Return to the Cloudy Nights Telescope Reviews home pageAstronomics discounts for Cloudy Nights members
· Get a Cloudy Nights T-Shirt · Submit a Review / Article

Click here if you are having trouble logging into the forums

Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User

Equipment Discussions >> Reflectors

Pages: 1 | 2 | 3 | 4 | 5 | (show all)
FirstSight
Duke of Deneb
*****

Reged: 12/26/05

Loc: Raleigh, NC
Andy's Shot Glass Video - Wish He Would Correct It
      #5662493 - 02/04/13 09:13 PM

Andy's Shot Glass Collimation Video is a well-known web resource with wonderfully good intentions to help instruct new owners of newtonian reflectors how to go about collimating their scopes. The graphics are very clear, the explanations are very articulate and understandable, and it's very well-produced: in short, this would be, should be the kind of resource the astro community should be very grateful to have available to steer people to to learn the basics of collimation with elementary tools.

UNFORTUNATELY, it contains some items of egregiously incorrect information which undermine an otherwise solidly sound presentation. I know it takes a fair amount of effort to produce a good-quality, clearly understandable technical instruction video, but nevertheless the particular flaws in this presentation have been known for quite some time now, and I'm perplexed that Andy has so far apparently made no attempt to issue an updated, corrected version of his video.

Here's the main flaws:
1) He states that when the collimation process is successfully complete, all the reflections are lined up neatly concentric. This is not true of the innermost reflection of the secondary in the primary, which (in order to hit the optical rather than geometric center of the secondary mirror) is offset toward the focuser such that its outline will appear to rest tangent to the next circle out rather than concentrically centered within. This effect is *not* merely an artifact of using a fancy toolkit such as the Catseye Blackcat (cheshire) instead of a simple collimation cap; the effect is the same viewd through my Orion combo tool, which for purposes at hand is effectively nothing more than an improved version of a collimation cap. See, e.g. this picture from the Catseye website of how this proper offset looks, although in this case we are also seeing artifacts of using the BlackCat Cheshire, which does not however negate the essential point.
2) He states that the Orion Lasermate is "accurate", when the sub-premium 1.25" lasers in this class (and Orion's in particular) are notorious for themselves being significantly out-of-collimation right out of the box. So long as this miscollimation-of-laser isn't too severe, secondary mirror alighment is more forgiving than primary alighment in that so long as the secondary alignment still reflects the entire primary and isn't otherwise very severely off, the consequences from mild misalignment are merely slightly uneven illumination or loss of a few percentages of illumination efficiency...barely noticeable, if at all. And so, overlooking flaws in the laser beam's own alignment can be forgiven in the context of the secondary. NOT SO WITH RESPECT TO THE PRIMARY. The Orion Lasermate deluxe is equipped with a white screen projecting the return beam of the laser off the primary, with a hole in the middle of the screen which the user seeks to align the beam with. However, despite the superficial resemblance of this to e.g. the screen of a TuBlug in a barlowed laser setup, the Orion Lasermate is NOT a barlowed laser setup, but rather projects the direct image of the return beam itself, which even with an accurately collimated laser is NOT sufficiently accurate to insure reliable collimation of the primary mirror, especially in scopes whose f-ratios are closer to f/5 or below than f/6 (and Andy's XT10 scope shown in the video is f/4.7!!)
3) At the outset of the video, Andy states that the larger the scope, the more often it needs collimation, which is only accidentally, inconsistently sometimes so because the true relationship is that mis-collimation tolerance diminishes as the scope's focal-ratio grows shorter (and larger scopes often tend to be made with shorter focal-ratios than smaller scopes, but this isn't necessarily true, e.g the f/4.0 Orion Starblast 4.5".)

If I had a camera setup suitable for shooting a more accurate collimation video, this is something I'd love to undertake. Actually, not to put other folks up to tasks instead of doing work myself, but Jason and Don Pensack have each advanced vastly further in constructing accurate, well-illustrated tutorials than I have, and so have Vic Menard and Nils Olaf Cardin, but these all tend to be presented on a more sophisticated level better absorbed after a bit of experience with the equipment. No one has yet produced a good substitute for Andy's popular, but in too many important respects, misleading basic video for beginners. I wish Andy himself would undertake to correct his otherwise good video: he would richly deserve the praise and gratitude of the astro community if only he would do so.

Chris Mohr

Edited by FirstSight (02/05/13 08:43 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
ed_turco
Pooh-Bah
*****

Reged: 08/29/09

Loc: Lincoln, RI
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: FirstSight]
      #5662505 - 02/04/13 09:18 PM

If you weren't making short focus telescopes (f/4.5), this offset business wouldn't even trouble you. Perhaps Andy was speaking of f/6 or f/8 mirrors.

Why not write to him listing your concerns?


Post Extras: Print Post   Remind Me!   Notify Moderator  
FirstSight
Duke of Deneb
*****

Reged: 12/26/05

Loc: Raleigh, NC
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: ed_turco]
      #5662513 - 02/04/13 09:24 PM

Quote:

If you weren't making short focus telescopes (f/4.5), this offset business wouldn't even trouble you. Perhaps Andy was speaking of f/6 or f/8 mirrors.

Why not write to him listing your concerns?




I'm using CN as a sounding board to critique (and if necessary, correct) my analysis *before* trying to contact Andy. However, I'm far from the first person who's noticed these particular flaws in his presentation, and similarly it's unlikely I'd be the first person informing him of these concerns.

As you say, the purported inaccuracies probably have forgivably mild impact on f/8 scopes, but lots of relative beginners who access his video have sub-f/6 scopes e.g. lots of Zhummell scopes are f/5 for example. Also, these alleged errors are not at all necessary for clarity and simplification, but are each easily correctible without introducing needless complexity in the presentation.


Post Extras: Print Post   Remind Me!   Notify Moderator  
David PavlichAdministrator
Transmographied
*****

Reged: 05/18/05

Loc: Mandeville, LA USA
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: FirstSight]
      #5662598 - 02/04/13 10:16 PM

Andy's a pretty good guy. He would have probably been happy to discuss his tutorial with you. Is there a reason that you had to voice your opinion here first other than being a sounding board? I'm sure Andy would want to be made aware of his need for correction, so since I know Andy personally, I'll make him aware of your concerns.

David


Post Extras: Print Post   Remind Me!   Notify Moderator  
FirstSight
Duke of Deneb
*****

Reged: 12/26/05

Loc: Raleigh, NC
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: David Pavlich]
      #5662630 - 02/04/13 10:30 PM

Quote:

Andy's a pretty good guy. He would have probably been happy to discuss his tutorial with you. Is there a reason that you had to voice your opinion here first other than being a sounding board? I'm sure Andy would want to be made aware of his need for correction, so since I know Andy personally, I'll make him aware of your concerns.

David




Don't get me wrong, I think he deserves kudos for taking the effort to put together such a quality, well-articulated presentation but/for the small (but potentially important) handful of flaws I mentioned. Critiquing isn't the same as condemning. But why not run my own critique before a knowlegeable critical audience first, before contacting Andy? Seems like a good idea to me...especially since I don't dismiss the possibility that in some respects, I myself could be wrong or could stand correction or clarification.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jason D
Postmaster
*****

Reged: 10/21/06

Loc: California
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: FirstSight]
      #5662662 - 02/04/13 10:48 PM

In Chris's defense, many of us over the years pointed out that major error in the video's illustration that shows everything concentric.

Here is a 5 year old post -- one of many made by me and others
http://www.cloudynights.com/ubbthreads/showthreaded.php/Cat/0/Number/2144693/...

I do not know if Andy is still active in astronomy or if he would have the interest to edit his old video.

