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Equipment Discussions >> Reflectors

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Jon Isaacs
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Reged: 06/16/04

Loc: San Diego and Boulevard, CA
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: FirstSight]
      #5665127 - 02/06/13 12:21 PM

Quote:

THEREFORE, the only likely alternatives are:
a) let the matter rest, and live with periodically having to help folks misinformed by Andy's video clear up their misunderstandings as they climb the collimation learning curve;
OR b) one (or more of us in collaboration) get around tuit at some point to create a more accurate basic collimation instructional video with similar or better production values as Andy's.




Chris:

My personal approach will be:

- I will not provide links to Andy's Video when questions are asked about collimation.

- When someone else does provide that link, I will mention the errors in the video and provide a link to this thread.

Jon


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jgraham
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Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: FirstSight]
      #5665144 - 02/06/13 12:28 PM

"I do not believe there is a need for a new video. Andy's video is well known and well circulated but more importantly is a great video. All he needs to do is add an addendum to address the concern voiced in this thread."

That's a good approach. I'd would do it as a note since not all Newtonians have offset secondaries.


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Jason D
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Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: jgraham]
      #5665178 - 02/06/13 12:43 PM

Quote:

since not all Newtonians have offset secondaries



Many are under the impression if the secondary mirror is offsetted away from the focuser then the secondary silhouette shift will go away. This is incorrect. The secondary mirror silhouette shift will be seen even with scopes that included away-from-focuser offset.
Jason


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Chucky
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Reged: 04/16/10

Loc: Dublin, Ohio
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Jason D]
      #5665687 - 02/06/13 05:19 PM

Gosh, it must be very cloudy across most of the country right now.

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GeneT
Ely Kid
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Reged: 11/07/08

Loc: South Texas
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: FirstSight]
      #5665777 - 02/06/13 06:13 PM

Quote:

it's his right to do so.




No one disputes that. I just believe he could easily insert a small portion into his video and make some minor corrections or additions.


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rmollise
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Reged: 07/06/07

Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Chucky]
      #5665788 - 02/06/13 06:20 PM

Quote:

Gosh, it must be very cloudy across most of the country right now.




Must be...


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JohnMurphyRN
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Reged: 09/09/12

Loc: Near St Louis
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: David Pavlich]
      #5665790 - 02/06/13 06:21 PM

Quote:

It was my wording about the balowed laser. Again, put yourself in the beginner's living room. He has no clue about barlowed anything, let alone building one.






As a beginner a few months ago my first attempt at collimation was with a cat toy level laser centered by means of set screws inside a piece of PVC, barlowed. And this was all I was using until I got a HoTech a couple of months later. My barlowed cat toy was sufficient, and the results checked with the HoTech.


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Hothersale
sage


Reged: 10/13/09

Loc: Victoria, BC
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: JohnMurphyRN]
      #5665828 - 02/06/13 06:46 PM

If he hosted it on YouTube, I believe it would be trivial to overlay a few notes and small corrections using pop-up captions. I see other videos do this all the time.

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Heitman
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Reged: 01/26/07

Loc: Reeds, NC
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Hothersale]
      #5665866 - 02/06/13 07:13 PM

Poor ol' Andy.

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Starman1
Vendor (EyepiecesEtc.com)
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Reged: 06/24/03

Loc: Los Angeles
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: rmollise]
      #5665867 - 02/06/13 07:14 PM

Quote:

Quote:

"Those who get confused will eventually be shown the way in forums or by knowledgeable friends."

.....or walk away completely, never being able to get the scope to work right......and that is the real danger. But, I thank Andy for his in-depth video, luckily, I did some research before collimating my scope, so I knew the inconsistencies




Or just give up the whole kit-and-kaboodle after spending hours worrying about offsets and secondary shadows instead of looking at M42 or seeing anything besides a cotton-picking paper reinforcer donut.

Considerations such as these have a place, but not in Andy's nice beginner video, where they will confuse the issue to no good purpose.



Rod,
There is a big distance between a collimation treatise dealing with collimation tolerances calculations and the most basic of instructions.
IF one plans to do the latter, it behooves the author to at least be accurate, and the Andy's Shot Glass video is not.
I read nearly every thread on collimation posted in this and about 20 other forums, and I can tell you that that video has confused hundreds of people because they simply can't see what it says they should see.
The typical thread starts out: "I collimated my scope according to Andy's video but I just can't get everything concentric. If I adjust this, that goes out, etc. Help!"
When I'm instructing a rank beginner, I don't even mention centering the secondary under the focuser--I just talk about how to adjust the tilts of the two mirrors. Centering everything comes later.
And, I have illustrations of how things look through the peephole of the el cheapo combination tool so they can't get confused.
It's just as simple and easy to do it right as it is to do it wrong.
And a correct explanation or illustration, or image, would have eliminated hundreds of threads on forums.
The best solution, however, is to not refer people to the video. Unfortunately, it comes up high in the list when you ask Google about collimation.


