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Venusia

Which type of Collimator?

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Oh and the cats eye site tube XL for getting the secondary in the right place and making it round.

Sent from my AWSOME iPhone using Tapatalk

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It's a free forum and I'm not breaking any rules.

I'm not listing them for you if you cannot remember your manners. They cost nothing!

TheThing

Still evading the question!!

It is apparent you can't come up with a single error in AB's guide.

I rest my case.

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I'm not going to bother stooping to your level. You have no manners and obviously can't be bothered to look for yourself. I could't really care less. Follow the guide and get it wrong. It's your scope and your life. Good luck to you. :p

TheThing

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But full of errors. For more comprehensive read over complicated! It makes it into a chore rather than a simple job.

TheThing

I think a lot of people, especially beginners, are directed to ABs method when collimation is queried. It would of great benefit to them, and the community, if you could outline some of the areas of ABs method that you think could be improved on. It would prevent beginners becoming frustrated with what can seem a complex operation.

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If any beginners want to find out, then feel free to PM me and I will put them straight.

I wont put anything here for 'the troll' to pick apart because, frankly, I'm not in the mood to have him argue with me or forget his manners further. That kind of behaviour is best kept for American forums.

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Well I, for one, would appreciate you posting publicly and trust the mods to prevent any trolling behaviour. I need to properly learn how to collimate a newt for when I sort my 10" and would probably refer to A_B's guide as she has clearly spent time putting it together for other people to benefit from. Surely it is in everyones interest to clear this up peacefully and avoid all the animosity which seems to surface every time.

Stu

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Agree with Stu and BlueAstra's post, AB's collimation guide is what I have followed from the start and if I'm doing something wrong I'd like to know.

I dont think Jason D is a troll, he's just asking the same question as the rest of us....where are the errors in Astro Babies collimation guide??

Edited by Mike73

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JasonD has spoiled it for the rest of you I'm afraid. Take it up with him. I can't be bothered to try and sort out the chip on his shoulder.

The distinct possiblity is that if I post them here, he will simply 'troll' thru them arguing every point that he doesn't agree with, regardless of others experience. He seems over protective of A-B's guide which is peculiar. Perhaps his style of posting is better suited to the forum that has something to do with overcast skies between the hours of dusk and dawn?

Anyway, I'm not going give him any reason to continue the spurious arguments he has started on. Harsh for others, I know, but it's down to our Californian "friend"!

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TheThing, with all due respect here, what Jason D doesn't know about collimation isn't worth knowing.

Please see some of his posts on Cloudy Nights before suggesting he's a troll. If he suggests AB's guide is fine then I'd tend to believe him.

http://www.cloudynights.com/ubbthreads/showflat.php?Cat=0&Board=reflectors&Number=3033065

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JasonD has spoiled it for the rest of you I'm afraid. Take it up with him. I can't be bothered to try and sort out the chip on his shoulder.

The distinct possiblity is that if I post them here, he will simply 'troll' thru them arguing every point that he doesn't agree with, regardless of others experience. He seems over protective of A-B's guide which is peculiar. Perhaps his style of posting is better suited to the forum that has something to do with overcast skies between the hours of dusk and dawn?

Anyway, I'm not going give him any reason to continue the spurious arguments he has started on. Harsh for others, I know, but it's down to our Californian "friend"!

Not really the attitude is it!?

If you think there are errors in something then please feel free to point them out so we can all learn, dont go getting defensive when someone disagrees with your opinion or challenges you to back up your statement with evidence. You quite clearly accuse JasonD of trolling whereas I cannot find anything wrong with his posts - be careful there!

Lets please get this thread back on track with some productive debate to help the OP. Any more degeneration and offending posts will be removed and the thread will run the risk of being locked - you have been warned.

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Really? I couldn't give two hoots!

That doesn't excuse him trying to throw his weight around here and trolling other peoples experience. I can't be bothered with his childish, rude nature or lack of basic manners. If that makes him a collimating expert on Cloudy Nights and in his home country, then he can stay there.

Take it up with him, don't berate me for his problems.

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Perhaps this post should get back on track, I find the posts on SGL very useful but when they degenerate into gainsay they are no good to anyone.

I'm beginning to wish I hadn't mentioned Astro Babys Guide, which I found easy to follow........other guides are available of course. :grin:

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Find them for yourself. They are quite obvious!

TheThing

@ Thing:

I'm a beginner at collimation, so if you could actually tell us the errors in AstroBaby's guide, it would be really helpful for us less knowledgeable members.

Regarding collimation, I have a question:

My new 10" Newtonian has 4 clips. Out of the box, I can only see 3 of the clips when looking down my Cheshire or the coll cap - so does this suggest the secondary is out of alignment?

I don't want to muck around with the secondary unless it is already out of collimation...

