Scale of 12" dob...

[Naemeth]

Dumb dob question here, what's this Paracorr I keep hearing about?

A Coma Corrector by TeleVue.

http://www.televue.com/engine/TV3b_page.asp?id=61

[emadmoussa]

Ah, I see. Thanks!

[SnakeyJ]

Thanks Moonshane for highlighting your earlier post on EP Comparisons at F4 - certainly food for thought, I was under the false impression that that the low focal ratio reflectors would be almost useless for visual without the expensive Paracorr or matched coma correctors.    Your impressions with even the budget EPs suggest that for visual they can still give very reasonable views.    Though I do appreciate that the collimation will need considerably more attention at F4 than F5 - though for a static setup in my new obs this could be far simpler to maintain.

Certainly food for thought with a 10" quattro replacing the 200P - though a mount upgrade will have to be on the agenda!

[mitchelln]

I've just got a Baader MPCC MKIII coma corrector for my 300P. I'll let you all know how I get on with it once we get a clear sky!

[Moonshane]

Thanks Moonshane for highlighting your earlier post on EP Comparisons at F4 - certainly food for thought, I was under the false impression that that the low focal ratio reflectors would be almost useless for visual without the expensive Paracorr or matched coma correctors.    Your impressions with even the budget EPs suggest that for visual they can still give very reasonable views.    Though I do appreciate that the collimation will need considerably more attention at F4 than F5 - though for a static setup in my new obs this could be far simpler to maintain.

Certainly food for thought with a 10" quattro replacing the 200P - though a mount upgrade will have to be on the agenda!

that's another misconception re collimation I feel. although you are right in a way that you need to be adjusting the average f4 primary (especially a larger one) a little more often than say a f5 mirror, the process is exactly the same and both need to be adjusted accurately to get the best from the scope; neither is more difficult and if you can accurately collimate an f5 you can also just as easily do so for an f4. e.g. my 12" f4 needs the most minor of tweaks to the primary only (often I don't bother it's so close). bear in mind that my observations were with relatively narrow field plossls and might have been very different had I been comparing a cheap 82 degree eyepiece with my Nagler.

[emadmoussa]

Let me know if you want any more pictures of my 300P. I could show how it fits in my car, for example.

Sent from my GT-N7105 using Tapatalk 4

Yes please.

[mitchelln]

Yes please.

Right-ho. I'll lug it down to the car at some point over the next day or two

[AlexB67]

Emad, Have seen this video ? it gives also a fair idea of the size and weight setting up a 12 inch. Doesn't seem to me he is struggling with it  exactly.

http://www.youtube.com/watch?v=bDY8extsWH8&list=PL89258EB0849037F4&index=9

Edited September 26, 2013 by AlexB67

[SnakeyJ]

that's another misconception re collimation I feel. although you are right in a way that you need to be adjusting the average f4 primary (especially a larger one) a little more often than say a f5 mirror, the process is exactly the same and both need to be adjusted accurately to get the best from the scope; neither is more difficult and if you can accurately collimate an f5 you can also just as easily do so for an f4. e.g. my 12" f4 needs the most minor of tweaks to the primary only (often I don't bother it's so close). bear in mind that my observations were with relatively narrow field plossls and might have been very different had I been comparing a cheap 82 degree eyepiece with my Nagler.

Shane,

That's ok - nothing in the EP case over 70deg fov at present and most are 60deg!    The ES82s or even Naglers are a long way down my wish list for the time being as I'm slowly mulling the CCD and imaging rig in the observatory and currently have the 6" achro on the lawn for visual - though this may go in favour of 10-12" dob at some point (three might be pushing things on both the domestic and storage side).

I do have the Standard SW Coma Corrector, which many have used @F4 on their quattro's - though it's really designed for F5 and the Parracor, Rowe and the new SW Aplanatic should be better with wider fields at F4.

All good stuff to think of, though I'm subverting Imad's original thread so will go away and ponder this for a while.

[emadmoussa]

Emad, Have seen this video ? it gives also a fair idea of the size and weight setting up a 12 inch. Doesn't seem to me he is struggling with it  exactly.

http://www.youtube.com/watch?v=bDY8extsWH8&list=PL89258EB0849037F4&index=9

Thanks Alex. This seems doable actually. Having looked around though the only 12" dobs I could find were flexitube and I am actually after a solid tube. Any idea where to get the 12" Skyliner from?

[AlexB67]

Thanks Alex. This seems doable actually. Having looked around though the only 12" dobs I could find were flexitube and I am actually after a solid tube. Any idea where to get the 12" Skyliner from?

http://www.telescopehouse.com/acatalog/Skyliner_300P_12__Parabolic_Dobsonian_Telescope.html

They do them at telescope house, though I have no experience buying from them ( but sold out right now, sorry did not spot that ) . I agree, they seem to be hard to find from searches so far.

Edited September 26, 2013 by AlexB67

[TractionMan]

Here's the 12" Flextube packed in a tiny Nissan Almera getting ready for an astro meet last night. Got room for the observation chair as well.

Edit typo.

Edited September 29, 2013 by TractionMan

[starwonder]

Is that packaging round the OTA what came with the scope originally?  Although not quite as big as that monster I was wondering the safest way to transport a SW Skyliner 200P about in the car for taking it to dark site places.