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maakhand
professor emeritus
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Reged: 09/15/09

Loc: florida, usa
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Starman1]
      #5666114 - 02/06/13 10:02 PM

here is another newbie who agrees with the title of this thread. when i got my first telescope, an orion xt6 following the advice of an online buying guide( did not know about CN ) i was reasonably happy (ecstatic actually as i found ring nebula on third night ). but i never had pinpoint stars always with a little flare. after going through the included booklet i realized i did not do collimation. armed with the included collimation cap i spent some frustrating hours trying to have concentric circles as clearly illustrated by pictures in the booklet. even at f/8 it was clear i did not have the secondary properly positioned. i googled up collimation and found Andy's video. after watching it and trying once more i was positive i have a poorly made scope. i was cussing orion for selling a defective product, cussing myself for being a cheapskate for only spending $229. at one point i forcibly twisted and pushed the secondary holder hard to center it and something popped. lucky for me secondary collimation screws became loose.
as the flare was minimal and the secondary was miscollimated little bit only, i consoled myself by using the age old mantra 'you get what you pay for' and learned to live with it. in a month i found this forum and wow! . took me couple of more months to dare to venture down to reflector forum and find some threads on collimation written in greek . someone thanked Jason in one for an enlarged photo of his avatar and......
just my two cents.


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rmollise
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Reged: 07/06/07

Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Starman1]
      #5666710 - 02/07/13 09:37 AM

Quote:




Rod,
There is a big distance between a collimation treatise dealing with collimation tolerances calculations and the most basic of instructions.




Well, my opinion is that Andy's video is more than sufficient to get a beginner off the ground. But that's just my opinion, and you know what they say about "opinions."


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Tim Gilliland
professor emeritus


Reged: 03/28/09

Loc: Sand Springs Okla.
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: rmollise]
      #5666742 - 02/07/13 09:59 AM

Quote:

Quote:




Rod,
There is a big distance between a collimation treatise dealing with collimation tolerances calculations and the most basic of instructions.




Well, my opinion is that Andy's video is more than sufficient to get a beginner off the ground. But that's just my opinion, and you know what they say about "opinions."




I agree it is easily satisfactory for beginner's. I personnally started with it and felt comfortable at first. It is not perfect, with the way things change I doubt anything would be in a year or so. There is always a expert coming out with a new improved way to reach that perfect colimation and claiming if you don't do it this way you are not seeing anything. Funny thing is that when I started with a 4.5" reflector and was looking in awe at Jupiter before I had even heard of the term Collimation, I was happy. Was it better as I learned? (which by the way started with Andy's video's) yes it was. And I am still learning. My understanding took a recent leap. But I really don't see much change in performance. I just feel like I am more confident that I am doing it right.


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nevy
professor emeritus
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Reged: 02/07/12

Loc: UK
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: rmollise]
      #5666881 - 02/07/13 11:12 AM

Quote:

Quote:




Rod,
There is a big distance between a collimation treatise dealing with collimation tolerances calculations and the most basic of instructions.




Well, my opinion is that Andy's video is more than sufficient to get a beginner off the ground. But that's just my opinion, and you know what they say about "opinions."




As clint Eastwood once said “opinions are like {bleep} , everyone's got one”.

Edited by Jarad (02/07/13 05:44 PM)


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rmollise
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Reged: 07/06/07

Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: nevy]
      #5666910 - 02/07/13 11:31 AM

Quote:


As clint Eastwood once said “opinions are like {bleep} , everyone's got one”.




Which is what I was alluding to, but was too REFINED to say.

Edited by Jarad (02/07/13 05:45 PM)


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csrlice12
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Loc: Denver, CO
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: rmollise]
      #5666991 - 02/07/13 12:16 PM

Hey, a good bottle of Rebel Yell, and collimation just doesn't seem all that big a deal........

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GeneT
Ely Kid
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Reged: 11/07/08

Loc: South Texas
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: csrlice12]
      #5668065 - 02/07/13 11:05 PM

Quote:

Hey, a good bottle of Rebel Yell, and collimation just doesn't seem all that big a deal........




Two straight shots of Jameson will help set up all the concentric images into a perfect circle, or line, or whatever.


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jgraham
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Reged: 12/02/04

Loc: Miami Valley Astronomical Soci...
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: GeneT]
      #5668081 - 02/07/13 11:14 PM

"Gosh, it must be very cloudy across most of the country right now. "

No kidding. I think that a quality herbal tea is in order.


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droid
rocketman
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Reged: 08/29/04

Loc: Conneaut, Ohio
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: jgraham]
      #5668138 - 02/07/13 11:50 PM

Goodness people, people, honestly, lol

Its simple , someone create and maintain your own web site, create and develope your own video....and you can put in it anything under the sun you would like.

Whwn I first got in newtonians, I found web sites telling me I had to do off sets, and center the secondary by removing the spider and blah blah blah...and if you know what your doing and and comforatble with that level of detail, thats perfect....for you....not so much for me.
The first collimation video I found that was simple, didnt give me a head ache, and didnt require mw to take my scope apart...was Andys.
No it wasnt an advanced video, thankgoodness.
But it got me moving in the right direction.
Now after a couple years and hanging out with you collimation gurus, Im buying lazers, and collimating the collimater, thanks a lot guys,
Starting to come to grips with offset, still gives me a head ache though.


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johnnyha
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Reged: 11/12/06

Loc: Sherman Oaks, CA
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: GeneT]
      #5668337 - 02/08/13 04:36 AM

Quote:

Quote:

Hey, a good bottle of Rebel Yell, and collimation just doesn't seem all that big a deal........




Two straight shots of Jameson will help set up all the concentric images into a perfect circle, or line, or whatever.




I find Canadian Club gives me Concentric Circles.

Anyway, clearly, there was something in Andy's shot glass.


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