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jonnyastro
Carpal Tunnel
Reged: 02/14/06
Posts: 3449
Loc: Pittsburgh, PA
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I am loving my new CG5. Due to illness last nite was the first time i really got it out there, and man it is a nice platform for my 4 inch refractor. Quite accurate too. I was wondering though, if i purchase the optional polar finder, will i be able to align with that, and than choose the quick align option, to bypass needing to use calibration stars? Thanks in advance!
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celestial_search
Carpal Tunnel
Reged: 11/18/04
Posts: 2531
Loc: Iowa, USA
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I bought one three years ago. You have to "align" it with the mount. I found that if I "aimed" the mount at Polaris and did a good three-star alignment that I never used the polar scope. If you have a mount that you place in the same spot all the time (leg locations marked) and you want to shoot some astrophotos with a DSLR camera, you may use it to help get a more accurate alignment (i.e. less drift), but I think that if you aim the "hole" in the mount where the polar scope goes (at the NCP) and do a good three star alignment that you will like not use it. I bought mine for $40 and still have it.
I do use the one that came with my EQ-6 mount, but that mount is on a pier and once I aligned it, it stays aligned (and the polar scope came with the mount).
I've thought about selling my CG-5 polar scope, but likely will keep it as it would be a hassle for $25 or so to package and ship it.
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Frank
C-11 XLT
8" f/6 Newt on GEM
Tak FS-102II
SV 80L Triplet APO
EQ-6 Mount on pier in backyard observatory (EQMOD)
CG-5 AS (GOTO)
SBIG ST-5C CCD and Canon Rebel XSI
SSAG
Oberwerk 15X70s and Pentax 10X21s
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1965healey
Post Laureate
Reged: 06/23/07
Posts: 3134
Loc: San Antonio, TX
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The short answer is no. The Celestron one is just a crosshair scope and is pretty useless. The Orion one is a bit more sophisticated and has an engraved reticle with cool stuff on it. Probably an illusion that it'll get you any better aligned that just peeking thru the hole and finding Polaris and centering it. I got one cheap but haven't tried it yet. My gut tells me I'll spend an hour messing with it and from that point on it'll just be a "hood ornament" because it will be more trouble than it's worth. The calibration stars are probably gonna get you aligned much better. Crilly is out there somewhere and I'm sure he'll jump in and set us straight.
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1965Healey (Karen)
Woodlawn Lake Observatory
Celestron CPC 800/FT MIcro/APT Wedge
SV NHNG 80mm #0261/CG5-GT
Celestron Omni 150 XLT
Losmandy rails/rings
Starizona CWeight system
Celestron Neximage
Sony a100 DSLR/ZigView S2
Meade DS60's w/Autostar (2)
Meade LPI/Meade DSI-C/DSI ProII
750cc Honda Shadow Spirit (Thanks Dad!)
1965 Austin Healey 3000 MKIII
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jonnyastro
Carpal Tunnel
Reged: 02/14/06
Posts: 3449
Loc: Pittsburgh, PA
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Thanks brother you just saved me 50 bucks!
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jrcrilly
Refractor wienie no more
Reged: 04/30/03
Posts: 25195
Loc: NE Ohio
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Quote:
Probably an illusion that it'll get you any better aligned that just peeking thru the hole and finding Polaris and centering it.
It depends on what your goal is. If you want to image without drift aligning then you want the best polar alignment you can get from the start; a properly used, properly aligned polar alignment scope will give you that. Some will get you very, very close with little effort (Tak, for example). Some will get you fairly close, but only if well centered within the mount and rotated to the proper orientation for the time and date (pretty much everyone else). This requires extra effort and time to be expended.
For visual use, the polar alignment error caused by simply centering Polaris in the polar scope (or in the hole where one would go) is plenty close enough for good goto and visual tracking performance.