[AlexB67]

FWIW. I could fit a 10 inch solid tube just on the back seat of my KA, but it would not roll all the way back, as the back seat narrows and it would not sit well. I think it is easy to underestimate how easy and well you can pack these things so you do not end up denting the OTA during transport and leave room for nothing else. I could even squeeze a 12 inch solid  tube OTA if I put the rear and left front seat forward, but again the packing and protection would leave much to be desired and leave no spare room for much else at all. If planning  on going to a dark site on a regular basis or even a small trip away it is worth considering these things carefully. It is the main reason I settled for a 10 inch flextube in the end, in spite of the fact it costs more. 

All in all, I think that  borderline when a scope is that little bit too big and cumbersome, for me anyway to carry or to get it in a car would quickly result in me using the smaller scope more often, bringing that instead. As is often said, in many ways, the best scope is the one you'll use most often

Edited October 3, 2013 by AlexB67

[starwonder]

Indeed AlexB67 that's why I have opted as my first scope, which I want to use at home and at dark sites, to be the SW 8", because although I would have preferred a 10" looking at the picture of it in the back of the car there wouldn't be enough room for my toddler's car seat!  So I thought at least the 200P would be of a size where i might be able to get it in the boot of an Octavia maybe?  Obviously I'd have to protect it though and liked the idea of that foam surrounding it but guess I could wrap it in a blanket maybe, then it wouldn't take up as much space.

[AlexB67]

Is that packaging round the OTA what came with the scope originally?  Although not quite as big as that monster I was wondering the safest way to transport a SW Skyliner 200P about in the car for taking it to dark site places.

Yes that foam is the packing that comes with it, same with mine, should be handy.  I can use that if I wanted to as well, with the solid tube I would not be able to as it would be too long for the back seat in my case. I made all the measurement of my car and the scope before deciding purchase.  I know I can even put the OTA upright on the backseat, it would leave 5 cm and tighten it perhaps with safety belt or something else for longer holiday for more efficient packing, with the solid tube I would not have those options.  if you have a  bigger car the same would apply to the 12 inch flex I guess, economies of scale as it were  .  If you got a truck and fork lift for around the garden, just  go and buy that 50 inch

Edited October 3, 2013 by AlexB67

[starwonder]

       

[John]

Thanks Alex. This seems doable actually. Having looked around though the only 12" dobs I could find were flexitube and I am actually after a solid tube. Any idea where to get the 12" Skyliner from?

I think the solid tube Skywatcher 12" went out of production a couple of years back. Shame because that would be my preference if I was looking for a 12" dob right now. It was less expensive than the Flextube is too.

[AlexB67]

I think the solid tube Skywatcher 12" went out of production a couple of years back. Shame because that would be my preference if I was looking for a 12" dob right now. It was less expensive than the Flextube is too.

I think it is a very valid point, the extra cost, had space not been a concern for car transport I'd go for a solid, the price difference in appreciable and the OTA is that little bit heavier, plus you have to slide it in and out every time, no big deal to me. Collimation is arguably not quite as stable, though form reading around opinions on that seem to vary on how much of a difference that makes, but given that for a 10 inch or above I expect in most cases be it sold or flex, the primary will need a tweak for every session more or less anyway.

I suppose the moral of the story is  when and if the flextube design is worth that extra investment. In my case it undoubtedly was because of the aforementioned, but this may not the case for everyone.

[emadmoussa]

I think the solid tube Skywatcher 12" went out of production a couple of years back. Shame because that would be my preference if I was looking for a 12" dob right now. It was less expensive than the Flextube is too.

I think this leaves us with the GSO options - apparently they're as good as the Sky-watcher - if not better. 

[mitchelln]

I'm pretty sure that if I'd had a solid 12" Skyliner rather than the Flextube, I would have bashed it on a door frame by now. Getting my collapsed 300P through a door is a delicate operation (I've sheared off one of the eyepiece screws on a door frame), I can't imagine trying to do it with a full length tube.

[TractionMan]

Is that packaging round the OTA what came with the scope originally?  Although not quite as big as that monster I was wondering the safest way to transport a SW Skyliner 200P about in the car for taking it to dark site places.

Yes it's three pieces (out of six) of packaging material that I saved for the purpose of transporting the telescope like this.

[John]

I think this leaves us with the GSO options - apparently they're as good as the Sky-watcher - if not better. 

Possibly as good, if you get one with a good mirror.

[AlexB67]

I think this leaves us with the GSO options - apparently they're as good as the Sky-watcher - if not better. 

This has been asked quite a bit recently, plenty threads in the forum on said topic. The way I see it,  not from experience but listening carefully, it is a bit of horses for courses really, not much in it,  Orion optics UK more expensive club aside   they all have some strengths and weaknesses.  All these companies are in competition with these mass produced scopes, if one was significantly better value than the other, one of them would stop selling such a model quite quickly I would think. I also remember as a ready to go scope and minimal modding  to start with I heard it said the SW comes out better than most IIRC.

Edited October 3, 2013 by AlexB67

[emadmoussa]

Possibly as good, if you get one with a good mirror.

At about 20Kg weight and 145cm length, I could see the hassle of moving it around.