For the 1,000,000,000,000 time

[todd8137]

HI all its the old laser or Cheshire fight in my brain again to col the reflector how many of you have a laser one ? how well does it work against a normal Cheshire? does any one live local to me that as one and could may be show me how they work and how much better,or worse a laser one fairs over the other

thanks

[dark knight]

I have a Hotech and cannot fault it, very precise and well made, laser is factory set, easy to use and see the target face even in strong sunlight. I can highly recommend this product. I would certainly not bother with the cheaper laser collimators.

[pvaz]

This is my personal experience with lasers:

I was looking to buy a laser, after reading many reviews I went with the hotech as most people said all other lasers usually came out of collimation etc. Problem is my hotech turned out to be a bit off as well. The company offered to recollimate it but I would have to pay for both way postage, which amount to about half the price of the thing. Now it sits in a drawer 'till I'm in the mood to waste a perfectly good saturday afternoon trying to collimate it. Meanwhile I usa a cheshire and am perfectly happy with the results achieved.

[kniclander]

cheshire beats cheap laser in my book. does it beat expesnive laser? dunno, can't afford one (but cheshire is good enough for me anyway)

[Damo636]

+1 Cheshire eyepiece.

[Rob]

The Cheshire 100%!!....

I have a laser and yes I collimated it... twice. Still did a rubbish job. I can collimate my scope from however far out it is with in 10 mins and know its bang on!

You need to buy a Cheshire (I use the AE one which has awsume instructions) and perfect it.. spend time collimating, then knocking it out and collimating again. Time well spent giving you experience thats worth its weight in gold.

Hotech's are all well and good I suppose. But nothing beats learning the process as a true Astronomer should.

Good luck to you.

Rob

[dark knight]

pvaz, why didn't you just send it back to the retailer you bought it from, unless of course you bought it second hand?

[dark knight]

ouch, guess I'm not a true astronomer then...

[great_bear]

Laser colimators may be worth it with an expensive scope, but they are too precise for the level of collimation accuracy and retention that most low-cost scopes provide.

What I mean is, laser-colimate a scope like the 130P. Now gently squeeze the scope across the front (spider) end (as might happen during transportation) and re-check - the laser will show it's well-off. Now squeeze it in the other direction and re-check - well-off in a different direction right? Getting it spot-on can be very fiddly. The laser exaggerates the kind of minor miscollimation that results from simple, everyday scope handling - the kind you don't actually need to worry about.

A cheshire shows much coarser collimation errors of the kind that are likely to cause you practical problems during observing.

[Rob]

I have no problem with those who wish to use them.. that said I still maintain you need a cheshire to finish a lazer collimation off?.

[JamesM]

Where lasers come into their own I believe is when you are collimating a long scope by your self. It is so much easier and quicker to be able to witness the adjustments you are making to the primary mirror whilst remaining at that end of the scope whilst looking back in the direction of the focuser to see the effect that your adjustments are making by noticing where the cross hair is situated on the lasers own built in target. Like so much in astronomy, I don't subscribe to there being only one acceptable way of doing something - each to there own.

Pvas, rather than allowing your Hotech to languish in the drawer, you can easily collimate it yourself by unscrewing the bevel that sits just behind the front barrel. You will see three grub screws that can be easily turned (very small adjustments) that will get it up and running in no time. Take a thick piece of card (maybe two) cut an accurate hole that will accept your 1.25 eyepiece holder found in your focuser. Secure the Hotech within the focuser adapter and project the beam a distance of say two meters. Adjust each of the grub screws mentioned above until the laser dot/cross hair remains fixed as you turn the eyepiece holder through 360 degrees. Got nothing to lose!

James

[spaceboy]

I spent a 6 months looking at what I "thought" was great views of the skies. The laser showed collimation was smack on and the views were great. I thought to myself why don't I get a Cheshire collimator as a back up in case the batteries were to ever go flat on the Laser. This turned out to be the best decision I have made since marrying my wife. The secondary was off, the primary was off AND the focuser was found to be a tad off. That tiny little red dot didn't tell me any of that. The trouble is the EP holder has tonnes of slack, you have to calibrate the collimator and it will show a perfectly collimated scope even if the secondary is a mile off. I still use the laser but only barlowed and only after it's already been checked with the Cheshire. I thought the views were great before but a perfectly collimated scope makes a world of difference.

