How many members don't collimate their newtonians

[spaceboy]

Hi All

I just wondered due to the concerns some people have about collimation how many members don't collimate their scopes on a regular basis ? and are there member who don't collimate there newtonians at all through worry of causing more harm than good?

[Mr Q]

I do a star test each time out and rarely does the collimation need adjusting.

So my answer is, yes, I rarely do any adjustments and no, I check the state of the scope every night out.

[Starlight 1]

If my Scope is not right on the night I leave it just in case it may be cooling down time and them look at it in day light just in case it someing silly, before I start playing with the collimation.

Les

[RikM]

I check both of mine every time and adjust when necessary.

Not often for my 6" but every two or three sessions I will need to tweak the primary on the 10". I do have to cart it through the house over an obstacle course and just shift it in one go because I'm lazy, so that probably bounces it around some. I also don't tighten the locking screws up very much at all. They are just barely touching in fact. Not sure why, it was recommended by the owner of a large dob who taught me how to collimate. I think it was something about thermal expansion of the bolts flexing the mirror cell as it cooled. Anyway, that's what I do and it works for me. I get very nice sharp views.

[spaceboy]

I thought you don't tighten the lock bolts too much because it can cause pinching of the optics ??

[RikM]

I thought you don't tighten the lock bolts too much because it can cause pinching of the optics ??

You could well be right

[Bart]

I bring my 10" in and out of the garage on a sacktruck (with slightly deflated tyres to soften the ride!) and I find it rarely needs it. My star tests are pretty good.

Bart

[Mike73]

I check mine every time I use it.

I can completely understand anyone nervous of doing it the first time but it really is a case of the more you do it the easier it gets.

[zainraza]

I was a bit wary the first time doing it but found it to be a breeze.

Nowadays I'll only collimate it if its really bad though, but the scope stays in the conservatory and its just a case of lifting it out of the door into the garden

[Moonshane]

I collimate (or at least check the collimation of) all my newts before I observe with them and on my big dob sometimes do it during a session.

it's easy to do and I'll happily do it in the dark if required (primary anyway).

[Mike73]

it's easy to do and I'll happily do it in the dark if required (primary anyway).

Do you use a laser collimator then Shane?

I use a Cheshire and found that's fine when there's a little light in the sky (and using a torch light into Cheshire) but if the primary is really out and the center dot goes into the black then what do you do? I don't really want to use a laser collimator but maybe this would be the only time I could see it being better than a Cheshire?

[Moonshane]

I use a Cheap Cheshire (i.e. one with no cross hairs) for primary alignment as I find this easiest. if collimating the primary in the dark then I use my dim red map reading torch and shine this on the flat of the Cheshire and it illuminates the area nicely. if the collimation is well out (unusual) then I just turn one of the bolts until the Cheshire dot becomes apparent and then go from there - "turn away - check - oops wrong way - check - turn back - check - better - turn a bit more - check - OK - turn the other one - check - better - turn both in succession and check and eventually - yep - I'll live with that"

[dav1d]

Never done it. I can't face telling NY wife that I need to spend cash on yet another telescope accessory: (

Sent from my Desire HD using Tapatalk

[RikM]

I use a Cheap Cheshire (i.e. one with no cross hairs) for primary alignment as I find this easiest. if collimating the primary in the dark then I use my dim red map reading torch and shine this on the flat of the Cheshire and it illuminates the area nicely. if the collimation is well out (unusual) then I just turn one of the bolts until the Cheshire dot becomes apparent and then go from there - "turn away - check - oops wrong way - check - turn back - check - better - turn a bit more - check - OK - turn the other one - check - better - turn both in succession and check and eventually - yep - I'll live with that"

I use a cheap one with cross hairs, but the exact same method. I find that you always turn the knob the wrong way first

[paul schofield]

I have been using two different reflectors for the last 2 years and have never collimated either. I know I should, but have read a few guides and find it a bit daunting, ie I might mess it up. I keep telling myself I must do it but my scope seems fine and I dont want to make the optics worse. I have a cheshire, but its never been used yet.

[Moonshane]

I use a cheap one with cross hairs, but the exact same method. I find that you always turn the knob the wrong way first

ha ha - I do genuinely always say 'yep, I'll live with that' too - often probably too loudly.

[nicnac]

i check before use but i have only had the need to tweak a couple of times since i bought it

[tich]

When I first got mine I never touched it for a couple of months purely as I'm still new to all this. When I did start to check & collimate I sometimes found it tricky to start with but after doing it a few times all became clear & I found it to be pretty easy. I check every time now & it either only needs a slight tweak or is pretty much spot on.

[WayBig]

I only collimate mine if I'm going to try planetary imaging, for visual use I rarely collimate.

[spaceboy]

I recently broke my SW deluxe laser collimator http://www.harrisontelescopes.co.uk/acatalog/SkyWatcher_Premium_Laser_Collimator.html (name and shame as they are utter junk!) and always used this barlowed to collimate under dark skies as it's dark and can't see anything. In the process of buying a new one it dawned on me that as your only likely to collimate the primary in the dark surely a star test is the easiest and most accurate method of collimation ? I know this is not always easy for dob owners but I'm sure it's doable with a bit of practice ?

[sanmatt]

Never done it, don't know how, cant make sense of the instructions and so I don't know if it needs it or not.

[Kevin C]

I've only had my 8" dob for a couple of months and have never adjusted it.

I did a star de-focus test on the first night I used it and it looked spot on.

When I go to use it, I carry it downstairs carefully and never bang it on the floor when setting it down and take care when placing it on the stand.

I did a check last night and it still looks spot-on.

I do have a cheshire and an old film canister cap with a hole in it and looking through the eyepiece it also looks good.

If it ain't broke, dont fix it is my motto!

[swamp thing]

I transport my 10" scope by road every time I use it so I collimate every time upon arrival.

Some times it needs adjusting others it doesn't but I always check.

[umadog]

They need collimating at least once a night so that's what they get.

[acey]

I rarely collimated my 8". I collimate my 12" flextube every time I use it. Laser for secondary then cheshire for primary. Then, of course, I realign the finder. Whole thing's done in minutes.

If I turn the laser in the focuser or push gently on it then the spot goes off-centre, so I never regard the initial secondary alignment as being particularly accurate. If the cross hairs line up in the cheshire once I've adjusted the primary then I know I'm OK. If not, then I may re-adjust the secondary, though in practice it makes no real difference to the view (it just means the secondary is a little bit rotated).

My laser is itself properly collimated, by the way (I've tested it) - the fault is in the focuser, but it's no problem because the cheshire tells me everything I need to know.

My solid tube 8" f6 rarely needed adjusting, despite lots of car journeys to my dark site. The bigger, faster 12" f4.9, with its moveable upper section, is a different situation, though in practice it rarely needs much adjusting.