Jason


Post Extras: Print Post   Remind Me!   Notify Moderator  
GeneT
Ely Kid
*****

Reged: 11/07/08

Loc: South Texas
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: FirstSight]
      #5662675 - 02/04/13 11:03 PM

Maybe Andy can re-shoot and correct his original video.

Post Extras: Print Post   Remind Me!   Notify Moderator  
johnnyha
Postmaster
*****

Reged: 11/12/06

Loc: Sherman Oaks, CA
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: GeneT]
      #5662730 - 02/05/13 12:01 AM

Yes it's more a case of, how could he NOT know by now? The most egregious mistake is the concentric circles, this has been responsible for countless threads from people upset that their secondary shadow is not concentric even though they have done everything apparently right - and they have! The shadow should be offset towards the focuser. Because of this video it has to be repeated over and over and over.

Post Extras: Print Post   Remind Me!   Notify Moderator  
David PavlichAdministrator
Transmographied
*****

Reged: 05/18/05

Loc: Mandeville, LA USA
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: FirstSight]
      #5663089 - 02/05/13 08:58 AM

He got the message and video will remain. It's meant for a neophyte that wants to see stuff, not read a PhDs disertation and not spend a lot of money on barlowed lasers that cost more than their $250 Newt.

David


Post Extras: Print Post   Remind Me!   Notify Moderator  
FirstSight
Duke of Deneb
*****

Reged: 12/26/05

Loc: Raleigh, NC
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: David Pavlich]
      #5663164 - 02/05/13 09:40 AM

Quote:

He got the message and video will remain. It's meant for a neophyte that wants to see stuff, not read a PhDs disertation and not spend a lot of money on barlowed lasers that cost more than their $250 Newt.

David




The mistakes I critiqued aren't even remotely graduate-level material, but instead rather elementary, and potentially quite substantive errors that many folks will later need to un-learn to gain consistent collimation proficiency. They're not even justified as simplifications for the sake of introductory clarity for relative beginners, when accurate information would be just as clear and straightforward to present as inaccurate information.

BTW: the notion that a "barlowed" laser setup is a $250 investment is another needlessly (and wildly) inaccurate statement on his part, if that's what he said. First, anyone can easily convert an ordinary inexpensive barlow, e.g. the $30 Astro-Tech 2x barlow to a barlowed laser setup using little more than a piece of pierced white cardboard. Second, even the most elegant high-end prefab commercial barlowed setup, the Glatter TuBlug, is only $75 in 1.25" format.

Andy may indeed be generally a "pretty good guy" and I give him abundant positive credit points for taking the effort in the first place to create a well-produced collimation video for the benefit of the astro community. I could understand and respect his reluctance to do a corrected update to his video if his reply was along the lines: "yeah, it would be good to do that, but it took so many hours to create the existing version that it's difficult to find the time to re-do it." However, instead his response (at least as you report it) now comes across more as bullheaded stubborness and unwillingness to accept constructive criticism.

I should state what provoked my recent attention to this in the first place. Our local astronomy club periodically stages "telescope tune-up" clinics for neophyte non-members, which are regularly led by one of our members who has put together a really nice introductary general presentation of nuts and bolts of telescopes and observing which he presents at these events. However, he's primarily an SCT guy, and he's been using Andy's Shot Glass video at these presentations for the reflector folks in the audience. I've pointed out the flaws in this video to him, but unfortunately it's also true that there's not really an alternative good basic instruction video available (yet, anyway). At these clinics, I sometimes find myself explaining to newbies why the innermost reflection isn't concentric after I've finished helping them collimate their reflector, contrary to Andy's video. And so, I didn't just tee this subject up randomly in order to be a smarty-mouth curmudgeon, but because it's sowed actual confusion I've had to try to clear up.

Also David, why didn't you wait and let me attempt to contact him after I had vetted my critique here to insure its accuracy before approaching him? I get the impression that the cup is now a bit poisoned for me to attempt a diplomatic approach to him, regardless of whatever manner you may have communicated it to him first.

Edited by FirstSight (02/05/13 09:53 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
rmollise
Postmaster
*****

Reged: 07/06/07

Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: FirstSight]
      #5663218 - 02/05/13 10:00 AM

1. Some folks offset their secondaries. Some don't. Not critical IMHO, and certainly not necessary for longer scopes. Also, it is just confusing for novices who much of Andy's excellent material is aimed at.

2. Orion's widget can produce a good collimation. I know because I have used it for field collimation clinics at star parties. I still prefer my good old combo Cheshire/sight tube, but plenty of folks would consider it SUB PREMIUM, too. A beginner most assuredly doesn't need to go all OCD on collimation and spend for barlowed 400 buck gadgets. That is the kind of stuff that just bogs 'em down for no good reason.

3. I don't find the StarBlast needs collimation frequently at all if it is done right in the first place and locked down. In general larger scopes _do_ require more frequent collimation. That's the penalty for larger, heavier primaries in lighter truss tube bodies.

My verdict on Andy's Shotglass? Extremely well done and valuable for novices.

Edited by rmollise (02/05/13 01:05 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
FirstSight
Duke of Deneb
*****

Reged: 12/26/05

Loc: Raleigh, NC
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: rmollise]
      #5663268 - 02/05/13 10:22 AM

Quote:


2. Orion's widget can produce a good collimation. I know because I have used it for field collimation clinics at star parties.




I still have my Orion widget, even though I don't use it any more for my own scopes because I also now have the Catseye and Glatter tools. I keep it especially for use at telescope tune-up clinics or any other setting where the person I'm helping owns similar tools. I even still have my Orion 1.25" laser, which is useful when helping folks with similar tools or whose focuser is only 1.25" since my Glatter is 2" only - but it's nevertheless a good idea to teach others what the flaws of the Orion laser are, and when and how to they need to work around these flaws to make it a still-useful tool.

If the matters I mentioned were just graduate-level theoretical stuff which was nevertheless always inconsequential in practice, there would be no reason to stir the pot over Andy's presentation as-is. If accurate clarity was difficult to achieve in a basic presentation without indulging some potentially problematic simplifications, likewise there would be inadequate reason to stir the pot.

However, I'll just have to respectfully disagree with you on this Uncle Rod. I mean no disrespect to the service Andy has tried to bring to the astro community with the tremendous effort that obviously went into creating his presentation. However, that fact does not immunize his work from valid constructive criticism.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jason D
Postmaster
*****

Reged: 10/21/06

Loc: California
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: David Pavlich]
      #5663275 - 02/05/13 10:23 AM

Quote:

He got the message and video will remain. It's meant for a neophyte that wants to see stuff, not read a PhDs disertation and not spend a lot of money on barlowed lasers that cost more than their $250 Newt.

David




David, I believe Andy got the message years ago and the fact the video remained shows that he decided long time ago not to change it.
Your response is little harsh. Those who get confused by his video and by most scope manuals that show perfectly concentric circles do not seek PhD level knowledge. I for one was very confused with the shift of the secondary mirror silhouette when I started on this hobby.
Having said the above, I do not believe Andy is obligated to change his video. If he does not want to change it, that is OK. Those who get confused will eventually be shown the way in forums or by knowledgeable friends.
Jason


Post Extras: Print Post   Remind Me!   Notify Moderator  
rmollise
Postmaster
*****

Reged: 07/06/07

Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: FirstSight]
      #5663293 - 02/05/13 10:29 AM

You're free to criticize him, I'm free to criticize him. That's not the point. The point is that his pages are clearly aimed at beginners, and that the things you find disturbing will really be of no consequence for them.

Me? I ain't that sophisticated, I guess, but I would much rather a novice collimate with a dadgum collimation cap and start looking at and enjoying the sky than begin obsessing over offsets and other things that will, frankly, have an extremely minor effect on images in any telescope.

