Skyliner 150 or 200p?

[Mr niall]

Hello there, 

Yes - probably seems like a question with an obvious answer but the more I think about it the more I’m not sure.

I’m mostly interested in planets as you know, and I know the reputation that the 150pl has as a “planet killer” and this is effectively the same scope I think.

Additionally those of you that know me probably remember I had an absolute nightmare with collimation on my 130p flextube lately and I’m led to believe that longer focal length newts are easier to collimate?

And I guess the price is another factor, I realise the price between the two is less than a field flattener, or a good polar scope etc but in absolute terms it is another £65.

Anyway, not sure... any suggestions?

[Peter Drew]

For planets, I would go for the 200 model, aperture really counts. A 200 will probably have the same focal length as the 150L.   ?

[johninderby]

The 150 dob is an f7.84 and the 200 is an f5.91.

An OO150 f11 was a great planetary scope. Think it’s only available as a special order now though.

[happy-kat]

Will any difference in weight and size matter.

[xtreemchaos]

id go for the 200, newts the bigger the brighter the better and 200mm is a kinder sweetspot when you factor in the weight to size portability bit. charl.

[rwilkey]

Hi Mr Niall, the difference between the two is quite extensive.  Just to give an illustration, the 150 lets you see the largest moon of Saturn - Titan.  However, the 200P will not only show you Titan, but six other moons besides, including Rhea, Enceladus, Tethys, Dione, Hyperion and Iapetus.  For me that is a most exciting prospect as I love Saturn and its moons.  The 200P is a faster, richer field scope and as long as you use decent ep's it will serve you well for all types of astronomy targets.  Good luck with your choice!

[JOC]

A 200P and an 8mm EP will soon knock planets into shape.

[dweller25]

I directly compared 6” f/8 and 8” f/6 SW Dobs on the planets.

Both showed good visible details once cooled and collimated.

The 8” showed more detail on the planets and was a little better on deep sky objects.

The 8” is the same length as the 6” but more capable.

[Waddensky]

If the difference in weight doesn't matter to you, I'd recommend the 200p. It's faster than the 150p, but holds its collimation very well. The planetary views are more detailed and there are lots of other objects visible that cannot be seen with a 150 mm Skyliner.

[fiestazetecmk2]

200p great scope.as said aperture is king.probably the only scope you'll ever need.enjoy the sky.

[Ruud]

In this aperture range, for planets, the limiting factor will be the atmosphere rather than the aperture. 

Larger apertures intrinsically allow for higher magnification, but they also pick up more atmospheric seeing, which degrades the image.

I would choose a 6" f/8, which is also less sensitive to eyepiece quality and collimation errors.

 

[ronl]

200p, I love mine, and it's very manageable, super views too.

[johninderby]

Dare I suggest the 250? Better all rounder than the 200 and still not too big and heavy for most people. Of course this causes “budget creep” but then this is normal in this hobby.  ?

[Mr niall]

Thanks all some fab comments there and no @johninderby I think more than doubling my initial budget is slightly more than budget creep, more like “budget smashed to pieces with a hammer” haha. Although a 10” would be quite cool... ?

[Red Dwarfer]

I have a number of scopes and while they all get used from time to time , my 200P stands out by far as the most used .... as they say on here , your best scope is the one you use the most .

[Red Dwarfer]

8 hours ago, Peter Drew said:

A 200 will probably have the same focal length as the 150

Both 1200 mm 

[johninderby]

But the important bit the focal ratios are different. F7.84 vs F5.91.

[N3ptune]

I think a 10" is big and cumbersome, the 8" is big too but not has annoying has the 10" (Especially my 8" which is only 1000mm long against a thick and long 10" dobson based). I tried the 10" against my 8" and the 10" is beating it on nebulae and other DSOs.

But, because of the weight and size, the 8" still wins for me.

So, between a 6" or a 8" for me the choice is purely a matter of size and weight, comfort.

If this can help.

[JOC]

A truss tube 200P runs in at exactly F6 - different focal length to the fixed length ones.   Easier to store and transport too.

