.7x magnification and is a coma corrector as well.
Tanveer

15
General Astronomy & Observing / Re: light pollution zones differences
« on: January 29, 2018, 11:31:52 PM »
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Tony suggests that just seeing the glow both sides of the Great Rift in Cygnus along with M8 and 24 with the naked eye is enough to make the claim. However, to me - and I think that most other old-timers would agree - that is just detecting detached bits and pieces, not truly seeing the Milky Way as it really is, or as a whole. So, if you cannot trace the outline of the Milky Way continuously across at least a goodly portion of the summer sky when it is near your meridian then I cannot accept that you as really able to honestly claim to be seeing it.
Words are slippery things. If you want to get technical, nobody can see the Milky Way "as it really is," since well over 90% of it is completely hidden by dust when viewed from the vicinity of our Sun.

I sometimes phrases such as "see the Milky Way as it should be seen" or "see the Milky Way in all its glory." That can only be done at sites with little or no light pollution and when the transparency is excellent. (And when the zodiacal light isn't obscuring part of the view!)

What counts as "a goodly portion of the summer sky?" 180 degrees? 150 degrees?

If you can see the Milky Way on both sides of the Great Rift, and if (around latitude 40N) you can see M24, then you can also trace the outline of the Milky Way continuously for more than 90 degrees. Is that "goodly?" Your call.

Of course, "outline of the Milky Way" is totally subjective. It appears wider the darker the sky. Technically, it has no border and no outline. We live inside it, so it covers the entire sky.

If you want to use the visibility of the Milky Way as an indicator of light pollution, you need to be a bit more precise. And in fact, the Bortle Scale is fairly precise.

The description for Class 6 says: "Any indications of the Milky Way are apparent only toward the zenith." My experience in Lincoln, MA is clearly better than that. The description for Class 5 says: "The Milky Way is very weak or invisible near the horizon and looks rather washed out overhead." That matches my experience in Lincoln quite nicely.

But on other criteria, Lincoln is somewhere between Class 6 or even Class 7. M31 is obvious even to complete novices, but seeing M33 without optical aid is absolutely inconceivable. The limiting stellar magnitude (for me) is somewhere between 5.0 and 5.5.

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