I have no doubt that your criticisms come from the heart, and that you think these things are important and want to spread the word. And for some venues they indeed might be. For Andy's starry-eyed beginner, though, I'd have to say "not so much." For them, simple, or even "quick and dirty" is better. Something I've learned from my own missteps with novice amateurs and my university astronomy students over too many years.


Post Extras: Print Post   Remind Me!   Notify Moderator  
FirstSight
Duke of Deneb
*****

Reged: 12/26/05

Loc: Raleigh, NC
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Jason D]
      #5663300 - 02/05/13 10:34 AM

Quote:

Quote:

He got the message and video will remain. It's meant for a neophyte that wants to see stuff, not read a PhDs disertation and not spend a lot of money on barlowed lasers that cost more than their $250 Newt.

David




David, I believe Andy got the message years ago and the fact the video remained shows that he decided long time ago not to change it.
Your response is little harsh. Those who get confused by his video and by most scope manuals that show perfectly concentric circles do not seek PhD level knowledge. I for one was very confused with the shift of the secondary mirror silhouette when I started on this hobby.
Having said the above, I do not believe Andy is obligated to change his video. If he does not want to change it, that is OK. Those who get confused will eventually be shown the way in forums or by knowledgeable friends.
Jason




Since Andy is apparently unwilling to update his video, the alternative is to either live with it and hope most people eventually grow out of any early misimpressions they get from this otherwise good aid, or else...take the trouble to create an alternative video for the web. As fable of the hen making bread goes, unless and until I'm willing and able to help make bread on this (and not expect e.g. Jason or Vic etc. to do it for me)...I'll just have to live with helping newbies one-on-one with gaining accurate understanding whenever they're confused by any oversimplifications or inaccuracies about collimation. Perhaps this would be a worthwhile project to undertake, but it's just words of good, but empty intentions unless and until I actually got going on it.


Post Extras: Print Post   Remind Me!   Notify Moderator  
David PavlichAdministrator
Transmographied
*****

Reged: 05/18/05

Loc: Mandeville, LA USA
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: FirstSight]
      #5663389 - 02/05/13 11:17 AM

Lose your present knowledge and you're in your living room with your new XT8 with your collimation cap and you want to get out and see stuff. You look at the directions and read:

" This is not true of the innermost reflection of the secondary in the primary, which (in order to hit the optical rather than geometric center of the secondary mirror) is offset toward the focuser such that its outline will appear to rest tangent to the next circle out rather than concentrically centered within."

I know exactly what you mean, but what do you think the beginner sitting in his living room is now thinking? Was I a bit harsh? Perhaps, however, unless this beginner is an optical engineer or a Physics major, the above just sent the beginner into a tailspin.

The natural progression is to get the scope out, clean up the collimation as best he can with his cap, see things and then ask questions. Andy's video will improve the cap results. Then he can dig deeper and find ways to refine what he's seeing.

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.

I'll leave it at the fact that Andy's video is a help to simplify things for a beginner which is how it was intended. When the beginner gets a bit more knowledgeable, he can dive into the nuances of collimation.

David


Post Extras: Print Post   Remind Me!   Notify Moderator  
csa/montana
Den Mama
*****

Reged: 05/14/05

Loc: montana
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: rmollise]
      #5663406 - 02/05/13 11:27 AM

Quote:

My verdict on Andy's Shotglass? Extremely well done and valuable for novices.




Agreed; this video was a great help to me in understanding the mystery of collimating, when I first started with my 8" dob. I was hopelessly confused. This video gave me the basis of collimating to go on & enjoy astronomy. Was it precise & 100% correct? I didn't know or care, as after applying his instructions, I actually could see something with my scope!

As I gained knowledge (from these forums), I refined my collimating further, with better tools; I don't feel the video stunted my understanding of how to properly collimate at all, rather got me on my way to a very enjoyable life of viewing.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Nils Olof Carlin
Carpal Tunnel
*****

Reged: 07/26/04

Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: David Pavlich]
      #5663432 - 02/05/13 11:38 AM

I can only agree with Chris' very constructive criticism of the video.
As Chris writes, and Johnny reinforces, and Jason and others have pointed out since long ago:
showing and claiming that all "lines up so nicely" will indeed confuse (and has indeed confused) many a the beginner, trying in vain and in desperation to make things concentric. Does anyone think a correct statement here would really make things more confusing than that?

All that is needed is a short comment that the reflection of the collimating cap and the dark shadow of the secondary may not appear quite concentric even if everything else is, and need not be - it's all right that they are not. This is not PhD stuff, but it is basic telescope optics, and David, there is no need at all to bring up offset in the context.

Less critical:
The illustrations show a frame of black around the optics, with a distinct circular opening in which you center the secondary. This, I think, poorly represents reality, where the focuser drawtube may be much too short and wide to reliably make the secondary "centered in the whole view" (cf. the diagram in the beginning of the video).
Inexact centering will make the focuser axis off, more or less - then again, maybe the beginner really does not need to worry about the focuser axis (cf. Gary Seronik's collimation article in S&T last sept.).

In the process of adjusting the primary, Andy says: "I see the reflection of my eye down there". The beginner might take this to mean that the collimating cap is removed at this stage, which it should not be. You can't then literally see your eye - without the centered peephole, you can not center your eye in the focuser to a meaningful accuracy.

Also, even if the laser collimation is done, it would be prudent to check the primary's adjustment with the collimation cap - easily done to get the best precision that simple collimation can get.

David wrote: "He got the message and video will remain." ??
All the more reason for somebody skilled with video to make something better suited to the needs of the beginner. I am not aware that any of the many collimation videos on Youtube qualifies (I am sure I have not seen them all).

"Everything should be made as simple as possible, but not simpler."

Nils Olof


Post Extras: Print Post   Remind Me!   Notify Moderator  
ed_turco
Pooh-Bah
*****

Reged: 08/29/09

Loc: Lincoln, RI
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: csa/montana]
      #5663451 - 02/05/13 11:50 AM

Gee, after all this discussion and dissertating , all I've used on my f/6s and longer is a thread spool, which came in 1.25" diameter and has a 6mm hole in it. And it was free.

Never had a worry about collimation.

Ed


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jason D
Postmaster
*****

Reged: 10/21/06

Loc: California
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: David Pavlich]
      #5663474 - 02/05/13 12:05 PM Attachment (23 downloads)

Quote:

" This is not true of the innermost reflection of the secondary in the primary, which (in order to hit the optical rather than geometric center of the secondary mirror) is offset toward the focuser such that its outline will appear to rest tangent to the next circle out rather than concentrically centered within."




How about:

"Refer to the attached illustration. It represents what you will see through the collimation cap for a well collimated scope. Note: Ignore the spider vanes reflection position and the secondary shadow indicated by the arrows. These might look out of alignment"


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jason D
Postmaster
*****

Reged: 10/21/06

Loc: California
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Jason D]
      #5663498 - 02/05/13 12:18 PM

Even better, why can't the video and scope manuals include a real picture of what is expected to be seen via the collimation cap for a well-collimated scope. Something similar to the attachment.



Post Extras: Print Post   Remind Me!   Notify Moderator  
David PavlichAdministrator
Transmographied
*****

Reged: 05/18/05

Loc: Mandeville, LA USA
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Jason D]
      #5663573 - 02/05/13 01:11 PM

Jason, I have no beef with you or anyone else's capability. After I learned the basics, I dug around and found the sites that show how to fine tune a Newt. All Andy did was make a video that simplifies what some consider a black art when they enter the world of Newtonians.

I would suggest that someone produce an Advanced Collimation Video and post it. There's enough people here with the expertise to do it. Include all the proper tools and how they work as well. It's like processing a CCD image. Tony Hallas can take my data and make it look like a Hubble image. But guess what....Tony didn't do that when he had his first images sitting in Photoshop. It took him a lot of time and effort to get to the top in his field.