[Mr niall]

44 minutes ago, JOC said:

A truss tube 200P runs in at exactly F6 - different focal length to the fixed length ones.   Easier to store and transport too.

Looks like it’s only available on goto though?

[Mr niall]

9 hours ago, happy-kat said:

Will any difference in weight and size matter.

Nah not so much, 20 years of amateur rugby has pretty much destroyed every major joint and muscle group already...

[Stu]

This is presumably for visual @Mr niall?

Focal ratio is far less important for visual, particularly f6 vs f8. The only difference it makes is the relative size of the secondary and thus a theoretical increase in contrast. If you were comparing f5 with f15 then different story but this is not the case.

The focal length of the two scopes is the same, so eyepieces will give the same mag in both scopes, the difference will be a little increase in resolution and perhaps colour perception in the 200P due to the larger aperture and brighter image. The 200P is no more a rich field scope than the 150P; both will give the same field of view with a given eyepiece. 

The 150p is the same length but lighter and a little more manageable, it is a surprisingly capable scope, I've looked through a couple and always been impressed. It will be a balance of the 150 possibly cutting through the seeing a little better vs the additional resolution and light grasp of the 200. Do you have any particular targets in mind? If budget is tight and getting the 150P allows some better eyepieces then that may make some sense otherwise 200P probably best.

[JOC]

Viewing position may also be an issue (depending on how they are mounted) and what your back is like - I tend to immediately think of both these on Dob mounts, but of course they can both go onto tripods with rings (at least I think they can).   My 200P and yes it is a Goto (I don't actually know if you can get it non-goto, but a truss tube version might not lend itself to a tripod mounting fixture) is on a Dob base - it's a little on the low side (I am not short), but it is excellent seated on a couple of bar stools set at 2 different heights depending on sky angle.  A 150P is even smaller on a Dob base - I think some folks even put these on tables.  So although this thread is about what the sky is going to look like through them don't lose sight of how you intend to mount them and whether this will either encourage you to spend lots of time with them or not in terms of the height they might be viewed from.

[Mr niall]

12 minutes ago, Stu said:

This is presumably for visual @Mr niall?

Focal ratio is far less important for visual, particularly f6 vs f8. The only difference it makes is the relative size of the secondary and thus a theoretical increase in contrast. If you were comparing f5 with f15 then different story but this is not the case.

The focal length of the two scopes is the same, so eyepieces will give the same mag in both scopes, the difference will be a little increase in resolution and perhaps colour perception in the 200P due to the larger aperture and brighter image. The 200P is no more a rich field scope than the 150P; both will give the same field of view with a given eyepiece. 

The 150p is the same length but lighter and a little more manageable, it is a surprisingly capable scope, I've looked through a couple and always been impressed. It will be a balance of the 150 possibly cutting through the seeing a little better vs the additional resolution and light grasp of the 200. Do you have any particular targets in mind? If budget is tight and getting the 150P allows some better eyepieces then that may make some sense otherwise 200P probably best.

Hi Stu - Thanks, yes just for visual use. Yes mostly planetary really, and then just general surfing over the winter, mostly messier hunting, lunar and showcase doubles. I’ve only got one good eyepiece - a vixen NPL 30mm, so maybe could justify another...

I was, ironically, going to get an eq35m for Christmas but in all honesty when I started doing the sums (power pack, laptop, scope, possibly guiding, possibly filters possibly a field flattener, possibly a new camera) it really hits home just how cripplingly expensive this hobby can be. ?? feel like I’m losing my way a bit and feeling a little depressed and overwhelmed.

I really just need something I can chuck out in the garden and enjoy the star stuff with - as simply as possible! And these two seem right up my street.

[Waddensky]

4 minutes ago, Mr niall said:

I really just need something I can chuck out in the garden and enjoy the star stuff with - as simply as possible! And these two seem right up my street.

Absolutely, this has 'dobson' written all over it. Both Skyliners are great scopes at a decent price, including fairly good two eyepieces. I'd still go for a 200p because of the larger light-gathering power and better resolution, but it's indeed a bit more expensive than the 150.