Wide angle DSO eye piece for SkyWatcher Star Discovery 150P

[redhat 2]

Hello everyone,

Bit of a backround: I've been a keen stargazer when in my teenage years, then couldn't pursuit my passion, but recently, in my forties, it hit me again, as I moved  and life is good (South facing large garden, obstructed only from the North by our house, but then I just move the scope further and viola!). Started with 90mm refractor, but was always thinking of reflector.

Long story short, I've got my SkyWatcher Star Discovery 150P GOTO a week ago. Bought it second hand, very good condition, and good mirror. Have got two nights stargazing, cought cold and I AM LOVING IT.

Now I would like to get me a nice wide angle ep for DSO spotting.

The scope is 150mm / 750mm f5. I've done some reading obviously, and Explore Scientific 82 degree series have all good reviews and fit within my budget. I can afford only one, and apparently  the best for DSOs is the one that gives 2mm exit pupil. Now, for my scope that would be 10mm piece, and that is not within ES 82 degree range, so it's down to 11mm (2.2mm exit pupil) or 8.8mm (1.76mm exit pupil).

My question is: which one would be better for my rediscovered passion? I'm gonna be using that ep for faint mostly.

Thanks to  everyone in advance for any kind advise.

Edited October 17, 2019 by redhat
tag

[midatlantic61 16]

11 hours ago, redhat said:

I'm gonna be using that ep for faint mostly

150mm aperture for faint DSO?
hmmm...
How are your skies? Light pollution?
Feels you might have purchased the wrong scope for this task in the first place...
The classic 8" dob without goto would probably have been a better choice.

 

[redhat 2]

6 hours ago, midatlantic61 said:

150mm aperture for faint DSO?
hmmm...
How are your skies? Light pollution?
Feels you might have purchased the wrong scope for this task in the first place...
The classic 8" dob without goto would probably have been a better choice.

 

Good morning midatlantico61,

Thank you for your kind and prompt reply.

I can assure you I've given it a lot of consideration before the purchase, went for the local astro club meetings, star parties etc. Still, went for the second hand not to loose too much money in case my choice was wrong. Surprise, surprise, I'm very happy with that scope so far.

You see, not everyone has a luxury of living in villa under pristine skies of Azores. Some of us are living in 3-bed semi with limited storage, on the outskirts of light polluted London, and are still trying to pursue their passion in life.

There are those small things in life that make you happy and I clearly stated that I am very happy and excited with what I've got and simply asked for the advice on the eyepiece, not on the telescope. It is my first 'serious' scope. Maybe in the future, when I'll get bored with my tiny 6" I'll get me something bigger and then good ep will be already there waiting.

Sadly, the first one to reply to my post was the one that crawled out of his nerdy cave in Azores just to criticise my rig, instead of answering my straightforward question.

I wish you all the best watching skies through your massive telescopes you are so proudly presenting on your profile picture, pal.

P.S. Feels like you, old sport might have purchased the wrong scope, as where you live clearly good pair of binoculars would probably have been a better choice.

 

Edited October 18, 2019 by redhat
more info

[happy-kat 5,638]

Hi

I've got a 130p mirror and on edge of town and for DSO use my 16mm the most, once I've located the area with the lowest powered eyepiece to look in.

I don't find looking for faint smudges helped by high magnification so I'm thinking 10mm or 11mm is too much magnification for your intent.

[happy-kat 5,638]

A faint grey smudge is I find less obvious when the faint light is over a bigger area like what adding magnification does.

[redhat 2]

34 minutes ago, happy-kat said:

Hi

I've got a 130p mirror and on edge of town and for DSO use my 16mm the most, once I've located the area with the lowest powered eyepiece to look in.

I don't find looking for faint smudges helped by high magnification so I'm thinking 10mm or 11mm is too much magnification for your intent.

Hello,

Thank you very much for your kind advise. May I ask which exactly 16mm eyepiece you are using?

[Mr Spock 6,828]

For me, in heavily light polluted skies, a higher magnification is better. This is due to the sky being brighter at lower magnifications. 

From my experience with my 235mm, a 22mm giving x106 shows far more extension on objects than a 42mm giving x56. This is due to the background being darker.

The 8.8mm you mention would give x85 and 0.96° field of view. That would easily fit the Pleiades and M42. Only M31 is bigger and you aren't going to fit that in anyway. I reckon that would be my choice.

 

[Louis D 3,246]

If you are having to deal with light polluted skies, I suggest getting a UHC or OIII filter to make seeing nebula easier.  Galaxies are going to be all but impossible to see except possibly for their cores (M31 comes to mind).

Higher powers will make globular clusters stand out better from the background as @Mr Spock suggests.

