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RichMK

Collimating - How often?

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Hi

I'm still looking at what first scope to purchase, but one of my requirements is mobility. Being able to put it in the car, drive and set it up and start using it.

I've read up and watched videos on collimating a scope and I'm happy with the how to. It's more of a case of how often?

For example if I went for a Sky-Watcher Star Discovery 150P or 130p and I check the collimation before I put it in the car and drive somewhere (being careful, packing it, not just throw it in the boot and watching for pot holes etc) will I still need to collimate again or don't the need doing that often. Of course I'm talking Newtonian telescope.

Rich.

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I would say it was good practice to check it every time you use it with it being a Newtonian, that does not mean to say you have to or would need to adjust it. My Mak and SC scopes seem to hold collimation for ever but I check them often.

My Dob is a re-build every time type due to it's size so I have to do it, the other Mak/Newt is much more stable but again I check it fairly often, even if only a de-focused star test.

Of late nothing has needed to be checked or collimated as none of my scopes see through cloud.

alan.

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Once you know how to collimate, it takes seconds to check and just a few more to adjust, i check mine every time i use it.....

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I would recollimate when setting up at your site. Depending on collimation tools and -- more importantly -- focal ratio, this can be easy or hard. Mine is a f/4 scope so collimation is critical. I use the Catseye autocollimator tool and typically need to make a few minor adjustments at the start of the session. Don't forget that you have plenty of time to collimate anyway while the scope is cooling, and maybe a final quick check when cooled for the obsessive (not me!).

At f/5 or so things might not be so critical, but I'd still not assume collimation would entirely survive a car journey, and anyway, collimation can be fun and practice makes perfect etc etc….  :smiley: For me it is part of the routine. I will say though that on many scopes adjusting the secondary can be a real pain, and it makes sense to replace the collimation bolts and do the 'milk bottle washer' trick to make secondary movement smoother.

Martin

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I check my 12" F/5.3 dob each time I use it. It takes just a few seconds and rarely needs more than a tweak to the primary tilt. Once set, the secondary rarely seems to need adjustment.

I treat collimation the same way a guitarist treats tuning.

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+1 for Martins comments above

I would check each time you set up. It only takes a minute or so and becomes part of the set up routine

Gareth

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"I treat collimation the same way a guitarist treats tuning."

Why didn't I think of such a superb analogy - and I play guitar too (or at least used to lol). :grin:

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My scopes an F6 and I collimate every few months, what people say above is true, it does not take long but for visual at F6, if it is out by a bit you don't really notice. Mines been to numerous star parties over the years and after a long drive I collimate it, but don't bother between house and garden.

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My skylines Dob holds collimation very well even after a car journey. I just check after setting up and give it a tweak when required.

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I agree, don't collimate at home and do it at the other end. I also check at least each time I use it although usually it does no need any adjustment, sometimes a little as John says.

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TBH I very much doubt a 6" scope will need collimating very often at all. By all means check it but I doubt any adjustment will be needed. Small mirrors seldom need adjustment. How often one needs to collimate is effected by mainly two things. The quality of the cell and the weight of the primary. Most mirror cells are good enough to prevent collimation slip in small mirrors (even after car rides). It's only big scopes with weighty primaries that need frequent adjustment. :)

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