collimation????? again!!!

[Bigdaddyjeff]

Morning everyone....took delivery of my relevation deluxe collimator Thursday then spent around 2 hrs worrying whether the laser point from the collimator should actually be a rectangular marker as it is, or should be circular. Now i know i'm a relative newbie and i've looked at some demonstrations of collimation from links on here that people have posted and i'm certain my laser should be circular. I'm thinking i need to send this collimator back as it didn't come with instructions either!!! Hope some1 can help!! I'm also considering just collimating it indoors then fine tuning it by star collimation when i get chance to view!! Thanks guys and happy gazing:icon_salut:

[brantuk]

Here's the instructions:

Harrison Telescopes Ltd Revelation Deluxe Laser Collimator

I had that one and it was naff - check the cap at the end that switches it on/off and changes the dot size (which should be a circular dot). If the cap is loose send it back cos it's faulty and so flimsy it will break at the slightest knock.

If the cap is firm and functional you may have got a good one.

[bonefish]

So what is a good all rounder collimater then, at a sensible price?

[Bigdaddyjeff]

The cap on the end of mine just holds the laser in place inside the collimator. Can't actually change the shape or size of the laser marker so it's constantly a rectangular marker. I'm thinking of sending it back and opting for maybe a cheshire instead?

[DrNeb]

Here's the instructions:

Harrison Telescopes Ltd Revelation Deluxe Laser Collimator

I had that one and it was naff - check the cap at the end that switches it on/off and changes the dot size (which should be a circular dot). If the cap is loose send it back cos it's faulty and so flimsy it will break at the slightest knock.

If the cap is firm and functional you may have got a good one.

Hah! i had the skywatcher one from flo with that very problem. Martin was good enough to let me upgrade to the baader version instead at no extra charge.

they're a good bunch

[brantuk]

DrNeb - whew ! glad it's not just me lol

Jeff - sorry I can't comment on the cheshire - never used one - but others do swear by them

Bonefish - I got fed up with trying different types and in the end bit the bullet and got a 2" Hotech. I decided the price was worth it for a cracking good rock solid working tool that would last. S/h I got it for £85 - best astro item I ever got.

[Astro_Baby]

Get a cheshire, no aggro, never need collimating themselves, will last a lifetime and will collimate anything. Cheap lasers cause about 90% of the collimaging woes.

[Bigdaddyjeff]

Ok thanks Astro baby,i'm going to be sending the laser collimator back during the week and getting me a cheshire then heading back to your on line guide to help me through it....just need some clear skies next...that's maybe too much to ask!!!

[Bigdaddyjeff]

Hi Guys,got the scope out this morning thinking i'd be star collimating it after the disaster of the laser collimator experience but i was actually amazed to find out it was prety pinpoint indeed! Anyway,great great 1st proper viewing of Saturn followed and it was just amazing to see those rings so crisp:hello2:

[Jason D]

There is nothing wrong with your laser. The rectangular or oval shape is typical for beams generated by diode lasers. If you want to make it a point then you can use an aperture-stop which is a fancy name for covering the laser hole with a tape then poke a tiny hole in it. It is better to tape a small aluminum sheet then poke it with the tip of a needle. Be advised when you do that you will see a smaller beam dot surrounded by diffraction rings.

Jason

[valleyman]

Welcome to the chesire club,

[ozwebuk]

And I've learnt something too. Thanks for the post.. Plannig to purchase one or the other myself in the near future

[Bigdaddyjeff]

Thanks Jason,i've sent it back now anyway but cheers for the advice. I've got myself a cheshire on order so i'll be trying that out when it arrives.

[Adz]

Hey sorry to dredge up a week old thread. But I have just bought one of these revelation laser collimators. The light is a rectangle instead of a dot as some one has mentioned. So this is normal, and I am supposed to just collimate with it like that, or should I return it and just try something else?

[Bigdaddyjeff]

Hi Adz, i actually managed to collimate mine when it was rectangular... by luck more than judgement though!! I'm in the process of ordering a cheshire and i must admit i'm more confident star collimating it...when this pesky weathers not around!!!

[Adz]

I am going to make a v shaped platform to collimate mine as I dont think it is a problem being rectangular. I dont see how it is possibly to make the right tiny adjustments with a cheshire, anyone?

[sixela]

The laser collimator is more precise than a sight tube's cross hairs for setting the tilt of the secondary, provided of course that it fits well in the focuser and is well collimated itself. But a good Cheshire is actually a very sensitive tool for setting the tilt of the primary.

If you want a laser collimator with a precise dot instead of a rectangle, then you have quite a few choices, ranging from the Howie Glatter over the Orion LaserMate Pro or Farpoint laser collimator to the Hotech and Kendricks or Astrosystems laser collimators. My favourite (for many reasons explained in other threads) is the Howie Glatter, but it's far from cheap.

It bears repeating that even the barlowed laser collimation protocol (which is the decent way of using a laser collimator for setting the tilt of the primary) is actually not more precise than a good Cheshire or even a good collimation cap, but simply just as precise but more convenient.

[umadog]

+1 on the Cheshire.