Looking for a decent planet hunter.

[Jw00lgar]

Hi SGL,

Looking for a bit of collective wisdom; I'm thinking about getting a scope mainly for planetary and lunar observing, possibly with some DSO hunting thrown in.

I've read lots and lots (and lots) of threads suggesting a Skyliner 200p Dob or similar would be good, aperture rules and they're dead easy to use... however I've also read several suggestions that a decent Frac (I'm not looking to spend ££££'s here) punches through poor seeing better than a Dob and offers nicer views generally. Something like an EvoStar 90 or 102 on an eq3-2?

 

So as you can see, I'm a bit lost! Basically I'm after a good all rounder with particular attention on planetary and lunar. Any advise welcome

 

Thanks in advance 

James

[Moonshane]

A 200mm f6 dob will provide better views of solar system objects on average than any refractor in the same sort of price range

[laudropb]

The main difference between a 102 mm frac and a 200 mm Dob is the extra light gathering of the Dob. You will be able to see much fainter objects. As an all rounder scope I personally think the Dob wins hands down, but there are many who will swear by francs. It is all down to personal choice. It is a good idea to try to visit a local club and see for yourself before making your choice, if that is at all possible.

[John]

Hi James,

I like using refractors but I think I'd still recommend an 8" F/6 dobsonian. I have a very nice 4" refractor but it won't beat 8" newtonian optics.

 

 

 

 

 

[Charic]

1 hour ago, Jw00lgar said:

Hi SGL,

I've read lots and lots (and lots) of threads suggesting a Skyliner 200p Dob or similar would be good, aperture rules and they're dead easy to use... however I've also read several suggestions that a decent Frac (I'm not looking to spend ££££'s here) punches through poor seeing better than a Dob and offers nicer views generally. Something like an EvoStar 90 or 102 on an eq3-2?James

The Refractor is a closed system and no central obstruction, so less time needed to cool the scope, and no obstruction  affecting the image, No spikes on the stars. Thats one of the reasons folk like their Refractors.

My original choice was between the TAL100 and the Skyliner. I've still not had the chance to even see a TAL100 up close, but sources have told me my Skyliner is better for my general needs.

As for punching through poor seeing, I have also been informed on many occasions, that even when the seeing is not so good, more aperture still prevails, as more aperture collects more, allowing you to see fainter, even under the same described conditions.

 

[NotSoSuperNova]

I'd recommend that you go for the Dob. I looked through both when buying a scope for the first time but from the other perspective (DSO first and then maybe planetary). I decided on the 10" in the end but as a cost effective all rounder you can't go wrong. 

The fracs are great for planetary & lunar but you'll fall off as you start looking towards DSO's. So you may have to make a choice based off that.

[Peter Drew]

You can stop down a 200mm reflector down to 80mm with an off axis mask to provide the equivalent of a 80mm APO refractor for £0.  

[NotSoSuperNova]

2 minutes ago, Peter Drew said:

You can stop down a 200mm reflector down to 80mm with an off axis mask to provide the equivalent of a 80mm APO refractor for £0.  

What equipment would you use to carry out such an upgrade??? A holey sock perhaps.

[Peter Drew]

225mm diameter cardboard disc with a 80mm diameter off axis hole cut out of it.  

[Moonshane]

 

 

[Charic]

I often stop down when  solely viewing the Moon, just by leaving the dust cap on,  removing the 2" aperture cap. 
This will affect some  parameters, but it sufficiently   reduces the glare from the Moon for my needs.

[Linda]

Hi.

Although you tink now that you will mainly watch planets, there are only 7 of them you can watch and they are not visible all the time. I guess you will, just like me, be very soon interested in Deep sky objects.

I have gotten a 127mm Msksutov on an EQ3 which doesn't collimation and which is supposed to have a bit better optics then a reflector. But it is more lightweight and compact than a refractor. I can see the planets and see DSO's. A better scope might be better and show you more. I was more concerned at transportability and weight and choose therefore for a medium size scope. People who have compared telescopes, says that a 90mm good quality refractor can show the same objects as a 127mm maksutov.

With an EQ mount you can track an object with turning 1 axis wheel on the mount. On a Dobson you need to follow in 2 directions.

It all comes down to what you think is most important: total aperture, image quality, transportation, weight, most aperture for money.

[John]

20 hours ago, Charic said:

I often stop down when  solely viewing the Moon, just by leaving the dust cap on,  removing the 2" aperture cap. 
This will affect some  parameters, but it sufficiently   reduces the glare from the Moon for my needs.

The parameters it affects are resolution, contrast and max useful magnification which become what a 2" aperture scope would deliver.

Though I don't use lunar filters myself, if I did feel the need to reduce the Moon's light I'd prefer a decent quality filter over stopping down the aperture of the scope I think.

 

 

 

 

[ronl]

My first scope was an Evo  90mm which I still use to observe the Sun, with appropriate Sun filter, but not on the EQ3, this

mount and tripod is the weak link in observing with the Evo, is tends to move in the wind or at the slightest touch, but you do 

learn to put up with it, the Dob is the way to go, you will get great views of the planets, and also DSO's, and the 200p is great

value for money, the one thing with this hobby is you want to see more, that's why I upgraded to the 200p, go for the Dob and

that way you will save money in the long term.

[swamp thing]

16 minutes ago, Linda said:

 

With an EQ mount you can track an object with turning 1 axis wheel on the mount. On a Dobson you need to follow in 2 directions.