[Alan White 5,277]

A 150mm f5 is a great scope to own under UK skies,
in many on here's opinion quite a Goldilocks scope, just right.

I think the comment about DSO you had, has a some validity, but any scope in Urban UK sky condition suffers.
The 150mm just is a size that copes well and is very portable.
So much so I am now on my third one to complement my 10" Dobsonian.

As to EP, what have you got with the scope so far?
Possibly a 20/25mm and a 10mm?
Just replacing these with better quality ones in itself will help.

My personal preference in a 150 f5 is a 18-20mm then a 13-15mm and then a 8-6mm.
At present I am churning my EP collection (all TeeleVue) to have longer eye relief and fit a Dioptrx unit.
My eyes have changed a lot in past 3 years I am now 53.

In answer to the question 19mm Panoptic sits well with a 150p scope.

One thing to remember is that is you go to a 30mm+ under near London skies, the sky will be very grey as you will see the background LP.
Go somewhere even slightly darker skies and pow, darker sky.

The exit pupil at 2mm for DSO, not sure who told you that one.
I find that with dark adapted eyes 3-5mm Exit pupil works better for me looking for faint grey smudges.

As a final minor point, in forum playing nice, please even if you get a post you don't overly like,
please, please be nice and not get into arguments, this is not Cloudy Nights!

 

Edited October 18, 2019 by Alan White

[happy-kat 5,638]

It's a Maxvision 16mm not available new now but comes up second hand.

[Stu 29,822]

1 hour ago, Alan White said:

The exit pupil at 2mm for DSO, not sure who told you that one.
I find that with dark adapted eyes 3-5mm Exit pupil works better for me looking for faint grey smudges.

2mm is often quoted as giving best contrast on DSOs, but I do agree that, particularly with filtered views, larger does work well.

A 150mm scope is more than capable of showing some decent views of DSOs, particularly if you can get it to a dark site. I was observing with a 100mm peashooter under quite light polluted skies and a fairly full moon last night, and managed credible views of M27 and M57, plus the Double Cluster and M45.

One thing which remains unanswered is the level of light pollution which you have at home? This will make a difference regarding whether you would be able to enjoy the larger faint objects or not.

DSOs vary in size alot, so some indication of your preferences would also help. In some respects, a 24mm 68 degree would be good for filtered views of larger nebulae or unfiltered for open clusters such as the Double Cluster and M45. With a good dark sky, this may be worthwhile. Otherwise the suggestion of a 16mm may be a good middle ground. 3.2mm exit pupil and a 1.45 degree field of view would be very handy on a range of objects.

[Rob Sellent 852]

10 hours ago, redhat said:

advice on the eyepiece

Congratulations on the scope @redhat. I'd recommend a set containing focal lengths around either:

• 24mm, 12mm, 8mm, and a x2 Barlow. Or (as @Stuhas already suggested) swop the 24mm for a 16mm

Within reason, this will yield around 30x (star clusters and nebulae), 63x (most DSOs), 94x (small DSOs, Moon, planets), and 126x (moon, planets, small DSOs) and 188x (planets, Moon, double stars). As for brands, that'll depend on your wallet. The secondhand market might also be someting of interest.

[heliumstar 411]

12 hours ago, redhat said:

Good morning midatlantico61,

Thank you for your kind and prompt reply.

I can assure you I've given it a lot of consideration before the purchase, went for the local astro club meetings, star parties etc. Still, went for the second hand not to loose too much money in case my choice was wrong. Surprise, surprise, I'm very happy with that scope so far.

You see, not everyone has a luxury of living in villa under pristine skies of Azores. Some of us are living in 3-bed semi with limited storage, on the outskirts of light polluted London, and are still trying to pursue their passion in life.

There are those small things in life that make you happy and I clearly stated that I am very happy and excited with what I've got and simply asked for the advice on the eyepiece, not on the telescope. It is my first 'serious' scope. Maybe in the future, when I'll get bored with my tiny 6" I'll get me something bigger and then good ep will be already there waiting.

Sadly, the first one to reply to my post was the one that crawled out of his nerdy cave in Azores just to criticise my rig, instead of answering my straightforward question.

I wish you all the best watching skies through your massive telescopes you are so proudly presenting on your profile picture, pal.

P.S. Feels like you, old sport might have purchased the wrong scope, as where you live clearly good pair of binoculars would probably have been a better choice.

 

 

He's actually right in a way...

BUT

Your scope is perfect to get some EAA going and you will be able to see a lot with a simple entry level AA or ZWO camera with a 224 chip. You can even use it with 0.5x reducer attached to the camera.

As far as eyepieces are concerned. I would get Panoptic 24mm, 13mm Nagler and 2.5x Powermate. It'll hurt at the beginning but you will be set for life and this combination will work for many telescopes down the road as well