At any rate, I'll leave it there. I don't want to give my fellow moderators a headache.

David


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jason D
Postmaster
*****

Reged: 10/21/06

Loc: California
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: David Pavlich]
      #5663610 - 02/05/13 01:46 PM

I believe you are reading too much into our posts. I believe the general theme of replies is that Andy's video is good and it could be better with a minor update.
Jason


Post Extras: Print Post   Remind Me!   Notify Moderator  
FirstSight
Duke of Deneb
*****

Reged: 12/26/05

Loc: Raleigh, NC
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Jason D]
      #5663617 - 02/05/13 01:55 PM

Quote:

I believe you are reading too much into our posts. I believe the general theme of replies is that Andy's video is good and it could be better with a minor update.
Jason




Exactly. The proposed corrections under discussion do not require introducing anything at all difficult to correctly explain or present, nor to understand by a neophyte. They do, however require someone, whether by way of Andy himself or someone creating an alternative basic collimation tutorial video, to apply the necessary time and effort, which may not be quite so trivial an undertaking.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Nils Olof Carlin
Carpal Tunnel
*****

Reged: 07/26/04

Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: David Pavlich]
      #5663630 - 02/05/13 02:02 PM

Quote:

I would suggest that someone produce an Advanced Collimation Video and post it.


So far, this thread has been about wanting a basic collimation video, much like like Andy's, with the confusing and potentially misleading parts (look back the thread to see them specified) corrected - not more complex, just more right. If Andy is satisfied leaving his own video as is (see the title of this thread), our hope goes to someone else. We are a couple here who know collimation at any desired level (some can make not only beautiful but also correct illustrations!) - but who is good at video making?

Nils Olof


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jon Isaacs
Postmaster
*****

Reged: 06/16/04

Loc: San Diego and Boulevard, CA
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Nils Olof Carlin]
      #5663776 - 02/05/13 03:26 PM

Quote:

So far, this thread has been about wanting a basic collimation video, much like like Andy's, with the confusing and potentially misleading parts




Nils:

I believe you wanted to say "without the confusing and potentially misleading parts."

In any event, it would seem that if the video were not changed, at least a note could be included to point out the possible errors, the possible sources of confusion. An incorrect representation has the possibility of confusing a perceptive beginner.

Jon


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jason D
Postmaster
*****

Reged: 10/21/06

Loc: California
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Jon Isaacs]
      #5663839 - 02/05/13 04:00 PM

Quote:

In any event, it would seem that if the video were not changed, at least a note could be included to point out the possible errors, the possible sources of confusion. An incorrect representation has the possibility of confusing a perceptive beginner.

Jon




Good point, Jon.

Andy could include an addendum to the same web page as the video with an illustration and a message similar to what I included in my earlier reply

http://www.cloudynights.com/ubbthreads/showthreaded.php/Cat/0/Number/5663474/...

Andy is welcome to use the illustration I added to the above reply.

Jason


Post Extras: Print Post   Remind Me!   Notify Moderator  
Nils Olof Carlin
Carpal Tunnel
*****

Reged: 07/26/04

Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Jon Isaacs]
      #5663850 - 02/05/13 04:04 PM

Hi Jon,

what I tried to say was:
"...with the confusing and potentially misleading parts(...) corrected.

Edited by Nils Olof Carlin (02/05/13 04:04 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
csrlice12
Postmaster
*****

Reged: 05/22/12

Loc: Denver, CO
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Jason D]
      #5663954 - 02/05/13 05:04 PM

"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


Post Extras: Print Post   Remind Me!   Notify Moderator  
rmollise
Postmaster
*****

Reged: 07/06/07

Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: csrlice12]
      #5664011 - 02/05/13 05:29 PM

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.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jon Isaacs
Postmaster
*****

Reged: 06/16/04

Loc: San Diego and Boulevard, CA
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: rmollise]
      #5664141 - 02/05/13 06:39 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.




A beginners video need not necessarily address the fine points but the illustrations and examples should be accurate so that a perceptive beginner is not mislead into thinking something is wrong when it is A-OK.

Jon


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jason D
Postmaster
*****

Reged: 10/21/06

Loc: California
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: rmollise]
      #5664142 - 02/05/13 06:39 PM

Quote:

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.




Isn't that what most replies in this thread are going after?
When beginners see a shifted secondary shadow via their collimation cap which does not match what is shown in manuals and videos they get stuck. Instead of going out to see M42, they spend more frustrating time trying to figure out what they did incorrectly!!! After all, a shifted secondary shadow is intuitively seen as an error.
Many of us are try to help beginners by informing them that spider vanes and secondary shadows could look misaligned and they should stop worrying about them and go out to observe M42.
Jason


Post Extras: Print Post   Remind Me!   Notify Moderator  
beatlejuice
Pooh-Bah
*****

Reged: 04/05/11

Loc: Hamilton, ON,Canada
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Jason D]
      #5664191 - 02/05/13 07:14 PM

Quote:

When beginners see a shifted secondary shadow via their collimation cap which does not match what is shown in manuals and videos they get stuck. Instead of going out to see M42, they spend more frustrating time trying to figure out what they did incorrectly!!!




That is exactly what happend to me when I purchased my first reflector about 12 years ago. The XT10 came with collimation instructions that showed everything perfectly centered. It was definitely a head scratcher for me until I phoned Orion and there was actually someone there who was able to set me straight.

Eric


Post Extras: Print Post   Remind Me!   Notify Moderator  
Ed D
Carpal Tunnel
*****

Reged: 04/30/10

Loc: Sunny South Florida
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: beatlejuice]
      #5664241 - 02/05/13 07:50 PM

Are there any other collimation videos out there that address the shortcomings in Andy's video that we can recommend to novices?

Ed D


Post Extras: Print Post   Remind Me!   Notify Moderator  
beatlejuice
Pooh-Bah
*****

Reged: 04/05/11

Loc: Hamilton, ON,Canada
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Ed D]
      #5664346 - 02/05/13 09:27 PM

I dont know about videos but these are the sites that I found most useful when it seemed like I was on my own.

Collimating newtonian optics
and
John Reed's Home Page Collimation

Eric


Post Extras: Print Post   Remind Me!   Notify Moderator  
GeneT
Ely Kid
*****

Reged: 11/07/08

Loc: South Texas
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Nils Olof Carlin]
      #5664367 - 02/05/13 09:41 PM

Quote:

what I tried to say was:
"...with the confusing and potentially misleading parts(...) corrected.




This is reasonable. Come on Andy--you made a great collimation video. But, why not re-shoot a small portion, edit it in, and make your video even better?


Post Extras: Print Post   Remind Me!   Notify Moderator  
Scanning4Comets
Markus
*****

Reged: 12/26/04

Loc: Ontario, Canada
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: GeneT]
      #5664437 - 02/05/13 10:31 PM

I agree that the video needs updating or addressed.

Cheers,


Post Extras: Print Post   Remind Me!   Notify Moderator  
csrlice12
Postmaster
*****

Reged: 05/22/12

Loc: Denver, CO
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Scanning4Comets]
      #5664830 - 02/06/13 09:06 AM

I've got a Glatter/TuBlug and the collimating eyepiece that came with the refractor and a collimating cap, and a couple of scopes. Anyone in Denver who's knowledgeable in collimating (not me, don't know enough of the techie stuff); and has access to a video camera is welcome to meet me some time and can use my equipment to film a video. It would really be nice to have a series of videos showing how to collimate with a Cheshire/Catseye/Glatter/Barlow, etc... I'll even hold the camera.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Jason D
Postmaster
*****

Reged: 10/21/06

Loc: California
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: csrlice12]
      #5664864 - 02/06/13 09:31 AM

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.

