Which Collimator?

[jamie@bristol]

Hi guys, im buying a Dob 200p very soon and in preparation for this im about to buy a Collimator. Ive found one at FLO but was wondering if its for use with the scope im getting. Its the Cheshire Collimating eyepiece, Any help would be greatly appreciated. Sorry if its a noobish question.

[Llamanaut]

not at all, its as individual as as the user... personally i use the hotech laser and have never had any problems, i collimate everytime before i use it and have got the procedure down to about 30 seconds....i know others hate lasers and would rather align their mirrors by sight, and still others dont collimate at all... best thing to do is to read up as much as you can and go with whatever you feel is right for you, i know astro-baby here on the forum has an excellent collimation guide on her website... Hotech's are expensive (£98) but in my opinion they pay for themselves with crisp clear views. You'll have fun with the 200!!!!

[RikM]

I agree that it's a personal choice. Of the lasers, the Hotech seems to get the best/most recommendations and they certainly are quick and easy to use. But then I use a £15 Cheshire and get really good results with that (and have done side by side comps with laser collimated scopes at observing evenings) so feel no personal need to splash the cash for a laser.

Rik

[Talitha]

My Meade laser's very simple to use and can be used in the dark. Since i like to tweak things a few times a session, it's perfect for me. From what i understand, the regular collimating tools need daylight in order to use, but i may be wrong on that.

[RikM]

I have used the Cheshire in the dark by shining a red light torch on the reflective disc, but it certainly wasn't easy. I tend to either set up in the daylight or from home, I can use my kitchen light shining out into the garden to give it a final check then turn everything off ready for observing.

I guess a laser would be much easier to use in the dark.

Rik

[jamie@bristol]

Thank you for your help, Im going to go with a laser collimator so i can tweak my scope whilst out observing in the dark. Ive found a skywatcher Collimator with 1.25" and 2" adapter for £35 on Ebay. Should be here in a few days.

[johnkirkpatrick]

remember you will first have to collimate the laser its self, cause if the laser is not collimated then your scope will also be out. Do this buy making a jig that the laser can be sat in and rotated around on and watch the laser point on a wall about 10meters away and if the point shining on the wall stays in the same place then all is good and stick it into your scope, but if it scribes circles on the wall the laser needs to be collimated.

[Llamanaut]

same can be done by rolling it along a flat surface whilst switched on

[fatwoul]

I first tried a laser, and then discovered that the laser itself wasn't collimated (SkyWatcher laser, so maybe avoid that model). I collimated it as best as possible, but never really trusted it to give me a reliable collimating from any angle of rotation.

So then I got a basic, standard Cheshire collimator, which I think gives good results, but I didn't find the process easy or instinctive. I'm sure it comes with practice.

I also discovered the idea of the barlowed laser collimator, which I like very much as it allows the use of a relatively shoddy laser, but still gives very accurate results. Have a search on SGL or Google for this process, because I can't remember where I found it, but it's quite nifty.

So I use the Cheshire for bench collimations, and collimations if I arrive on site when it's still daylight, but I use the barlow laser for nighttime field collimations. The combination seems to work well.

[johnkirkpatrick]

I use the barlowed method my self works very well, But you can only collimate the primary mirror this way, so I just use the ep holder dust cap that came with my scope and drilled a 2mm hole in it for collimating the secondary mirror.

[jamie@bristol]

Wow, some good advice, and really useful tips too. Thank you for your help, ive just ordered the Collimator and it should arrive in a few days. If it is out of allignment ill do what i can to remedy this myself, but if its not no doubt ill be pestering you guys for help hopefully though it will be fine. Thanks again.

[Talitha]

My Meade laser didn't need to be collimated in order for me to use it, but i've read reports by Amateurs who've had problems with theirs... no idea what brand they were using, though.

[johnkirkpatrick]

I have a "Astro Revelations" laser and it was way out.

[Jason D]

I use the barlowed method my self works very well, But you can only collimate the primary mirror this way, so I just use the ep holder dust cap that came with my scope and drilled a 2mm hole in it for collimating the secondary mirror.

A collimation cap does well with the primary mirror but not as well with the secondary mirror.

A slightly misaligned unbarlowed laser collimator can produce results comparable to the collimation cap, even barlowed laser, for the primary mirror as long as the laser beam is centered in the primary mirror center spot. That is, perfectly centering the laser beam in the center spot is more critical than perfectly aligning the laser collimator in its case.

http://stargazerslounge.com/equipment-discussion/103503-laser-collimators-not-all.html#23