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Baader Laser Collimator


Kai

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I had a chance to try one of these out at the Sgl get together in Wales on my Sct.

The unit itself is very straight forward,you just insert it into the focuser and turn it on.

You will then see (hopefully) a reflected red dot on a screen.All you then do is adjust the secondary (in my case) until the reddot is in the middle of the screen and there you go Perfect collimation :)

Time wise i suppose it took no more than a minute :)

I also watched Steve collimate the big Dob he brought down for the event in no more than 5 minutes.You have to be aware that the scope was assembled from new at the event AND he had to put the mirror into the mirror cell :shock: before he could assemble the scope,this was both primary and secondary collimation.

Now i would have no hesitations in collimating any scope when it is that easy.

It seems like another of those "Black Art" myths have been laid to rest :D

Btw i didnt purchase one :lol:

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Steve took the time to collimate my 10" Dob with one of these (cheers Steve! :) ) and it took him seconds, he really did make it look easy! Its a definite addon to my 'must buy' list!

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where did you order your bobs knobs? Direct, or from the UK somewhere?

The laser collimator sounds good, let me know how you get on wth it (will give me something to do in the evenings, because lets be honest, right now the weather kind of sucks...)

EDIT: http://eclipse.madiedo.com/impresioneseng.html#lasercoli

this device correctly collimates the optics of Newtonian reflectors only, and not the optics of Schmidt-Cassegrains...

Is this correct?

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where did you order your bobs knobs? Direct, or from the UK somewhere?

The laser collimator sounds good, let me know how you get on wth it (will give me something to do in the evenings, because lets be honest, right now the weather kind of sucks...)

If you get one of the laser collimators you won't need the Bob's knob as it's so easy to do indoors. I saw Steve do Steve's SCT and it was sooo easy. I'm tempted myself.

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I discovered recently that there is a degree of uncertainty regarding the usefulness of using a laser to collimate a Schmidt Cassegrain telescope.

Googling the subject reveals mixed opinions: Some claim that a laser cannot collimate an SCT whilst others say it is the best tool for the job.

Baader themselves acknowledge that is is 'not an easy task'.

http://www.optcorp.com/pdf/Baader/LaserColliInstructions.pdf (page 9)

Can anyone can shed some light (scuse the pun!) on the subject?

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I've got a little experience with shining a laser up the back of a cat. It's not very conclusive with a standard laser collimater as the return light is fairly spread out. Baader claim a narrow beam for their unit which would help.

When I had my OMC140 I wondered about collimation, so I did the Google thing and, having nothing better to do, ended up with the laser up the focuser. The secondary mirror is convex, so the return beam is divergent. This makes the "spot" rather large and so awkward to see and awkward to centre on the laser return target. It didn't help me collimate as the secondary of the Mak. is fixed. What I was trying to do was spread the beam enough to illuminate the primary a little, but it didn't work out as the spread wasn't enough. You don't collimate Mak's that way anyway.

Captain Chaos

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Thanks KK,

I am confused. I used the Baader laser collimator to collimate a Maksutov skyliner 102 by simply placing it directly into the rear and adjusting the screws at the back in the usual way. It worked! The spot responded to the adjustments I made to the primary and it was a simple matter to centre it, and the collimation was spot on. But from your post and some other reports - that shouldn't have happened. (I can only think that the screws were adjusting not only the mirror but the entire back).

Kai's Celestron C8 SCT was also a breeze. The spot was easily visible and centred by adjusting the secondary's collimation screws. I appreciate you can only collimate the tilt of the secondary but that is normal for an SCT.

Either the Baader is better than people realise or I am missing something :scratch:

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I was going to wait until Auntie FLO had some more in stock before I purchased, but noticed on Saturday that Greenwitch had some in stock, so I took one.

The collimation in my NS8GPS appeared to be fairy good (star test) but it was certainly off centre by enough for me to think about adjusting it. Stuck the Baader into the VB, adjusted the screws..... and it was done. 5-10 minutes tops.... I havent checked it against a star since (blumming c***ds), but will report when I can.

One thing I did notice was that it didnt take much to move the Baader in the VB, and move the return laser point on the etched screen. It also got a LOT worse when I inserted the diagonal and checked it again (way off!).

I think I`ll see how the star test goes. BTW, should the collimation be done after the scope has "cooled"?

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Steve,

I was always instructed to collimate the scope on the mount and after it's cooled down.

Most people collimate their scope indoors on a cloudy night then take it outside on a cold clear night and do a star test...

And then wonder why the collimation is out...

I may be wrong min, but it makes sense to me..

Greg

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Either the Baader is better than people realise or I am missing something :scratch:

I think the most important point on SC collimation is at the end of that Baader doc where it says that you need to make sure that the secondary is central. I'm not sure how the hell you would be able to check that, or indeed if it's possible to move it.

Very decent of you Steve to raise this.

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The same applies on the newts mind you, as the laser will always be able to be centered with the secondary after adjusting the primary. The trick is to ensure good collimation of the secondary so that it is centered and then using the laser to ensure the primary is centered with the secondary. The error can be seen quite easily in that if you place the laser lined up with the eyepiece screw and collimate then turn the laser 180 degrees to the other side the center is out. So basically I have marked the scope, the laser etc so that it always goes in the same way and in the same place.

I Must admit, I was carrying out the collimation in a warm(ish) garage then taking it outside to the cold and after it cooled I could see the difference in where the laser went to, not much but not the same. I have now got into the habit of doing the collimation outside when the scope is cooled. Also when it is on the mount slightly raised.

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How good a fit in the focuser is the baader? The laser collimator I have is not very good in the focuser, if you rotate in the focuser the beam is all over the place and yes the laser is collimated.

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There was a little 'slop' in my original focuser which the instructions said could be compensated for by putting the laser in in a certain position relative to the tightening screws on the focuser which worked reasonably. Since upgrading to a MoonLite things have improved although there's still a little play. It translates to less than 1/4 of an inch on the primary at the most. Thats still enough to screw up my collimation in theory but I put it in the same way everytime and collimate to that. Once its in the usual position I don't wiggle the laser and the results seem to be OK. The Baader itself fits in more snugly than my Cheshire eyepiece (or for that matter any of my eyepieces!)

James

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