Reflector vs Refractors

[mikeDnight]

22 minutes ago, Tommohawk said:

 

Just a couple of thoughts to add.

Aperture rules but only in terms of resolution. For planetary imaging you need plenty of aperture, but resolution is not so critical for deep sky stuff. 

So far as "light grasp" goes a 60mm F4 is the same as a 300mm F4. The 60mm will have a wider field of view and is better for large (is large angular size) targets. 

 

 

Im not following your point regarding the 300mm vs 60mm. As far as light grasp goes, a 300mm reflector gathers considerably more light than a 60mm refractor and will go far deeper and show far more detail, including colour in many deep sky targets because it has more than 25X the surface area of the 60mm. Apart from giving beautiful rich star fields and pleasing lunar views, i really cant see any advantage of a 60mm scope over a 300mm. It's resolution is too limited for a planetary advantage and its light grasp would not be enough to show the majority of DSO's well.

[dweller25]

14 hours ago, Dannomiss said:

This is so good. I was told this is a ncie place and what you guys have said and shared is so helpful 😁

So hypothetically speaking, if a newbie wanted a refractor as well, what would you recommend. Asking for a friend 😉

Oh - you want us to spend your money 😁

Well, you have a very capable 150mm Newt so what are your expectations from buying a refractor ?
 

To get brighter views with more resolution you will need a large refractor - perhaps as a minimum the Skywatcher ED120 ? BUT it will need a suitable mount so the price rapidly climbs.

A much cheaper option to improve on your 150mm Newt would be a 10” Dob.

 

 

[andrew s]

@Tommohawk what do you mean by "light grasp" as 60mm has much less light gathering capability (photons per second) than a 300mm. 

Regards Andrew 

Sorry just noticed others had made the same point.

Edited July 4, 2020 by andrew s

[DirkSteele]

Refractors can see space vampires. With a reflector you never see them coming! 😉

 

I could add to the debate seriously but both have positives and negatives which have already been covered. 
 

But I will leave you with this... Mirrors are for shaving!

(yes I am a refractor guy)

[CraigT82]

Mirrors are for science exploration and discovery.

Lenses are for pretty pictures!

 

[Alfian]

5 minutes ago, CraigT82 said:

Mirrors are for science exploration and discovery.

Lenses are for pretty pictures!

 

Ooooooo! I'll be surprised if you will get away with that!😉

[Stu]

51 minutes ago, mikeDnight said:

Im not following your point regarding the 300mm vs 60mm. As far as light grasp goes, a 300mm reflector gathers considerably more light than a 60mm refractor and will go far deeper and show far more detail, including colour in many deep sky targets because it has more than 25X the surface area of the 60mm. Apart from giving beautiful rich star fields and pleasing lunar views, i really cant see any advantage of a 60mm scope over a 300mm. It's resolution is too limited for a planetary advantage and its light grasp would not be enough to show the majority of DSO's well.

This is where conversations should be clear about whether they relate to imaging or visual. I assumed this was very much a visual thread, but the post above is about imaging.

There is some sense of the differences between a small frac and a large dob in this post I made a while back.

 

[DaveL59]

1 hour ago, dweller25 said:

Oh - you want us to spend your money 😁

Well, you have a very capable 150mm Newt so what are your expectations from buying a refractor ?
 

To get brighter views with more resolution you will need a large refractor - perhaps as a minimum the Skywatcher ED120 ? BUT it will need a suitable mount so the price rapidly climbs.

A much cheaper option to improve on your 150mm Newt would be a 10” Dob.

 

 

as OP has already said tho, he doesn't drive and would like something he can travel easier with so a big dob ain't gonna help at all.

In many ways a tripod is likely easier to carry along slung on a shoulder strap than a big boxy thing that's awkward to carry over distances, tho for a larger scope of course it'll be heavy especially once you add the mount and counterweights into the mix. In reality for a grab n go which is more likely the simplest solution, smaller refractor or perhaps a MAK, I expect he'd have to accept the limitations of a smaller aperture and maybe a tripod/mount that is capable enough, a good solid photo type and alt-az perhaps?

Edited July 4, 2020 by DaveL59

[RT65CB-SWL]

41 minutes ago, DirkSteele said:

But I will leave you with this... Mirrors are for shaving!

A few years ago at a public outreach event; Ms Josephine Public was looking down the tube of my ETX105; (before the 'remod'); 
...and applying her lipstick!!  

[DaveL59]

1 minute ago, Philip R said:

A few years ago at a public outreach event; Ms Josephine Public was looking down the tube of my ETX105; (before the 'remod'); 
...and applying her lipstick!!  

count yourself lucky she didn't decide to touch up the foundation and eye shadow too and leave little powdery debris all over the corrector  

[dweller25]

30 minutes ago, DaveL59 said:

as OP has already said tho, he doesn't drive and would like something he can travel easier with so a big dob ain't gonna help at all.