Post Extras: Print Post   Remind Me!   Notify Moderator  
FirstSight
Duke of Deneb
*****

Reged: 12/26/05

Loc: Raleigh, NC
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Jason D]
      #5665039 - 02/06/13 11:31 AM

Quote:

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.




Except apparently Andy indicates he's not at all inclined to do that. So says his buddy CN member David Pavlich. Further, although a clear majority of respondents to this thread indicate agreement that an update to fix the inaccuracies should be done, there is a substantial minority supporting Andy in leaving the video as is, thereby encouraging Andy to stay put with his disinclination. So be it, it's his right to do so.

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.

I'm not hereby saying any particular one(s) among us necessarily has any obligation to take on option b). To do something like that worthwhile well will probably be a more nontrivial, time-consuming project that it may seem in the abstract. But that would be a good thing if someone's able and willing to take it on.

Edited by FirstSight (02/06/13 11:57 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jon Isaacs
Postmaster
*****

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


Post Extras: Print Post   Remind Me!   Notify Moderator  
jgraham
Postmaster
*****

Reged: 12/02/04

Loc: Miami Valley Astronomical Soci...
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.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jason D
Postmaster
*****

Reged: 10/21/06

Loc: California
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


Post Extras: Print Post   Remind Me!   Notify Moderator  
Chucky
sage
*****

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.

Post Extras: Print Post   Remind Me!   Notify Moderator  
GeneT
Ely Kid
*****

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.


Post Extras: Print Post   Remind Me!   Notify Moderator  
rmollise
Postmaster
*****

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...


Post Extras: Print Post   Remind Me!   Notify Moderator  
JohnMurphyRN
sage
*****

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.


Post Extras: Print Post   Remind Me!   Notify Moderator  
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.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Heitman
sage
*****

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.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Starman1
Vendor (EyepiecesEtc.com)
*****

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.


Post Extras: Print Post   Remind Me!   Notify Moderator  
maakhand
professor emeritus
*****

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.


Post Extras: Print Post   Remind Me!   Notify Moderator  
rmollise
Postmaster
*****

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."


Post Extras: Print Post   Remind Me!   Notify Moderator  
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.


Post Extras: Print Post   Remind Me!   Notify Moderator  
nevy
professor emeritus
*****

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)


Post Extras: Print Post   Remind Me!   Notify Moderator  
rmollise
Postmaster
*****

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)


Post Extras: Print Post   Remind Me!   Notify Moderator  
csrlice12
Postmaster
*****

Reged: 05/22/12

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........

Post Extras: Print Post   Remind Me!   Notify Moderator  
GeneT
Ely Kid
*****

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.


Post Extras: Print Post   Remind Me!   Notify Moderator  
jgraham
Postmaster
*****

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.


Post Extras: Print Post   Remind Me!   Notify Moderator  
droid
rocketman
*****

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.


Post Extras: Print Post   Remind Me!   Notify Moderator  
johnnyha
Postmaster
*****

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.


Post Extras: Print Post   Remind Me!   Notify Moderator  
droid
rocketman
*****

Reged: 08/29/04

Loc: Conneaut, Ohio
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: johnnyha]
      #5668443 - 02/08/13 08:10 AM

Still working on getting someone whos traveling south, to bring me back a bottle of rebel yell.

I find Jack daniels makes any telescope work like the hubble, rivers on the moon and all


Post Extras: Print Post   Remind Me!   Notify Moderator  
csrlice12
Postmaster
*****

Reged: 05/22/12

Loc: Denver, CO
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: droid]
      #5668560 - 02/08/13 09:23 AM

Don't foget to take off the mouthcap first!

Post Extras: Print Post   Remind Me!   Notify Moderator  
jrbarnett
Eyepiece Hooligan
*****

Reged: 02/28/06

Loc: Petaluma, CA
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: ed_turco]
      #5669906 - 02/08/13 10:32 PM

Andy's Newtonian was a 10" f/4.7, so fast enough that proper textbook collimation would call for offset that whould be noticeable, but...

Honestly, if you collimate even an f/4.5 exactly as he suggests, with no offset, you probably won't notice the difference visually 9 nights out of 10 in the west and 99 nights out of 100 in the east.

Regards,

Jim


Post Extras: Print Post   Remind Me!   Notify Moderator  
Starman1
Vendor (EyepiecesEtc.com)
*****

Reged: 06/24/03

Loc: Los Angeles
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: jrbarnett]
      #5670021 - 02/09/13 12:55 AM

Quote:

Andy's Newtonian was a 10" f/4.7, so fast enough that proper textbook collimation would call for offset that would be noticeable, but...

Honestly, if you collimate even an f/4.5 exactly as he suggests, with no offset, you probably won't notice the difference visually 9 nights out of 10 in the west and 99 nights out of 100 in the east.

Regards,

Jim



Jim,
If you center the secondary in the tube and under the focuser, the process of collimation tilts the optical axis slightly towards the focuser. This is often referred to as the "New Model" of collimation. The result is actually full offset for the secondary and the angle of intersection at the secondary is slightly more than 90 degrees. You see the same off-center shadow of the secondary you would were the secondary mirror offset in the tube and the optical axis coincident with the center line of the OTA.
The point is, you cannot achieve a complete concentricity to all images and be collimated. THAT'S what is wrong with the video.


Post Extras: Print Post   Remind Me!   Notify Moderator  
johnnyha
Postmaster
*****

Reged: 11/12/06

Loc: Sherman Oaks, CA
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Starman1]
      #5670035 - 02/09/13 01:26 AM

Quote:

The point is, you cannot achieve a complete concentricity to all images and be collimated. THAT'S what is wrong with the video.




Perfectly spoken.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Nils Olof Carlin
Carpal Tunnel
*****

Reged: 07/26/04

Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: jrbarnett]
      #5670126 - 02/09/13 04:11 AM

Quote:

Andy's Newtonian was a 10" f/4.7, so fast enough that proper textbook collimation would call for offset that whould be noticeable, but...




Maybe "offset" could be better understood than it usually is now.

Think of the position of the fully illuminated field:
You would want it (at least reasonably) centered in the focuser. This is perhaps easiest acheved by centering the secondary using a suitable sight tube (for want of one, you could, usually with poor precision, use the focuser drawtube). If you do, the shadow of the secondary reflected in the primary, will necessarily be decentered relative to the reflection of the focuser and the cheshire, collimation cap etc. The decentering depends on the focal ratio, but how obvious it is depends, I think, more on the relative size of the focuser and the secondary - if they are fairly close, as in smaller instruments, the more obvious it is.
And that is of course the heart of the subject at hand - a few of the posters apparently have never noticed, others have. Beginners trying to learn collimation can, as we know, be utterly confused by the fact that they fail to get everything concentric as some unsuitable video or manual will say. (They probably do not try the non-obvious trick to center the reflections of the secondary and focuser - you move the secondary away from the primary. This, of course, makes the secondary (not reflected) be displaced, very obvious in a sight tube, less so without one. Also not so obvious is that the fully illuminated field is shifted in the same direction, the negative aspect particularly in beginner size instruments.)

Don't think offset - think optical centering of the secondary, and do it simply with a sight tube (easily made!).
But most of all, avoid instructions that suggest that everything seen in the peephole will be nicely centered. It simply can't be done!

Nils Olof


Post Extras: Print Post   Remind Me!   Notify Moderator  
rmollise
Postmaster
*****

Reged: 07/06/07

Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Starman1]
      #5670286 - 02/09/13 08:27 AM

Quote:


Jim,
If you center the secondary in the tube and under the focuser, the process of collimation tilts the optical axis slightly towards the focuser. This is often referred to as the "New Model" of collimation. The result is actually full offset for the secondary and the angle of intersection at the secondary is slightly more than 90 degrees. You see the same off-center shadow of the secondary you would were the secondary mirror offset in the tube and the optical axis coincident with the center line of the OTA.
The point is, you cannot achieve a complete concentricity to all images and be collimated. THAT'S what is wrong with the video.