[pvaz]

pvaz, why didn't you just send it back to the retailer you bought it from, unless of course you bought it second hand?

I don't really know... At 1st it toke me a few months to notice the decrease in view quality and then some to identify the source. I also got it from the US when the dollar was very cheap. Post back is about half price so I wouldn't get that much back.

Maybe I'm hopping it will be good once I take some time to collimate it. A laser is more practical then the cheshire when you need to collimate in the dark so I guess I'm hopping to make something out of it.

[studio1one]

Cheshire all the way for me. I have never found the cheshire to be untrue. If it says it is collimated and I do a star test, it is always right. It's also cheap and easy.

[Vega]

Spanner in the works.... if you have a webcam and laptop to hand just look at the airy disk on an unfocused star using a webcam and watch on screen as you collimate ;-). Great if your using a large reflector and cant reach the collimation knobs when looking down the focuser!

but... cheshire wins for me. How can you be sure a laser is exiting the collimator exactly correct. becuase it certainly has to be dead straight.

Matt

[great_bear]

A laser is more practical then the cheshire when you need to collimate in the dark

If you're in the dark why not use a star?

- one would hope that (under normal circumstances) it would only be the primary that's off since its last tweak.

[johnkirkpatrick]

Cheshire every time for me..

[Neil1194]

Ive got both. Recently bought a Baader laser. I always had a bit of a struglle with cheshire and collimation cap but got it about right. First time with laser - took two minutes to get everyything spot on according to the red dots. Checked with the Cheshire - spot on - something I hadnt been able to do with the Cheshire alone - dont ask me why.

[todd8137]

thanks for all the replies i have a cheshire but i messed the secondary mirror a little .i think never looked right since,then again it could have been thermals that made the star test i last did not sure will try and get the use of one before i buy one

[Arushin]

Hi, I agree with Dark Knight and JBM1165, Hotech laser is the absolute dogs if you need to collimate a long scope by yourself and I wouldn't bother with any of the cheaper ones. The difference it made to my 12" lightbridge before I sold it was incredible. I tried to collimate with a cheshire and it did improve the view, but being a bit of a dummy I couldn't have done a top notch job. Once I used the Hotech I got the wow factor back. Trouble is that I only used the Hotech once and then I sold the Dob, so now I have this brilliant bit of kit doing nothing. I believe it is a personal preference but I would still recommend the Hotech for inexperienced astronomers looking to get the best out of their scope.

[todd8137]

arushin hi yes that will be the route i will go i think,i want it for the 12" reflector the cheshire is ok but would like to see how a high tec one would be

[pvaz]

If you're in the dark why not use a star?

- one would hope that (under normal circumstances) it would only be the primary that's off since its last tweak.

Well the star need to be centered, so you need to go back to adjust the screws, then peak and recenter the star, and repeat this multiple times.

I've done it before but it's not nearly as practical as using the laser.

[great_bear]

I've done it before but it's not nearly as practical as using the laser.

True enough I guess; my relatively new 150/F8 with more than an arm's length to the bottom, definitely exceeds the practical length for effective Cheshire collimation - it sort of negates the point of having "quick-access" knobs, since you need to keep remembering which knobs pull in which direction since you can't see the effect whilst you tweak.

Hmmm... Maybe it's time I revisited laser colimation... It is after all, a much more robust and precise scope than the 130P

[great_bear]

Just spotted these wise words on the First Light Optics web site:

"for any laser collimator to be effective it needs to be fitted to a well-made focuser. The regular rack-and-pinion style focuser fitted to many beginner/intermediate telescopes lacks precision and rigidity"

[Rob L]

Just spotted these wise words on the First Light Optics web site:

"for any laser collimator to be effective it needs to be fitted to a well-made focuser. The regular rack-and-pinion style focuser fitted to many beginner/intermediate telescopes lacks precision and rigidity"

I started a thread on here a few months ago because I just couldn't get the same result twice with my Hotech, FLO pointed out it was probably due to the focuser in my dob not being up to the job.

I'm sure the Hotech is a great piece of kit in a quality scope with a well-made focuser, but I use a Cheshire now and haven't looked back.

EDIT - I see the OP has a Crayford so I'm sure the Hotech will to a great job.