WNCAGC
sage
Reged: 06/25/08
Posts: 259
Loc: NC Mountains (God's country)
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Well everyone knows my dilemma with changing out the stock collimation screws to Bob Knob's. If not the quick story is, changed out per instructions and the vivid clarity was shot to you know what 
That being said I frantically asked here what to do and how to get it back knowing the old addage, "If it ain't broke, don't fix it!" Well having the knobs on hand and waiting til the scope needs to be collimated were too much for me like a kid the night before Christmas. So I did as the instructions stated and what a pain in the keaster! Totally $%^& up to say the least. And to think I use to build road bikes from the ground up with percision parts! 
But a scope is not a bike to say the least. So after realizing that I was a dumba$$, I look for help and got alot of useful answers.
But the scope has yet to be crystal clear since. So that means the collimation is still off slightly. In other words when viewing outside during the day I would routinely focus in on a tree through the valley about 700 yards away and see every detail of the bark on the tree. Now I can see the tree trunk with halfway clarity but the bark is not discernable like before!
So after nervous breakdowns over and over I bought a laser collimation tool. My thought was that while researching laser collimators and the general consensus is that they get you in the ballpark but star collimation to get it finely tuned this is what I would do. Well it does just that do a degree, I can now see the bands on Jupiter slightly with a slight haze, so I know it needs fine tuning a bit more. Now here is the problem, I can't get the darn thing to that point! Seems like it just won't get there. So I have found a local camera store that says they collimate scopes and may give them a try. I have tried night after night to collimate a star and when the star out of focus and that darn center dark disc looks perfectly centered and I re-focus, voila, still slightly off! What the heck.................centered is centered isn't it?????
Apparently not!!!!!!!!!! So I am at wits end and need professional help.
My question since they claim they collimate a scope and they came highly recommended..............what question should I ask them when I drop the scope off to make sure they know what they are doing, like I know since I screwed the darn thing up in the first place?
My questions would be and let me know if I am off base:
#1- Do you collimate using a star at night or some tool like a laser? (Because if they use a laser I have already done that and they are not as accurate as a star if you know how to do it.)
#2- Cost of course?
#3- If you don't collimate in the night sky how do I know it is done right?
Okay, I am through typing a rather long post for something I should have never had to write about in the first place!
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CPC 1100 XLT "The Big Monster"
Power Tank 17
NexImager
2" Smart Astronomy 10:1 dual speed Crayford focuser
2" Smart Astronomy Dielectric diagonal
2" Smart Astronomy 2x Barlow
2" Baader SCOPOS 35 mm prototype EP
Baader Hyperion zoom EP 8-24mm
Celestron dew shield
Bob's Knobs
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sanlopez
super member
Reged: 12/03/07
Posts: 149
Loc: 36 09'46.69 N, 86 46'38.26 W
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I'd ask to speak to the person doing the procedure, and ask them "what can I expect after I get it back?"
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Celestron GPS C925
Celestron Nexstar 5
2005 Gretsch SSLVO
Fender Custom Vibrolux
1963 Galaxie 500 XL convertible
1973 VW type 181 "The Thing"
And an absolutely wonderful wife
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rboe
Numbfinger
Reged: 03/16/02
Posts: 39739
Loc: Phx, AZ
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Centered is centered - sounds like your seeing is suffering. That can not be collimated.
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Ron
NS11GPS
Pronto
16" dob
15X70 Obies
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rboe
Numbfinger
Reged: 03/16/02
Posts: 39739
Loc: Phx, AZ
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To fine tune your collimation, switch to a fainter star and do the same thing. But also take note of twinkling, fuzzy tribble looking image and such. There are nights when two bands is the best I can do on Jupiter. Every once in a while it looks like a pasley shirt with all sorts of festoons and swirls - but you have to wait - too long - for those times. Early morning seems best for me in most cases.
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Ron
NS11GPS
Pronto
16" dob
15X70 Obies
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WNCAGC
sage
Reged: 06/25/08
Posts: 259
Loc: NC Mountains (God's country)
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Quote:
To fine tune your collimation, switch to a fainter star and do the same thing. But also take note of twinkling, fuzzy tribble looking image and such. There are nights when two bands is the best I can do on Jupiter. Every once in a while it looks like a pasley shirt with all sorts of festoons and swirls - but you have to wait - too long - for those times. Early morning seems best for me in most cases.
