Who here purchased a laser collimator and found...

[Dean]

While waiting for my laser collimator to arrive, I wondered....

Who here purchased a laser collimator and found...that your previous collimation attempts by whatever other optical (looking through eyepiece etc) method was pretty darn good and when you put the laser collimator in, you didn't need to make any adjustments at all (or only very, very slight ones)?

Just interested to hear stories of good (or bad) pre-laser manual collimation :)

[multiweb]

The laser will help you get that initial alignment started but visual collimation and start test are the icing on the cake. Don't rely solely on the laser. If you're good optically it is very likely your laser will be also bang on but the reverse is not true.

[jjjnettie]

I just used an old film cannister with a pin hole in it for collimating my 10". When I got a mate to test it with his laser, it was spotus onus!!

[troypiggo]

Your scope is latin? :)

[jjjnettie]

It understands a smattering Troy, but we won't go there.

[adman]

I have found that it is easy to get lazy with the laser. It is reassuring to get that little red dot centered, but it can hide a multitude of problems....especially if your laser itself has dodgy collimation.

I have found that I get better results from a visual collimation - and it looks better down the drawtube than when I do it with the laser....

If you use the laser as one of a few collimation tools, it will be more obvious if your laser has issues, than if you use it as your only tool

[Steffen]

Yes, if the laser collimator is out of alignment you're going to mis-align the scope. This is an important thing to fix (and regularly check). Also, check for the proper location of the primary's centre spot. The one on my son's 8" GSO was off by about 5mm. And while I had the cell out I also loosened the clamps to get rid of three-lobed stars…

Cheers
Steffen.

[Dean]

Well my collimator finally arrived (long story)... It is the Orion Deluxe Laser Collimator. I had previously collimated by eye using the old photo tube cap method. I thought I was fairly close.

Anyway today I put in the laser collimator and got to work... I checked if it was way out itself (i.e the laser itself was centered in its tube) and as far as I can tell it was fairly close. No obvious or major deflection as I rotated the tube... not much anyway. So with that said I switched it on and did the paper check at the end of the scope so I wouldnt be looking right down the beam reflecting off the glass. I didnt get an obvious beam showing, more a glow... So I quickly peeped down and found why... the beam was just passing on one of the outside edges of the secondary mirror so it was neither on or off the secondary entirely. The beam projected onto the primary was about an inch or so off center. I kinda suspected it would be off.

Anyway a few adjustments of the secondary and I had the beam located at the center point of the mirror. No with the secondary locked in place, its to the back of the scope (10" Dob) and to adjust to get the laser lined up on the angled target on the collimator. It was just showing on an outside edge of the target. A few adjustments here and its centered and locked back down. A quick check again down the tube and the secondary is still projecting on the the center point of pirmary.

After removing laser I looked again through the tube by eye and everything looks better visually too.

So it will be out with the scope tonight if the clouds behave and I'm hoping to get the crispest images yet. I must admit I was getting pretty good and clear images of the moon the other night, but some stars did seem slightly blurred toward the edges of the view, although that could be the crappy plossls I am using too?

Anyway just a report back to say my visual was close, but I will hopefully find tonight that the laser has made it even better... :)

[erick]

Dean, with your laser in and switched on and the mirrors adjusted so the beam is going where it should, move your scope from horizon to zenith and see if the laser spot moves much on primary mirror or on the return target on the laser. This can be useful to see if you have any movement or flexure. Don't be surprised to see a mm or two of movement. No movement would be great. If there is much movement, then try to work out why and fix it. The primary mirror cell sagging a bit on its support springs is a common cause, if that is the way it is mounted. One thing to do if there is movement is to choose where you will be observing - say an elevation of 60 deg or so - and tweak the collimation to spot on at that elevation.

By the way, after I have done a reflector with the laser collimator, I find the cheshire agrees very closely.

Tell us how it goes. :)

[allan gould]

Try Al Sheenys collimating program for that final touch up. I can thoroughly recommend it. I thought that I was just a tweek off perfect and using his program made it spot on for my scope. A great program.

[rockytop]

Can anyone or two help with a providing simple process for using a Glatter holographic laser to collimate my 14" LX200R?? Thanks and cheers!

[pjwdesigngm]

I use a Hotech laser to get my 10" DOB as close as possible. Then, I use a Cheshire to fine tune the primary. I think this method is as close to using the star test for optimal collimation as possible. This can be done in daylight whereas the star test is not. Think of aligning planes, not one spot, the mirror surfaces are curved, but they still need to be aligned as close as possible to 90 degrees to the optical path describe by the laser.
My thoughts on this. Hope it is of some use.
"Watch the Sky"
Paul

[Steffen]

I haven't used a Glatter collimator in an SCT and I'm not sure what can be adjusted on an LX200, but I've used it many times in my Intes Maksutov, which is probably somewhat similar.

I first use the Glatter without holographic attachment, just with the white screen. The screen can be seen reflected in the secondary mirror which in turn is reflected in the primary. I adjust the secondary so that the return beam coincides with the laser source.

Then, with the holographic attachment screwed in, I point the scope at a wall and adjust the primary mirror so that the projected pattern is perfectly centred and symmetrical.

This brings me pretty close to good collimation. I finish it off with intra- and extra-focal star images. Once done the scope holds collimation very well (unlike a Dob).

Howie Glatter has some quite detailed instructions on his site (http://www.collimator.com/coltext.htm), covering SCTs as well.

Cheers
Steffen.

[AdrianF]

I made the mistake of relying on the laser collimator to collimate the 10"GSO, and stuffed it up completely. The Dob is sitting in the corner of the room unused, I will attempt to recollimate it again one day soon. By eye.

Adrian

[Dean]

Well I got the scope out for an hour or so last night (was bloody cold).. with its fresh laser collimation.

Result.. perhaps a slight improvement but nothing out of this world. Still getting sharp and clear images of everything within reason, so it is certainly not any worse. I seemed to be able to resolve more detail and more stars in omega centauri cluster so that is a plus. Even managed to find M104 for the first time!

Will try the above checks too and see how I go. This dob's primary seems to be mounted on threaded screws throught he frame that the glass is mounted to, if that makes sense. with stop-screws sitting next to it. No springs.

[Moon]

Funny you should ask this. I collimated my newt without any tools at all, I just eyeballed it every which way and checked the shapes of the stars on the CCD image. I took delivery of an Infinity XLK autocollimator yesterday and was surprised to find it was almost perfect.
James