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As far as guides go, I've probably looked at numerous online guides, some over complicated and very scientific, others just plain confusing (for me), find the one that suits you and your level of intellect, from memory I used both Andy's shot glass and AB's, but then just read the instructions that came with my Hotech and follow those. Part of the problem here is we are dealing with peoples personal preferences and no one likes to hear the one they use might not be as good as someone else's, everyone wants to believe they use the best system as it then gives them belief that what they are doing is best. What we all need to remember is to remain objective and give the correct help and advice to the Original Poster, arguing amongst yourselves helps nobody, nor paints a pretty picture to newcomers of our great forum.

lets get back on track, I'm using a Hotech and Farpoint Auto Collimator for very fine adjustment, but have to say the Farpoint came with no instructions, and I'm still learning it's use!!!

I like my Hotech laser, it is very well built and the laser is factory aligned in it's housing at the factory, it has a very neat self centring fit in the focuser. Now I know lots use Cheshire's , but to add balance, plenty of folks also use lasers with great results. I think the Hotech is one of the best laser collimator's out there, but this comes at a cost at over £100. I do find it simple to use, whether it be in daylight or night, I think the only improvement I would like to see would be a finer laser beam.

As far as the FarPoint, I'm gonna have to get in touch with the manufacturer for their instructions.

Collimation is a science in itself and takes time to learn, but once mastered will probably be the most important step to good viewing you can make, it's a bit like polar alignment, there are many different ways to skin a cat (so to speak)

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Please keep this civil. Hugh clearly has some issues with Jason (I cannot see for the life of me why) and we had perhaps better leave that side of it alone to allow this otherwise useful thread alone.

I use a Cheshire and find it is perfectly fine for even an f4 scope.

As far as I am concerned AB's collimation article is a good guide although in some ways too thorough as it makes collimation seem a lot more complicated than it actually need be.

my view of (visual) collimation is as follows:

  • ignore the focuser position. this is usually factory set and any small misalignment can be adjusted out via the seconday or primary.
  • just do a basic check on the vanes one time only to ensure they are central and equally spaced. then forget them.
  • using a cap with a 2mm hole, and with a piece of paper held between the secondary and primary - get someone else to hold it if required. check the secondary (reflective part) is round and central in the focuser when looking down the 2mm hole. this also usually needs to be done once/infrequently.
  • insert your cheshire and adjust the secondary (using the three adjusters at the top of the tube) until it the cross hairs are central on the primary donut reflection. be careful that the secondary is always secure and I recommend collimation is done with tube horizontal. again this is an infrequent adjustment but a check is recommend.
  • next the primary and this is a case of adjusting the bolts on the bottom of the tube to put the the black dot in the centre of the donut. this will need to be done regularly.

So you'll see that once you have checked everything, the only regular adjustment is that of the primary which takes about 10 seconds to check and 10 seconds to adjust.

For visual it's really as simple as that.

I have to say that showing someone this process is 100x easier than trying to write it down.

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Thanks Shane, very useful.

Quick question, is collimation possible without a centre spotted primary?

Stu

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it is certainly possible Stu but would depend more on subjective analysis with the eye rather than aligning things up. broadly if everything looks roughly concentric then your views should be good enough. personally, If a scope I had didn't have one, I'd put one on. I have of course been referring to newtonian collimation and know nothing about SCTs etc.

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Quick question, is collimation possible without a centre spotted primary?

Only if you have a very large focal ratio telescope. At the focal ratios we're using nowadays you'll be hard pressed to get good planetary views without accurate collimation and you can't achieve accurate collimation without a centre spot. The only exception might be primary tilt alignment using a star test (which doesn't require a centre spot). But the star test won't help you adjust secondary tilt (as far as I know).

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Thanks, I was talking about newts too. I have an old OO SX250 which I will need to learn to collimate. It needs plenty doing to it , has a rubbish focuser and thick two vane secondary support but I'm looking forward to spending some time sorting it. Will complement the mak nicely.

Stu

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insert your cheshire and adjust the secondary (using the three adjusters at the top of the tube) until it the cross hairs are central on the primary donut reflection

Nice post mate, but could I just add here, and this seems to be the main bone of contention when people read AB's guide (she doesn't mention the centre spot at this point and just stresses the importance of getting all 3 clips in view), is that all 3 or 4 of the primary clips do NOT need to be visible for you to be properly collimated. As long as your secondary is showing a circle directly under the focuser and the crosshairs of your Cheshire are on top of the centre spot you're axially aligned, having all 3 clips in view just means you can see the full reflection of the primary thus gain the maximum light.

That's my understanding anyway, but please feel free to correct any duff info...

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As long as your secondary is showing a circle directly under the focuser and the crosshairs of your Cheshire are on top of the centre spot you're axially aligned, having all 3 clips in view just means you can see the full reflection of the primary thus gain the maximum light. That's my understanding anyway, but please feel free to correct any duff info...

Yes, that's true, but the cross-hairs and centre spot is the axial adjustment signature for secondary tilt. Don't forget the cheshire surface and centre spot, which is the alignment signature for primary tilt. Primary tilt is the more important adjustment since it has tighter tolerances. You need both of these tilt adjustments to be minimised to have achieved axial alignment.

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Sorry, yes, I should have said that was only for secondary tilt.

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Some very useful comments here. I was fine with my old 6" F/8, but am struggling a bit with the F/4.3 minidob of the kids. I will place a proper centre spot on the mirror, which should solve quite a few problems.

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