But the other point is, a beginner can collimate using the easy instructions on Andy's video and get excellent images. Images indistinguishable from someone whose umptysquats and thises and thats are CONCENTRIC!


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jason D
Postmaster
*****

Reged: 10/21/06

Loc: California
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: rmollise]
      #5670402 - 02/09/13 09:51 AM

Quote:

But the other point is, a beginner can collimate using the easy instructions on Andy's video and get excellent images



I believe you are still missing the point of this thread. This thread is not about "offsets" or about getting soft views at the eyepiece. This thread is about many beginners getting confused and frustrated following Andy’s video because their actual collimation cap view shows non-concentric circles unlike the illustrations used in the video.
Jason


Post Extras: Print Post   Remind Me!   Notify Moderator  
FirstSight
Duke of Deneb
*****

Reged: 12/26/05

Loc: Raleigh, NC
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: rmollise]
      #5670459 - 02/09/13 10:26 AM

Quote:

Quote:


Jim,
If you center the secondary in the tube and under the focuser, the process of collimation tilts the optical axis slightly towards the focuser. This is often referred to as the "New Model" of collimation. The result is actually full offset for the secondary and the angle of intersection at the secondary is slightly more than 90 degrees. You see the same off-center shadow of the secondary you would were the secondary mirror offset in the tube and the optical axis coincident with the center line of the OTA.
The point is, you cannot achieve a complete concentricity to all images and be collimated. THAT'S what is wrong with the video.




But the other point is, a beginner can collimate using the easy instructions on Andy's video and get excellent images. Images indistinguishable from someone whose umptysquats and thises and thats are CONCENTRIC!




SO: What exactly would one need to physically do during initial setup of the secondary/primary and the collimation process to be able to get the perfectly concentric end-result shown in Andy's video? Under what circumstances would following the steps indicated in his video in fact lead to perfectly concentric results (are there any unstated assumptions necessary to make it work?). Corollary question: under what circumstances would this result in a well-collimated vs miscollimated scope? (As distinguised from say, a result which produces, especially in slower focal-ratio scopes or at lower magnifications, a plausibly-enough viewable image that is nonetheless not an optimally tuned one?)

One common set of circumstances where it will assuredly NOT result in neat concentricity is if the secondary is first centered under the focuser with a sight tube. The reason why has been explained in several posts above.

Edited by FirstSight (02/09/13 11:02 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Starman1
Vendor (EyepiecesEtc.com)
*****

Reged: 06/24/03

Loc: Los Angeles
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: rmollise]
      #5670519 - 02/09/13 11:09 AM

Quote:

Quote:


Jim,
If you center the secondary in the tube and under the focuser, the process of collimation tilts the optical axis slightly towards the focuser. This is often referred to as the "New Model" of collimation. The result is actually full offset for the secondary and the angle of intersection at the secondary is slightly more than 90 degrees. You see the same off-center shadow of the secondary you would were the secondary mirror offset in the tube and the optical axis coincident with the center line of the OTA.
The point is, you cannot achieve a complete concentricity to all images and be collimated. THAT'S what is wrong with the video.




But the other point is, a beginner can collimate using the easy instructions on Andy's video and get excellent images. Images indistinguishable from someone whose umptysquats and thises and thats are CONCENTRIC!



Actually, my earlier statement was poorly stated. It should have read:
"The point is, you cannot achieve a complete concentricity to all images. The process of collimation guarantees they won't be. THAT'S what is wrong with the video.



And judging by the number of threads that start out with confusion over that fact, the number of videos and books with inaccurate information must be large.
Look, align the mirror tilts ignoring concentricities and secondary mirror placement and you will be collimated and have fun with the scope. It's simple. Even if the field is not perfectly illuminated or the focal plane is even slightly tilted. But the video doesn't tell people to ignore that, and the images shown are misleading.


Post Extras: Print Post   Remind Me!   Notify Moderator  
astro_baby
scholastic sledgehammer


Reged: 06/17/08

Loc: United Kingdom
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Starman1]
      #5670727 - 02/09/13 01:11 PM

When I came back into this hobby from an age when there were no fast scopes I did use Andys video and I did in fact find it misleading as it showed a concentric pattern that was impossible to achieve with my F5. LOTS of other guides online showed the same thing and this created confusion to my brain...

After much pulling of hair out, wailing and gnashing of teeth I finally got it sorted about offset largely through a thread on here and some PM to/from Jason.

The result was me building a collimation guide which I hoped would find a mid point between high end collimation guides and the overly basic ones but which would cover off all of the issues.

The guide gets a lot of use judging from page stats on my site but I too have taken stick from people about some areas of it.

The fact is you have to strike a balance between a complete guide covering every possible aspect (with the risk a newbie just passes out from fear looking at it) OR you create a guide covering the basics and hope the reader if confused with take on further reading. I get people moaning about my guide saying its too basic and also people moaning that its too complicated. They are few and people who find the guide useful are many so I am happy with that.

I always amend my guide if I get a few people saying the same thing.

I'd always encourage people to have a go at writing one themselves and getting it reviewed for accuracy because the more info available the better.

I did find Andys guide confusing but I cant knock folk who are willing to invest time and effort to get this stuff made. I know from experience my own guide took a boatload of time to do. Its getting the pictures, making diagrams, writing text, proofing it, turning it into a nice page layout. I cant recall how long the collimation guide took but I would bet it was at least two days work and probably more.

My view is if it helps a single person not to have frustration then its worth it.

If I had clearer skies I wouldn't bother writing guides cos I aint that altruistic but when you live in a country where clear skies are rare then its at least something to do to keep your own interest up and maybe help a tyro.


Post Extras: Print Post   Remind Me!   Notify Moderator  
rmollise
Postmaster
*****

Reged: 07/06/07

Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: FirstSight]
      #5670874 - 02/09/13 02:49 PM

Quote:

SO: What exactly would one need to physically do during initial setup of the secondary/primary and the collimation process to be able to get the perfectly concentric end-result shown in Andy's video?




Who cares? Joe or Jane Novice can collimate easily with his instructions, point the scope at objects in the sky, and have a hell of a good time. The images will be good, and they will not have spent time when they should be under the stars worrying about pea-picking collimation.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jason D
Postmaster
*****

Reged: 10/21/06

Loc: California
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: rmollise]
      #5670894 - 02/09/13 03:07 PM

Quote:

Who cares? Joe or Jane Novice can collimate easily with his instructions,



Our concern is not Joe or Jane who can follow his instructions and accept the final results but our concern is with John or Jan who follow his instructions and get frustration with the lack on concentricity collimation view.
You seem to belittle the challenges of collimation for beginners. Try to tell a frustrated beginner who comes to CN seeking collimation assistance that collimation is way too easy. This is the last thing that frustrated beginner wants to hear because it implies he/she is incapable of executing what is perceived to be an easy task.
Collimation is easy for me today but I always remind myself on how difficult, frustrating and scary it was when I attempted it for the first time including the confusing non-concentric view. I never tell anyone who seeks collimation assistance that collimation was too easy because I know it is the last thing frustrated beginners want to hear.
Jason


Post Extras: Print Post   Remind Me!   Notify Moderator  
rmollise
Postmaster
*****

Reged: 07/06/07

Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Jason D]
      #5670900 - 02/09/13 03:14 PM

I think you are worried about nothing. The beginners will be OK. Amateur astronomy survived seveal generations of collimation tools made of 35mm film cans with icepick holes in the bottom, afterall.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Jason D
Postmaster
*****

Reged: 10/21/06

Loc: California
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: astro_baby]
      #5670903 - 02/09/13 03:19 PM

Quote:

When I came back into this hobby from an age when there were no fast scopes I did use Andys video and I did in fact find it misleading as it showed a concentric pattern that was impossible to achieve with my F5. LOTS of other guides online showed the same thing and this created confusion to my brain...