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John C
Urban Observatory
A&M/Astreya 76mm F/6 APO
TMB/LOMO 80mm F/7.5 APO
Tak FSQ-106N F/5 APO
Meade 178ED F/9 "APO"
Meade ETX-125AT
C14
Teeter 20" F/3.8 truss Newt w/ServoCat
CI-700, NJP, GPDX/SS2KPC, CG5-GT
ST-10XME, DSI Pro
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1965healey
Post Laureate
Reged: 06/23/07
Posts: 3134
Loc: San Antonio, TX
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Thank you John! Sometimes I think we don't state what the GOAL is when we ask the question, visual or AP, big difference.
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1965Healey (Karen)
Woodlawn Lake Observatory
Celestron CPC 800/FT MIcro/APT Wedge
SV NHNG 80mm #0261/CG5-GT
Celestron Omni 150 XLT
Losmandy rails/rings
Starizona CWeight system
Celestron Neximage
Sony a100 DSLR/ZigView S2
Meade DS60's w/Autostar (2)
Meade LPI/Meade DSI-C/DSI ProII
750cc Honda Shadow Spirit (Thanks Dad!)
1965 Austin Healey 3000 MKIII
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ericjacob613
Photon Hog
Reged: 05/25/07
Posts: 3754
Loc: Santa Barbara CA
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I first bought a CG5 clone with a polar scope which had a 24-hour clock face on its reticle. After adjusting the reticle to center it, I got dead-on alignments in just minutes.
When I got a bona-fide CG5 I put that same polar scope in it. Setup including polar alignment takes only minutes, and my shutter begins to click as soon as it's dark. No calibration stars, no alignment stars. Just a quick-align and away I go. As long as I have that little polar scope I'll never drift align.
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"Is that boy on the moon again?" - Gumby's Dad.
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Pasquale
Encrypted
Reged: 10/12/05
Posts: 2219
Loc: Olympia, Washington
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I'm still trying to figure out how to use mine! I've read the directions over and over, but for some dumb reason, it's just not clicking with me. It'd be so much easier if I could just watch someone do it once, then I'd understand. Anyone know of a good tutorial/video for the Vixen PAS?
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Pasquale
Go Seahawks!
NexStar 9.25 GPS / SkyAlign
Stellarvue SV102ED
WO ZS80FD Anniversary
WO ZS66ED Triplet
Vixen Sphinx SXW
Canon EOS XT/350D, Meade DSI, NexImager
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RandallK
Pooh-Bah
Reged: 11/10/06
Posts: 1003
Loc: Nanaimo, B. C. Canada
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On my HEQ5 there's a reticle with Cassiopeia and Ursa Major with a symbol of Polaris on the outer cirlcle. If the index marker ring is set correctly and it wasn't on mine, you have to calibrate it.* When you use the correct date on the date scale, the correct longitude offset (those little numbers along with E & W) also on the date scale, and set the right time (in Standard Time always) with the RA circle, Then...you move the mount (eg. by the counterweight shaft), so that the RA indcates 0 at the Index Marker.
Peer through the polarscope and adjust the fine azimuth knobs so that Polaris is superimposed over the Polaris indicator on the reticle. This gives you correct hour angle of Polaris. There is a Polaris Finder program available on the web to verify your setting, however if you use the program, you should key in your latitude and longitude each time you use the program, I found that the program doesn't retain the settings. I checked for different times on different months, and what showed in the Polarscope also agreed with the Polar Finder program.
This is the hardest thing to explain, but in reality it only takes about a minute to do this, but your Index Marker Ring (the one with the vertical white marker) must be set correctly. You only have to do this once unless it comes loose.
Because I'm going to be doing CCD imaging, I painfully read this over and over and over until I finally got it, but for visual, you really dont't need to do all of this.
* The easiest way to calibrate the index marker is to check it out the way it is by setting up the date, time, etc., then peer through the polarfinder and see how much Polaris is away from it's correct position (hour angle) by checking it with a Polar Finder Program. If it's in the right hour positon, then you're OK, if it's not, then you will have to undo the setscrew on the Index Marker Ring and move it which ever way Polaris is out. Keep repeating the procedure until Polaris is in the correct hour angle positon, then prove it by doing random time and date settings, comparing it to the Polar Finder program. Whew!!!!!
Edited by RandallK (01/04/08 07:16 PM)
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