Good idea on the fainter stars. But I know it is still not exact like before since I use that same tree to gauge how well my focus is.
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CPC 1100 XLT "The Big Monster"
Power Tank 17
NexImager
2" Smart Astronomy 10:1 dual speed Crayford focuser
2" Smart Astronomy Dielectric diagonal
2" Smart Astronomy 2x Barlow
2" Baader SCOPOS 35 mm prototype EP
Baader Hyperion zoom EP 8-24mm
Celestron dew shield
Bob's Knobs
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rboe
Numbfinger
Reged: 03/16/02
Posts: 39739
Loc: Phx, AZ
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Could be heat waves are messing up your tree image. I use the big area lights over the freeway interchange at times and especially with the big dob poor collimation messes with the image quality.
As you move the focus from one side to the next you don't see a spike that moves out of the center do you?
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Ron
NS11GPS
Pronto
16" dob
15X70 Obies
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WNCAGC
sage
Reged: 06/25/08
Posts: 259
Loc: NC Mountains (God's country)
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Quote:
Could be heat waves are messing up your tree image. I use the big area lights over the freeway interchange at times and especially with the big dob poor collimation messes with the image quality.
As you move the focus from one side to the next you don't see a spike that moves out of the center do you?
No I don't. The weather yesterday evening when focusing in prior to dark was very mild and should have been no heat waves what so ever. I guess I will let the local camera store try a hand at it and ask what method they will use to do it.
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CPC 1100 XLT "The Big Monster"
Power Tank 17
NexImager
2" Smart Astronomy 10:1 dual speed Crayford focuser
2" Smart Astronomy Dielectric diagonal
2" Smart Astronomy 2x Barlow
2" Baader SCOPOS 35 mm prototype EP
Baader Hyperion zoom EP 8-24mm
Celestron dew shield
Bob's Knobs
Edited by WNCAGC (09/04/08 06:38 PM)
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Zoomster
professor emeritus
Reged: 01/30/05
Posts: 670
Loc: Tampa FL
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Sounds like you have completed the first step in collimation. Now you need to finish it. Use a bright star near zenith, focus as best you can, get it as sharp as possible, then study the shape of the star and look closely, you should see that it is slightly misshaped. Then tweak the knobs again but use the smallest movements possible, recenter the star if needed and check again, repeat until the image rocks!
Good Luck to ya'
Kurt
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Celestron CPC 1100 aka "The Marino"
Moonlite Dual Rate Focuser
WO Dielecric Diagonal
Denkmeier "Big Easy" Binos and assorted eyepieces.
Coranado PST
SPC900NC...not modded...yet. (eh-eh)
Is God willing to prevent evil, but not able? Then he is not omnipotent. Is he able, but not willing? Then he is malevolent. Is he both able and willing? Then whence cometh evil? Is he neither able nor willing? Then why call him God?
Epicurus
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Larry F
Pooh-Bah
Reged: 05/24/04
Posts: 1398
Loc: Westchester, NY
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You need to spend a good deal of time getting the collimation right and the screw tensions right (they have to be pretty tight, and maybe that's why you are slipping out when you think you've got it centered). An artificial star is the way to go. You can put the tube in a horizontal position and that makes it much easier to tweak the knobs and go back to the eyepiece until it's right. The tube isn't pointing up so you have a clear view of the screws. Just make sure you are using pretty high power at the end of the process (>400x if you can) and the artificial star is at least 75 feet away.
I recently saw an ad for an inexpensive ($18) version of an artificial star that uses a regular Mag-lite LED flashlight. The ad is here. The only problem with this is that the aperture is 200 microns, which may be too large. There are instructions all over the web of how to make one with aluminum foil or a coffee container, but the most important thing is to get the hole small (50 microns) and very round and the light very bright. That's why a commercially made one is the best, but expensive. There's a $110 self-contained unit made by Astrozap. Picostar is available in the UK. I use a Digitec, but they're out of business.
I don't think the SCT laser collimaters are as good as an artificial or natural star. They are very cumbersome to use. I was never successful with mine and sold it.
Do it slowly, methodically and optimistically. You'll get there. And you want to do it yourself because in the future you'll have to do it again!