Hello Mel,

It is always good to hear from you. I can't count the number of replies I read in astro forums that include statements such as: "Refer to Astro_Baby's guide. It shows the secondary mirror shadow shifted due to offset especially for fast scopes". All these replies are in response to beginners who get confused by the lack of concentricity and your guide has been assisting them to alleviate that confusion.

Jason


Post Extras: Print Post   Remind Me!   Notify Moderator  
astro_baby
scholastic sledgehammer


Reged: 06/17/08

Loc: United Kingdom
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Jason D]
      #5671076 - 02/09/13 05:29 PM

Thanks Jason and hi to you too and hope you are well.

The lack of concentricity totally messed up my head. More so because I was used to old fashioned slow scopes collimated with a glorified film cannister. My reflector circa 1977 had a colimation tube supplied with the scope. I cant recall its exact F ratio but it would have been about F8.

I just found the inability to get the circles concentric AND centred under the focuser was a real brain ache. Not being an optical expert I just clildnt understand why it was impossible. I cant be the only one as I see this come up on forums so often.

I have to be honest, unlike you Jason I just dont respond to collimation threads these days because it does my head in and its so hard to diagnose what a users peoblem may be from screenshots.
I know that sounds like I am being a bit of a cow but i found all my time was being absorbed answering collimation issues.

The other reason is I am not that expert, i can collimate my scope and most other scopes in my hands but I lack the theoretical knowledge to handle much else.

With regards go Andys tutorial it was one of the things that baffled me but it did at least get me to a kind of first base so it dis have its uses. Pesonally I think lasers in the hands of a novice cause more problems than they ever solve not least because most scopes dont have an accurate enough focuser to make a laser useful.


Post Extras: Print Post   Remind Me!   Notify Moderator  
droid
rocketman
*****

Reged: 08/29/04

Loc: Conneaut, Ohio
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: astro_baby]
      #5671293 - 02/09/13 07:38 PM

My dear old dad alwasy said if you want something done right ,do it your self.

Sounds like a plan ,who wants to do it???

Its easy just make a video and post it on the net.....


Post Extras: Print Post   Remind Me!   Notify Moderator  
jmartin
super member


Reged: 08/25/08

Loc: Corpus Christi, TX
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: droid]
      #5671417 - 02/09/13 08:54 PM

Worrying about the concentric rings is where collimation anxiety comes from (oh my god, it's not 1000000000% correct). Enjoy your scope and forget about it. Or make your own video simple as that. I used Andy's video and it worked great for me.

Post Extras: Print Post   Remind Me!   Notify Moderator  
FirstSight
Duke of Deneb
*****

Reged: 12/26/05

Loc: Raleigh, NC
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: droid]
      #5671650 - 02/10/13 12:14 AM

Quote:

My dear old dad alwasy said if you want something done right ,do it your self.

Sounds like a plan ,who wants to do it???

Its easy just make a video and post it on the net.....




I said that back many posts ago in this thread, at least twice. That's Andy's privilige to decline to accept the constructive criticism that's been well-articulated on this thread, and keep his video the way he wants. And it is up to those of us offering the constructive criticism to eventually come up with an alternative (there, that's at least three times). The major hurdle in doing so isn't so much understanding how to present accurate material in a manner suitably clear and straightforward for beginners; rather the challenging part is creating material with high-quality production values, graphics, and animations. I'll grant Andy that his video has superb production values and graphics, is stylistically well-presented, and shows that he put a lot of effort into it, regardless of the issues many of us have about certain substantive particulars.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jason D
Postmaster
*****

Reged: 10/21/06

Loc: California
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: jmartin]
      #5671752 - 02/10/13 02:39 AM

Quote:

Worrying about the concentric rings is where collimation anxiety comes from (oh my god, it's not 1000000000% correct). Enjoy your scope and forget about it. Or make your own video simple as that. I used Andy's video and it worked great for me.




Good advice but how do you suggest passing it to beginners? Beginners do not know which alignments are critical and which ones are not. Beginners do not understand why their collimation cap view is non-concentric and if they should ignore it or not. Passing the correct knowledge to them and help them avoid getting frustrated is the point of this thread.

If Andy's video is in some obscure website then this thread would not have existed. Because Andy's video is popular and google directs beginners to it, it would be a good place to pass on these collimation related messages.

Jason


Post Extras: Print Post   Remind Me!   Notify Moderator  
apage
member


Reged: 12/13/03

Loc: Chesterville, Maine
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: csa/montana]
      #5671780 - 02/10/13 03:40 AM



Post Extras: Print Post   Remind Me!   Notify Moderator  
cheapersleeper
Post Laureate
*****

Reged: 01/22/10

Loc: Sachse TX
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: apage]
      #5671848 - 02/10/13 05:56 AM

Searched "how to collimate a Newtonian telescope" and got 24,000 hits for videos, and 1,280,000 hits total. At no point in that search did Andy's vid pop onto my screen and slap me around until I watched it, or threatened my family if I didn't. There is no problem here beyond the offended sensibilities of the pedantic.

Over the few years I have been on this site, I have seen plenty of bewildered, ready to throw scopes out the winodow beginners, and they were not watching the video in question. They were reading the hundreds of pages of arguments here regarding collimation along with constant suggestion that they immediately acquire 400 bucks of collimation tools to be able to enjoy their Craigslist telescopes.

This hand ringing is not about the poor beginners, it's about being RIGHT.

Calm down, people.

Regards,


Post Extras: Print Post   Remind Me!   Notify Moderator  
Bob S.
Carpal Tunnel
*****

Reged: 07/14/05

Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: cheapersleeper]
      #5671871 - 02/10/13 06:36 AM

+1 for Cheapersleeper's comments. My collimation cap works perfectly for my f/3 scope (just kidding). However, we do tend to get rather a..l (orofice body part) about collimation and it becomes very confusing for beginners. I cringe when I hear a beginner expousing complex collimation terms that only confuse their appreciation/understanding of basic Newtonian collimation. Rick Singmaster of Starmaster Telescopes has pointed out to me on numerous occassions that a relatively poorly collimated scope as seen in an autocollimator still shows fairly decent images.

I remember teaching one of our clan how to do collimation using hand puppet illustrations of scope component movements to take it out of the realm of the complex with all of the jargon. This person rapidly moved on to become quite expert at collimation with his 18" f/4.3 scope and I am sure can now easily connect the dots between the esoteric and the practical.

Edited by Bob S. (02/10/13 09:53 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jason D
Postmaster
*****

Reged: 10/21/06

Loc: California
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: cheapersleeper]
      #5672093 - 02/10/13 10:20 AM

Quote:

Calm down, people.




Good advice that applies to all of us including you.

Despite the intended message of this thread has been re-iterated many times, this thread keeps getting derailed.

This thread has never been about collimation tools or about how to collimate or about how much to collimate. It is about editing or adding an addendum to make Andy’s popular collimation video even better.

Maybe it is time to lock this thread.

Jason


Post Extras: Print Post   Remind Me!   Notify Moderator  
FirstSight
Duke of Deneb
*****

Reged: 12/26/05

Loc: Raleigh, NC
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Jason D]
      #5672156 - 02/10/13 11:17 AM

Quote:

Quote:

Calm down, people.




Despite the intended message of this thread has been re-iterated many times, this thread keeps getting derailed.

