Date
1 - 15 of 15
Using RAPAS for first time - how do I know it is Polaris?
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Shailesh Trivedi
I am using the RAPAS for the first time to polar align my Mach2. I live in Bortle 6 skies (suburban Sacramento, CA). My question is that after moving the mount and tripod, I was finally able to get a very faint star in the reticle. The faint star was so faint, that when I turned on the reticle light, I could not see it. How do I know it is Polaris?
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Roland Christen
It's probably the wrong star. Polaris is bright enough to be seen with the reticle on in my Bortle 10 skies.
Rolando
-----Original Message-----
From: Shailesh Trivedi <shailesh.trivedi@...> To: main@ap-gto.groups.io Sent: Fri, Apr 8, 2022 12:24 pm Subject: [ap-gto] Using RAPAS for first time - how do I know it is Polaris? I am using the RAPAS for the first time to polar align my Mach2. I live in Bortle 6 skies (suburban Sacramento, CA). My question is that after moving the mount and tripod, I was finally able to get a very faint star in the reticle. The faint star was so faint, that when I turned on the reticle light, I could not see it. How do I know it is Polaris?
-- Roland Christen Astro-Physics |
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midmoastro
I cannot be certain, but its sounds like you may have had the wrong star. I live in bortle 5 and have no issues with Polaris being too dim in my RAPAS.
Even with the light on low or medium its still easily viewable for me unless its behind a line. I suppose that could manifest different for others. Most of my bright lights are to the west, not north. Can you see Polaris with the naked eye? With my altitude set, I am able to loosen the three screws at the base of the Mach2 where it connects to my Berlebach tripod and carefully turn it left and right until I see Polaris in my view. Once I find it I tighten those three base screws, then use azimuth adjustments and the tommy bar to dial it in. I would start by finding your location latitude, then use the altitude adjuster to try and match that as best as you can. Once you set up you mount and eyeball Polaris, you should be able to sweep left and right and find it. It may take some trial and error but once you find it, unless you hit the tommy bar or move locations, you shouldn't have to mess with it again. |
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I agree. It is probably the wrong star. I am a recent adopter of the RAPAS which I think it great by the way and I just kept kneeling behind the mount until I found something that looked goldilocks bright. Not too bright and not too dim. It works great once you find the star, and then use something like Sharpcap to align with the pole with accuracy, and then adjust the push pull screws to get polaris where it belongs. From that point on, I get very close to the pole every time. Good luck.
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You should be able to set your altitude to your latitude and be close enough to only move east/west to find polaris Brian On Fri, Apr 8, 2022 at 1:06 PM Emilio J. Robau, P.E. <ejr@...> wrote: I agree. It is probably the wrong star. I am a recent adopter of the RAPAS which I think it great by the way and I just kept kneeling behind the mount until I found something that looked goldilocks bright. Not too bright and not too dim. It works great once you find the star, and then use something like Sharpcap to align with the pole with accuracy, and then adjust the push pull screws to get polaris where it belongs. From that point on, I get very close to the pole every time. Good luck. --
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Dean S
I found it best to sight Polaris thru the mount before putting in the finder scope.
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On Apr 8, 2022, at 3:39 PM, Roland Christen via groups.io <chris1011@...> wrote:
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Terri Zittritsch
Everyone else has great suggestions.. you could also do a daytime telescope alignment as well (see your manual or web search) using the sun with filter or in twilight to a bright star. This will put the mount more than close enough to ensure your RAPAS has polaris in the field. It'll be a very bright pinprick of a star in the RAPAS and easy to see well before astronomical darkness. The star will be so finely focused that it can be obscured by the reticle markings so if you don't immediately see it give a small move of the azimuth or altitude.
Terri |
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Jeffc
Are you planning on doing astrophotography? If so , you could use a camera , and one of the programs that will provide guided polar alignment… PemPro, SharpCap, Nina.
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Then once you know the mount IS polar aligned, check the Rapas. If needed, you can use the push pull screws on the RAPM2 to precisely align the RAPAS for your mount. On Apr 8, 2022, at 10:24 AM, Shailesh Trivedi <shailesh.trivedi@...> wrote:
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fernandorivera3
I make sure I can see Polaris thru the bore of my 1200 GTO R.A. axis before I put the scope on, fine balance, power up the mount, etc.
Fernando |
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Fernando,
Yes, I forgot to mention that. I agree and this was how I first sighted the mount. Very important comment. Then once you get everything set, you know what to look for and things are aligned so it is pretty easy thereafter. |
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fernandorivera3
Shailesh try using Sky Safari planetarium app on your smartphone or tablet. When the program is running with GPS turned on look at the screen- it will help you find the north star.
Polaris is one of the brightest stars in the northern hemisphere. I am even able to see it from my miserable downtown location where at night much of the sky is drowned out by EGREGIOUS LED billboards light pollution that continues to get worse as time goes on 😟 Fernando |
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I find that the problem is that the field of view of the RAPAS is rather small. Initially, I either remove the scope and site through the center of the mount or I attach Polemaster to the AP1100 (I have to move it to position 3 to do this otherwise the trailing cable will hit the gear box). I'm usually on my driveway, so once I've found Polaris, I chalk the driveway around the wheels on my Scope buggy and I leave the mount parked as it was in that position when I finish for the night. Once I've done that I can just return to my chalk marks and use the RAPAS and the AP app that shows where Polaris should be for my time and location.
Mark |
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Shailesh Trivedi
Thank you very much for all your insights. The moon was interfering with my sighting. Two nights ago, I waited until 2am for the moon to go below the horizon and I was able to then get to what I think is Polaris and the reticle LED light of the RAPAs did not drown out the star. Next night alas with the moon brighter, I was only able to issue a GOTO with my keypad to the moon, all other spring galaxies showed up as fuzzy patches.
I think I have the PA in a god place for now. Once the moon goes down, I will try again. Can a keypad be used to create a pointing model? I seem to recall a thread from Roland that it can, maybe it is in the manual and I will to look. Thank you again to everyone. Shailesh |
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I have a simple and inexpensive red dot finder on all my scopes. As soon as I see Polaris with the naked eye, I do a crude alignment of the mount using the finder. Takes about 20 seconds and it always gets me close enough for RAPAS or camera based polar alignment to take over. You can take the finder off after your done with it or just leave it on so you can get a feel where those dim pixels in your imaging train are coming from in the night sky.
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Ben Koltenbah
Your experience is not at all uncommon. I began my astrophotography obession - I mean hobby - many years ago with a cheap mount long before I discovered Astro-Physics products. This one had a permanently fixed polar scope along its "bore sight". I had to crouch down in an awkward position and crane my neck upward to look through it. I recall my first night trying to align with Polaris, and nothing stayed on track the whole night even after repeating several times. It was only later that I realized I was polar aligning on Kochab! That's a sizeable error.
Once I graduated to my first AP mount, I immediately ordered the RAPAS, and my neck has since been saved. When I set up the mount, particularly in the daytime, I use a compass to roughly place the mount pointing north. If you do that, don't forgot to account for your magnetic declination. I am usually able to roughly align so that Polaris is within the RAPAS scope's field of view. I also look for Polaris at dusk and make sure my mount is roughly aligned with it. Soon this will be second nature for you. (No more Kochab!) Good luck! Best Regards, Ben |
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