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C5 Orange Tube SCT
Orion 127 Mak
SV Nighthawk (1st generation)
CPC 800 XLT SCT
Coronado Maxscope 40
5 1/4" f/5.2 home-built Newtonian
Denk II Binos
Giro 2/Tech2000 Giro Driver/Tech2000 QuickDraw Pier
A zillion eyepieces and some more mounts
Mason & Hamlin BB 214 cm (piano)
My Gallery
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Rusty
Postmaster
Reged: 08/06/03
Posts: 16408
Loc: Brooker, FL
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There are also tube currents - collimating before the tube interior has settled down is an exercise in frustration - but you can get it close.
And seeing conditions, day or night, can wreak havoc on the best efforts to collimate - or to see detail even when perfectly collimated. When I installed the Bob's Knobs on my N11, I used the Digi-tec (now discontinued) laser collimator, which was very accurate, but fiddly to use (actually, I worked with the designer with a production model and a prototype to try to make it more user-friendly. We succeeded in that, I think, and it was STILL fiddly, only slightly less so) It was 7 months before seeing settled down enough to tweak the scope to best star collimation.
Finally, seeing conditions restrict the power you can really use, even with a perfectly-collimated instrument. Rarely here in N. FL can I use more than 175-200X.
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N11GPS Fastar
TOA-130S
MK66 Std
Vintage C5
Megrez II 80mm ED Triplet APO
SolarMax 40
NJP Temma II
Sirius EQ-G
ST8XE/CFW-8(LRGBHa)/AO-7/DF-2/STV Dlx/ST237a/350D (Unmodded)/Mallincam Color Hyper Plus/DSI III Color/DSI II Pro
Two not-spoiled Golden Retrievers - Maggie and Casey
Sometimes I think we're alone in the universe, and sometimes I think we're not. In either case the idea is quite staggering. - Arthur C. Clarke
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rrenauc237
super member
Reged: 08/15/06
Posts: 190
Loc: Whitby, Ontario, Canada
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Quote:
As you move the focus from one side to the next you don't see a spike that moves out of the center do you?
What does this mean if you sometimes see a dark spike moving out from the center?? 
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Rick
CPC 9.25 XLT
7mmT6
12mmT4
19mm Panoptic
11, 15, 32mm Televue Plossl
2" WO dielectric diagonal
2x Barlow
Telrad
Whitby, Ontario
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bcuddihee
scholastic sledgehammer
Reged: 11/04/06
Posts: 935
Loc: Cincinnati Ohio
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A dark spike just means that your optics have not cooled down yet. It is a thermal rising off the secondary. No need for concern, it should go away.
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B Cuddihee
On the quest to find the best for the least!
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1968 Jason Empire 60X700mm refractor (my buddy from way back)
Celestron Nexstar8SE(a remarkable 8" grab and go)
Feathertouch Microfocuser
Stellarvue 50mm "Sparrowhawk" finder
Denk bino's with Power x switch
Pair of 26m Celestron Silvertop Plossls
Pair of Smart Astronomy 19 EF's
Pair of Smart Astronomy 16 EF's
Agena 38 SWA
Agena 26 SWA
Garrett 2" 2x ED Barlow
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rrenauc237
super member
Reged: 08/15/06
Posts: 190
Loc: Whitby, Ontario, Canada
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Thank you, I've only seen it a couple times.
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Rick
CPC 9.25 XLT
7mmT6
12mmT4
19mm Panoptic
11, 15, 32mm Televue Plossl
2" WO dielectric diagonal
2x Barlow
Telrad
Whitby, Ontario
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Stardaug
sage
Reged: 08/03/08
Posts: 210
Loc: Ontario, Canada
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I just took my first stab at collimation on my CPC800 last night. Used a jewelers screw driver and lots of care. Since I bought it I had suspicion that the collimation was slightly out. It wasn't as bad or scary as I thought it would be. I need to do a little more tweaking but the adjustments I did make helped quite a bit. I hope you are able to get your scope back to tip top shape soon. Good luck.
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Shawn / Ontario, Canada
Celestron CPC800 SCT w/XLT
Ball bearing mod on AZ
Skywatcher Equinox 80mm ED 500mm refractor
Canon Rebel XT 350D unmodded
ADM Counter weight system
and a Telrad!
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