This thread has never been about collimation tools or about how to collimate or about how much to collimate. It is about editing or adding an addendum to make Andy’s popular collimation video even better.

Maybe it is time to lock this thread.

Jason




I agree that we've reached a point where all relevant, substantive discussion-points have been made and critiqued. Although the faction who maintain that the errors in Andy's video are nonexistent or at least harmless are simply wrong IMHO, they have nonetheless correctly laid down a valid challenge: SO SHOW US by coming up with something better, something that is at the same time a correctly accurate, yet easily understandable collimation tutorial, which BTW has quality graphic and production values.

The first step toward something like that might be to take a separate thread to work on a rough script or storyboard for such a potential presentation, before (and without at all) committing anyone toward proceeding further into the nitty-gritty of quality graphics or production work. Even if we never advanced such a project into any real production stages, the chance to get a concrete proposal thoroughly critiqued by the CN membership would still be a valuable exercise. A clear, simple, concise instructional tutorial is anything but that to create. Rambling on in complex jargon is easy. Explaining things accurately, yet clearly in a way that strips off obfuscating jargon is much more difficult, yet doable with thoughtful effort.

Edited by FirstSight (02/10/13 11:24 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
jmartin
super member


Reged: 08/25/08

Loc: Corpus Christi, TX
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Jason D]
      #5672165 - 02/10/13 11:22 AM

I was about as much a beginner as I could be when I first used the video, then as time went on I got better with what I was doing. As will most new astronomers. It is a good basic reference point for what will work for most people.

Post Extras: Print Post   Remind Me!   Notify Moderator  
FirstSight
Duke of Deneb
*****

Reged: 12/26/05

Loc: Raleigh, NC
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: jmartin]
      #5672204 - 02/10/13 11:44 AM

Quote:

I was about as much a beginner as I could be when I first used the video, then as time went on I got better with what I was doing. As will most new astronomers. It is a good basic reference point for what will work for most people.




There's lots of us, me included, who saw Andy's video at relatively early points in our experience with reflectors, who thought at the time it was helpfully good, and yet managed to successfully evolve out understanding past its limitations. The problem is that the particular inaccuracies contained therein are totally unnecessary sacrifices for serving the interests of a clear, basic, correct presentation for neophytes. This isn't a case like learning downhill skiing, where teaching snowplow and stem turns are often necessary inferior compromises in technique before someone is ready to learn parallel.

However, IMHO we're past the point where the anecdotal evidence presented by one side vs the other are going to change anyone's mind.


Post Extras: Print Post   Remind Me!   Notify Moderator  
howard929
Member
*****

Reged: 01/02/11

Loc: Low End of High Ground
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: FirstSight]
      #5672252 - 02/10/13 12:14 PM

Chris,

If you're going to do it or if anyone else here does it. All I'd suggest is Make it simple. Make it concise. Leave out all the "I need a grounding in optics, 2 dictionaries and 3 spell checkers" just to make sense of it. Compete with Andy, and make it easy for beginners to understand and to do. ie: Leave out those overly complicated optical path drawings. Include: if you see that, turn this screw this way and watch it correct itself. Make it so that the message isn't how smart you are but how easy it is to do.

Howard


Post Extras: Print Post   Remind Me!   Notify Moderator  
FirstSight
Duke of Deneb
*****

Reged: 12/26/05

Loc: Raleigh, NC
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: howard929]
      #5672269 - 02/10/13 12:23 PM

Quote:

Chris,

If you're going to do it or if anyone else here does it. All I'd suggest is Make it simple. Make it concise. Leave out all the "I need a grounding in optics, 2 dictionaries and 3 spell checkers" just to make sense of it. Compete with Andy, and make it easy for beginners to understand and to do. ie: Leave out those overly complicated optical path drawings. Include: if you see that, turn this screw this way and watch it correct itself. Make it so that the message isn't how smart you are but how easy it is to do.

Howard




I'm in complete agreement here. Despite having gained a progressively more sophisticated understanding of collimation, I'm not (yet) any sort of advanced expert myself, and still find myself stumbling through the loose scree of jargon as I work myself gradually toward the mountain-top (if a top to this mountain even exists; it does, so I'm told, but I haven't seen it yet myself). However, OTOH one of the best ways to master a subject is to learn it well enough to teach it to someone else, which process also has the sharp-pointed edge of often ruthlessly exposing the remaining holes in one's own understanding.

Edited by FirstSight (02/10/13 12:35 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
jgraham
Postmaster
*****

Reged: 12/02/04

Loc: Miami Valley Astronomical Soci...
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: FirstSight]
      #5672279 - 02/10/13 12:28 PM

I'm looking forward to your instructional video.

Post Extras: Print Post   Remind Me!   Notify Moderator  
howard929
Member
*****

Reged: 01/02/11

Loc: Low End of High Ground
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: FirstSight]
      #5672293 - 02/10/13 12:38 PM

Quote:

However, OTOH one of the best ways to master a subject is to learn it well enough to teach it to someone else,




IME in this world there's no connection there. Knowing certifies but doesn't necessarily equate to the actual ability to teach.


Post Extras: Print Post   Remind Me!   Notify Moderator  
FirstSight
Duke of Deneb
*****

Reged: 12/26/05

Loc: Raleigh, NC
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: jgraham]
      #5672298 - 02/10/13 12:40 PM

Quote:

I'm looking forward to your instructional video.




A little premature to promise anything concrete will yet come of this. One of the things I greatly respect about Andy's video is how obviously much necessary work and time he obviously put into it to make it a quality production rather than just another guy-with-webcam-and-scope humdrum youtube video, the latter of which could be done this afternoon without making any really useful advance in what's already available.


Post Extras: Print Post   Remind Me!   Notify Moderator  
howard929
Member
*****

Reged: 01/02/11

Loc: Low End of High Ground
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: FirstSight]
      #5672318 - 02/10/13 12:48 PM

BTW - wish to see a good teacher teach? Hang around the Beginners forum and see if Jon Isaacs doesn't personify what it means to be a teacher.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Jason D
Postmaster
*****

Reged: 10/21/06

Loc: California
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: FirstSight]
      #5672347 - 02/10/13 01:15 PM

Quote:

One of the things I greatly respect about Andy's video is how obviously much necessary work and time he obviously put into it to make it a quality production rather than just another guy-with-webcam-and-scope humdrum youtube




Andy's profession is an online course developer. It is his expertise as evident by his collimation video in terms of animation and narration.

Jason


Post Extras: Print Post   Remind Me!   Notify Moderator  
astro_baby
scholastic sledgehammer


Reged: 06/17/08

Loc: United Kingdom
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: Jason D]
      #5672551 - 02/10/13 03:15 PM

Purely personal thing, i dont really like video tutorials, i fond them tough to concentrate on and while I am thinking the video has moved on. I prefer written instructions with pic and diagrams which is what I tend to create.

One of my jobs was training sales staff years ago so I have some training experience.

As already said I would always encourage people to have a go themselves. You might lean something in the process as much as anything.

I have refrained from posting a link to my guide lest it be seen as self promotion but I am always up for learned criticism of the guide.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jarad
Postmaster
*****

Reged: 04/28/03

Loc: Atlanta, GA
Re: Andy's Shot Glass Video - Wish He Would Correct It new [Re: astro_baby]
      #5672668 - 02/10/13 04:44 PM

Okay, I agree that the substantive points have been made, and we're going in circles now. Time to put this one to bed.

Thanks,

Jarad


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | 3 | 4 | 5 | (show all)


Extra information
18 registered and 22 anonymous users are browsing this forum.

Moderator:  ausastronomer, Knuklhdastrnmr, Phillip Creed, JayinUT 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 4216

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics