Collimatable collimator!

[Jiggy 67]

It really is personal preference, some people prefer a Cheshire, others a laser, I’ve tried both . I prefer a laser (HoTech, which I think is a premium bit of kit) and you’re right, a laser is quick and easy in the dark if you need it. 
The Cheshire V Laser argument has been repeated a hundred times before on this forum and will repeat a hundred times again, it never gets resolved because it’s all about preference 😀

[Pixies]

As for using a Cheshire in the dark. As it's likely only a final check while the scope is cooling, just hold a red torch up to the side-window and look for that satisfying annular ring around the eye hole. If it's not perfectly concentric, just tweak the primary adjusters until it is - it's only likely to be slightly out.

If it's miles out, perhaps if you've dropped it on the way outside(?) then a laser might speed up the collimation.

[popeye85]

I've just decided to bite the bullet and get a Hotec-my first laser and to be honest I've had nothing but problems with it. Already sent one back and it is looking like the replacement might be going the same way......

Going to preserve with it though. The combination of ease of use in darkness plus not having to go back and forth between the primary and focuser is the big pull for me.

[AlexK]

4 hours ago, popeye85 said:

I've just decided to bite the bullet and get a Hotec-my first laser and to be honest I've had nothing but problems with it. Already sent one back and it is looking like the replacement might be going the same way...

I have already gave a hint on the fact that at least 90% of old astro market players can't really compete with China on many positions anymore as their old high-tech is actually so mainstream now that a perfect laser diode can be purchased for $1, while those in their collimators are barely c10 in a batch. As a result, today, that old $150 Hotech is actually on par in quality at least by points at the dedicated task of a Newtonian collimation with a $20 noname china collimator. I would even speculate that these Hotech lasers are made in China for $10 a piece. I.o.w.: the higher price-tag on astronomy merchandise doesn't always means a better quality. The above thread confirms that conclusion very well I think.

My advice, if you still need basic astro stuff like a trivial laser collimator get it from China now, as China knowledge of the open market grows fast. I have purchased that $25 laser collimator linked above for just $13 shipped only 14 months ago. Soon the price on it will be on par with that Hotech as they are practically the same thing...

Edited December 2, 2020 by AlexK

[John]

5 hours ago, Jiggy 67 said:

It really is personal preference, some people prefer a Cheshire, others a laser, I’ve tried both . I prefer a laser (HoTech, which I think is a premium bit of kit) and you’re right, a laser is quick and easy in the dark if you need it. 
The Cheshire V Laser argument has been repeated a hundred times before on this forum and will repeat a hundred times again, it never gets resolved because it’s all about preference 😀

The quandary begins when you get what you think is good collimation with one device then find that the other does not agree. You then get the scope collimated with the other device only to find that the original one thinks it is off

At least you can use a star test to act as a "referee"

[Jiggy 67]

33 minutes ago, John said:

At least you can use a star test to act as a "referee"

Absolutely!

[Jiggy 67]

Just when you thought it was all over 😀.....what about the Concentre 

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p5506_TS-Optics-Concenter-2--Collimation-Eyepiece-for-Newtonian-Telescopes.html

I have got one and uses it once to centre the secondary under the focuser......but it will completely collimate a scope......just widening the debate, sorry 

[AlexK]

1 hour ago, Jiggy 67 said:

Just when you thought it was all over 😀.....what about the Concentre 

That's basically a combination of Cheshire and universal sighting tube. Concentric rings in the middle of the FOV are for different scope apertures (but surely could be leveraged as additional visual references on a particular one). The proper sighting tube need to be calculated for a particular scope. See the first link in my blogpost here with all the theory behind it.

[jacobingonzo]

Brendan out in the field I can check collimating using the Cheshire and a small torch - shine it in the indent in the Cheshire and you can make any adjustments necessary 

 

j

[BrendanC]

Thanks all.

Lots of thinking to do.