 

Linda

A Dob mount moves in any direction. it has no axis as such to move along. If you wish to move up and right you push it diagonally up and right. It is able to move freely in any direction. A dob has equal resistance on both bearings so that all it requires is a push in whatever direction one wants to go and it responds. This is why star hopping with a dob is so easy. One simply moves in the direction one wishes to go without the need to worry about what axis to move along.

When tracking with a dob you nudge it after the object. There is no need to go say up and then right one simply goes straight in the direction needed to follow it. It is simplicity itself.

This, along with its incredible stability and extremely fast vibration dampening is why the dob mounting is so successful. 

 

[Alan64]

This kit would allow one to have their cake and eat it, too...

http://www.firstlightoptics.com/reflectors/skywatcher-explorer-150p-eq3-2.html

One would have the EQ3 equatorial; which can be motorised in future, inexpensively, and allow for automatic, hands-free tracking of any object.  An object would remain still in the eyepiece, and for as long as one would like...

http://www.rothervalleyoptics.co.uk/skywatcher-ra-motor-drive-for-eq3-2-with-multi-speed-handset.html

Then, we have the 6" f/5 Newtonian, which comes with a 2" focusser.  At f/5, and with a focal-length of only 750mm, the telescope would be most versatile in observing everything in the sky: wide-field deep-sky objects and vistas, along with quite respectable lunar and planetary performance, and with the aid of a simple 2x barlow.  

...a celestial buffet awaits.    

[bingevader]

19 hours ago, Linda said:

Although you think now that you will mainly watch planets, there are only 7 of them you can watch and they are not visible all the time. I guess you will, just like me, be very soon interested in Deep sky objects.

The moon isn't up all the time either.

With the weather here lately, I'm not sure I's narrow my choice of target down at all!

If it's a clear night, make the most of it.

It would be a shame to have a decent bit of kit and not use it because there were no planets out and the moon had set.

And, with that said, I think the 8" dob is a might fine choice for the money.

[dweller25]

Planetary setup.....

8" F/6 Newtonian with cooling fan.

Baader Neodymium filter.

Pentax XW 7mm and 5mm eyepieces.

[Peter Drew]

However you stretch it, the best overall choice is the 8" F6 Dob, anything else at a similar price bracket is a compromise.

[F15Rules]

I'm a die hard refractor man, not least as I like to sit to observe at the "right end" of a telescope, I just don't get on with standing (for me) squinting down the side of a tube at an odd angle:-). 

 

Having said that, as a beginner, I don't think you will get a better all round single scope that can keep you busy for years than an 8" F6 reflector, and a DOB offers the best "bang for buck".

 

If your budget can stretch a bit a 6" Maksutov (not SCT) is a great scope and can often give sharper images than the Dob, albeit with a narrower field of view and higher cost. 

I suspect taking all factors into account that the 8" F6 DOB will tick the most boxes for you at this point.

 

Dave

[Alan64]

It is the focal-length of oculars, eyepieces, that determines observational versatility, and above all else.  A 32mm, being the lowest power available for most, produces a magnification of 38x with a 200mm f/6 Newtonian on a Dobson-mount with its 1200mm focal-length; whilst with a 150mm f/5 Newtonian, and a focal-length of 750mm: 23x, and a low-power quite close to that of a pair of 20x80 binoculars.   Therefore a 150mm f/5 may serve as its own finder, and as a wide-field "eye" taking in the largest deep-sky objects within our existence.

The highest practical power, in "real world" conditions, is around 200x or so; 250x on a very good night.  By barlowing a 6mm ocular, and the shortest dedicated ocular one might consider, 250x is then realised with a 150mm f/5.  I've had my own 6" f/5 up to such, and with the Airy discs of the four stars of the Trapezium beaconing in the night, their first-diffraction rings glistening, shimmering amid the swirling, ghostly "clouds" of the surrounding nebula. 

Saturn is a most special treat, when one might catch it.

One of the true all-arounders, the other being a 5" f/6 apochromatic refractor...

 

[Peter Drew]

All perfectly true but a 8" will have better resolution and nearly twice the light gathering than a 6". Big box ticks for a beginner.  

[Alan64]

An 8" f/6 Newtonian is a near-simulation of an unobstructed 165mm f/7 apochromatic refractor, granted, but the heavy, "wooden", moisture-prone Dobson-mount makes for a fixed focusser position.

For the record only, there should be no real concern in so far as the seeing in conjunction with a 200mm Newtonian; a 300mm, perhaps.

Alas, the stuff of dreams...

http://www.orionoptics.co.uk/VX/vx8-8l.html

http://www.orionoptics.co.uk/MOUNTS/dobsonianmount.html

 

However, smaller telescopes, and kits, get used more often, and travel more frequently...

http://www.firstlightoptics.com/reflectors/skywatcher-explorer-150p-ds-ota.html

http://www.rothervalleyoptics.co.uk/skywatcher-az4-1-alt-az-mount-with-aluminium-tripod.html

A near-simulation of a 120mm f/6 is quite capable in its own right, and its tube-rings allow for the rotation of the tube, and for much more comfortable eye placement.

The taking of afocal astrophotographs, simply by holding a camera up to the eyepiece, on the fly, is also much more easily realised.  A 150mm f/5 is a bright telescope; brighter than one might think...

 

[Jw00lgar]

Thanks for your advice everyone, I'll be sticking with the Dob for the time being. hopefully I'll get the Skyliner 200p OTA mounted on an EQ mount for AP at some point

Greatly appreciate all your help 

 

[faulksy]

the dob wins again. it realy is like childs play. you will love it