Benefits of a laser collimator?

[lhuchison]

Just thinking aloud here , i,m doubting the benefits of a laser for collimating. Nothing to do with the technical side of these great tools its just that someone like me, who borders on having ocd! keeps checking time and time again.

I cant walk past my reflector without testing again for perfection. i use it now to check my refractor, i cant stop testing that now!

When i use my cheshire, it seems to just do the job and i dont keep trying to get it even better.

So the laser is going back in its box until i really need it.

Does anyone else over-test their 'scope, especially as we've had nothing but rain for ages?

[Sepharus]

I'm still trying to figure out which is best for me, just bought a SW200p, wondering if the extra cost of the laser is worth it?

[Tinker1947]

I installed these knob, with a laser i can collimate in less than a minute, whether its dark or not....

[JamesM]

Lasers ability to collimate your scope is very much dependent on how well collimated the laser is itself. I suppose the assumed precision that using a laser implies will always raise people's expectations of what can be achieved hence the seductive need to fiddle and fettle for the optimum performance. I am no different to you in having collimated by Hotech laser collimator over a difference of some 24 ft - which is totally unnecessary but because the option is there (...and it is cloudy again) you have to keep yourself busy! Laser collimators do have at least two distinct advantages, being that you can tune up a big long dobsonian by yourself and instantly witness the results of adjusting the main mirror without having to get up off the floor to travel all the way down to the other end of the scope, the other being that you can collimate your scope in the dark should you have to adjust it 'in the field'.

James

[lhuchison]

I would still recommend the laser , sepharus, I use the hotech laser, very precise . And the sw200 is a great 'scope.

[Bart]

Try the barlowed laser technique, flipping easy and accurate. Overcomes issues with laser collimation as it relies on the the reflection of the centred circle on the primary. It was a revelation to me

http://www.cameraconcepts.com/barlowed%20laser%20collimation.pdf

Barry

[John]

Try the barlowed laser technique, flipping easy and accurate. Overcomes issues with laser collimation as it relies on the the reflection of the centred circle on the primary. It was a revelation to me

http://www.cameracon...collimation.pdf

Barry

Great suggestion Barry. I use the barlowed laser approach myself and it seems more accurate than the non-barlowed approach, for primary collimation anyway. Secondary collimation still needs a well collimated laser though.

[Bart]

Great suggestion Barry. I use the barlowed laser approach myself and it seems more accurate than the non-barlowed approach, for primary collimation anyway. Secondary collimation still needs a well collimated laser though.

You're dead right John, you need to get the secondary sorted first. But its a fantasticly (?) quick method. Sometimes when I feel swotty, I use the cheshire afterwards to get absolutely dead on, especially if I'm chasing the GRS or other planetary stuff

[lhuchison]

You're dead right John, you need to get the secondary sorted first. But its a fantasticly (?) quick method. Sometimes when I feel swotty, I use the cheshire afterwards to get absolutely dead on, especially if I'm chasing the GRS or other planetary stuff

Good info guys, now i,m going to try the barlowed method. Is there no end to this collimation thing!

[Vince1963]

Try the barlowed laser technique, flipping easy and accurate. Overcomes issues with laser collimation as it relies on the the reflection of the centred circle on the primary. It was a revelation to me

http://www.cameracon...collimation.pdf

Barry

That's great Barry... I have a Cheshire which i thought was just the job and with regards to Leons question, i don't check mine that often, But after reading this i'm not so sure. I have a fast 200 Dob, so it looks like i will benefit from a laser.

[lhuchison]

Bit off topic but How do you like the dual axis motors Vince? I was thinking of upgrading

[Sammyb]

Thinker1947 - where did you get those knobs from?

[acey]

I agree with the OP, it's easy to end up obsessing about collimation when in most cases it matters a lot less than sky quality. But we can't fix the sky so we spend time and money fiddling with the scope.

Most lasers are well enough collimated out of the box and fiddling will probably only make it worse. Most important thing is the focuser, including any adaptors used to hold the collimator. Just give a laser a gentle nudge or rotate it in the focuser to see the effects.

I collimate my 12" flextube at my dark site before every session. I use a laser to get the secondary tweaked (I too use "Bob's knobs" - http://www.bobsknobs.com/ - to make this bit easy). Then a cheshire for the primary - a red light shining on the angled face of the cheshire lets me see what's going on. Whole thing takes a couple of minutes. Then I forget about collimation and get on with the interesting stuff.

[Moonshane]

collimation should be as close to spot on as you can get it but I prefer looking through my eyepieces on the whole

the thing to bear in mind is that heavy eyepieces, a less than solid focuser, a long focal length, a mirror cell that does not hold the mirror firmly in position can all affect the collimation as you move the scope around so get it right and then just enjoy the view. check the primary if you want to every now and again through the evening and tweak things if necessary as this is the most critical part. more importantly, just use the scope and enjoy it