SingAstro

@antares2063 - An out-of-collimation newt should be relatively easy to collimate right? Unless it needs some tools which you didn't bring along or did not manage to buy there. The collimation "hassle" may be worth it in return for the bigger aperture in Australia instead of restricting yourself to smaller aperture scopes?

Other than refractors, MCT can be be quite short also. For example, the Skywatcher Mak127 is only about 14 inches long and can hold their collimation as well as refractors.

I use your old 5" Mak as my travel scope. Plus a 13mm eyepiece and a barlow to provide 100-200x mag is all I need. Never left collimation, felt confident enough to leave any collimation tools at home. Spent hours staring at 47 Tuc on a moonlit night
Regarding collimation, as Gary knows, it takes me about 5-10mins to achieve collimation on my 14" Dob using only a laser with barlow attachment so its actually no big deal. Carrying a small plastic container with tools if needed is a small issue.

What about the ultra compact truss-tube dob? Is it cabin-approved?

Gary: yup did collimation using a far light on top of a building, wasnt there purely for astro/stargazing only I was also trying to suggest to see if lin00b prefers lighter camera tripods over GEM...haha

Edit: one of the most "xiong" collimation ever...didnt own any collimating tools back then

cloud_cover: yup the Astele tube is solid , i think nothing much can jar the alignment =P (Off topic: 47 Tucana globular...wow you must have travelled far south!)

lin00b: take your time to consider , and as Gary mentioned before, try to join observing sessions to get a feel of the different scope systems/setups

Regards,
Junwei

antares2063 wrote:lin00b:

The most airline portable scope i feel (in my opinion) is a 80-90mm refractor with retractable dew shield. (the dew shield can slide inwards and outwards, hence making the overall tube length shorter)

Speaking from personal experience, when i was young i lugged a Celestron 150mm Newtonian with CG4 and aluminium tripod legs to go Australia with an army friend . Didnt pass security so had to check in all luggage. Collimation was horribly out when we landed at Aust.

If you wish to hand carry the scope up the plane, i think only a refractor can make it.
In addition , in future if u want to branch out into imaging, most refractors have average f-ratio (f6-f9) making long exposure times unneccesary. Hope this helps.

Regards,
Junwei

ouch, thats what i was afraid of. once went on a hiking trip with a walking pole. the pole did not get through airport security, end up abandoning it behind. (travelled budget, so no checked luggage then)

and so my scope size shrinks again, 5"? 4"? how's nebula visual from a 4-5" aperture?

a dob would be far from my first choice. as that rules out ap completely, if i understand correctly. how does a dob perform visually on uneven ground?

lin00b wrote:and so my scope size shrinks again, 5"? 4"? how's nebula visual from a 4-5" aperture?

Generally better than a smaller aperture scope which may have slightly better contrast. Most nebulae are generally fuzzy, dim, non high contrast objects. So the light collecting ability provided by a bigger aperture scope may be more critical. If its not big enough to even catch the dim light to see the object, then don't even bother to compare contrast among different smaller scopes because you may not even see it well enough of even at all in the first place.

lin00b wrote:a dob would be far from my first choice. as that rules out ap completely, if i understand correctly. how does a dob perform visually on uneven ground?

Visual performance is more related to the optics and build of the dob.

For uneven ground, depends how uneven it is. If it is only slightly, should not be a major problem since most dobs have some sort of "feet" attached to its base which raises the whole base above the ground slightly. Some DIY portable dobs may allow the user to attach a tripod underneath it (see Gary Seronik's dob mentioned earlier).

For a non-tracking manual dob, slightly uneven ground may not be too big of an issue. Since the user usually doesn't wish to or cannot use a dob to observe objects very near to the horizon. If the ground is too uneven, then it is most probably not suitable for deployment for other non-dob designs too.

spent the weekend looking at some tubes and more or less has my eyes set on a 6" cat. mount wise i'm currently lusting over the new ioptron zeq25.