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120 mm f8.3 Collimation

Started by RGM , Oct 20 2003 04:47 PM
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9 replies to this topic

#1 RGM

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Posted 20 October 2003 - 04:47 PM

I bought just the OTA and recieved no instruction manual. I checked the Skywatcher web site and their link to collimation did not work. I have the collimation eyepiece, but do not know exactly how to use it. I see 2 disks, one green and the other orange. They were not on top of each other, so I assumed the telescope was out of alignment. I adjusted to optics so that the 2 different disks were on top of each other and the dots in the center of each disk were seen as one dot. Did I collimate correctly? Thanks for your help. Bob

#2 Guest_**DONOTDELETE**_*

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Posted 21 October 2003 - 07:16 AM

Not being familiar with that scope this would be a guess, but I'd say you did it right. That's what I would have done.

How's it look at night?

#3 RGM

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Posted 21 October 2003 - 11:03 AM

It has been cloudy for the last week. Looks like things are going to clear up by Thursday. I hope to see an improvement. Bob

#4 Trever

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Posted 21 October 2003 - 11:40 AM

can you buy these collimation eyepieces for refractors?

Trever

#5 Guest_**DONOTDELETE**_*

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Posted 21 October 2003 - 02:47 PM

Yep, as long as the two reflections are centered upon one another and appear as one, your scope is properly collimated. At least that's what the Orion manual stated when I collimated my scope.

Just out of curiosity (sorry to barge in on your post Bob), but how will the optics differ in a properly collimated scope to one that isn't?

#6 Guest_**DONOTDELETE**_*

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Posted 21 October 2003 - 03:18 PM

ScottI,
If its the focuser out of alignment then everything outside of the center of view will be comas, serious violet chromatic abberations, and you cant focus perfectly, I had one I just fixed that exp. this. Never had a mainlens out just pinched optics so someone else will have to kick in. I would imagine its close to being similar tho to the focuser being out other than pinched optics I imagine. Dave

#7 RGM

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Posted 21 October 2003 - 04:27 PM

Trever, My local store just gave me one. It is the one that is suppose to be supplied with all the various "Chinese" refractors being sold under different names. I was happy with my telescope even with it out of alignment. Can't wait to see if it is better. Bob

#8 Guest_**DONOTDELETE**_*

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Posted 21 October 2003 - 09:24 PM

This link provides an article which contains a photo of an out of collimation refractor. The same photo shows a collimated one, albeit an apochromat. The same principle applies with each.

http://www.cloudynig...views2/TMB5.htm

What you want to see is "concentric donuts".
I have a 70 mm. refractor which I tested for collimation with a cheshire eyepiece; fortunately it was O.K., because this scope's objective has no means of adjustment.

#9 RGM

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Posted 22 October 2003 - 07:30 AM

Starkid, thanks for the link. That is what I saw and what I ended up with. Just can't wait for a clear night to check out the results. Bob

#10 Stacy

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Posted 22 October 2003 - 02:56 PM

Could sombody explain the "collimation eyepiece" to me? How does it work? Does it have a lens?

Thanks!

Regards,
Stacy
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