In many ways a tripod is likely easier to carry along slung on a shoulder strap than a big boxy thing that's awkward to carry over distances, tho for a larger scope of course it'll be heavy especially once you add the mount and counterweights into the mix. In reality for a grab n go which is more likely the simplest solution, smaller refractor or perhaps a MAK, I expect he'd have to accept the limitations of a smaller aperture and maybe a tripod/mount that is capable enough, a good solid photo type and alt-az perhaps?

Precisely - the current scope he has may well be the best option ?

[DaveL59]

except he's already said it's awkward to travel with...

[Stu]

Just now, dweller25 said:

Precisely - the current scope he has may well be the best option ?

Indeed. Don’t forget you can take these off their dob mounts and put them on something like an AZ5 head on a photo tripod for a more portable option.

[DaveL59]

are we not forgetting - travelling for work often involves carrying with you clothing, perhaps equipment. You're adding a 6-inch scope into that mix and not using a car for the journey. How likely is it that it'd get lugged along, more likely it'll be left behind because it becomes simply too much, even if dismounted off the dob base I'd think. I certainly wouldn't have been able to take something like that along on trips I used to make. Something like an ST80 yes, but a big scope no chance.

[wookie1965]

2 hours ago, dweller25 said:

Oh - you want us to spend your money 😁

Well, you have a very capable 150mm Newt so what are your expectations from buying a refractor ?
 

To get brighter views with more resolution you will need a large refractor - perhaps as a minimum the Skywatcher ED120 ? BUT it will need a suitable mount so the price rapidly climbs.

A much cheaper option to improve on your 150mm Newt would be a 10” Dob.

 

 

My first Scope was a skywatcher 150p and that is the only one I have ever seen 6 star's in the trapezium, I never saw it in my 8inch or with both of my refractors, saying that when I did see them I had a pristine night I've not had one that good since with the lamp outside my viewing position 😥

The 150 is a very capable scope.

[Paz]

Any choice of telescope involves trading off one thing for another, it certainly keeps things interesting!

[John]

2 hours ago, Alfian said:

Ooooooo! I'll be surprised if you will get away with that!😉

I sort of agree with it actually.

And I have 4 refractors and just reflector

[Alfian]

Isn't it good how threads like this really bring out the passionate enthusiasm that the good people on SGL have for astronomy. I have a liking for refractors but a view of the Leo triplet through a 22" truss dob (wow on both accounts) on an evening of less than ideal seeing left a lasting impression. Size does make a difference!  Getting the best out of what we have is a worthy goal in itself but its perhaps inevitable that we always want more.

[John]

11 minutes ago, Alfian said:

Isn't it good how threads like this really bring out the passionate enthusiasm that the good people on SGL have for astronomy. I have a liking for refractors but a view of the Leo triplet through a 22" truss dob (wow on both accounts) on an evening of less than ideal seeing left a lasting impression. Size does make a difference!  Getting the best out of what we have is a worthy goal in itself but its perhaps inevitable that we always want more.

Views with scopes of that aperture live with you for for a long time

I can still vividly recall M13 and M51 observed with a 20 inch at the SGL star party quite a few years ago now. Jaw dropping 

[ScouseSpaceCadet]

8 hours ago, mikeDnight said:

As you're located in Liverpool you could make yourself a member of Liverpool Astronomical Society. It's a great society with very enthusiastic members who would be more than willing to give you hands on experience with some great refractors. Obviously it would need to be after the lockdown has been lifted and the danger of Covid has been genuinely reduced, but you'd get a side by side experience with scopes of various kinds. Maksutov Cassegrains are seriously sweet scopes that can approach refractor performance at a fraction of the cost. A 127mm Maksutov is a very good scope, but much larger and they become quite heavy!

 

The LAS observatory is great to visit, but it's hit and miss if anyone bothers looking at your application to join or even takes an interest...

 

Re: refractors. You have a very capable telescope already. Get the most out of that before spending more dosh.

 

Edited July 4, 2020 by ScouseSpaceCadet

[Tenor Viol]

I've been an amateur astronomer since about 1970, but I've been 'away' from the practical side for over 25 years. There has been a big change in that time and the biggest is the availability of relatively inexpensive high quality refractors. 

Back when I started out, refractors were either very large (e.g. 5 or 6 inch objectives at f/12 or f/15) in club or university observatories, or they were 3 inch, generally in brass tubes and again at f/12 or more. They were the domain of people observing the Moon and planets. They were uncommon as they were expensive. 

People were more likely to have a 6 or 8 inch Newtonian, but it would be around f/8. These were more 'general purpose' in nature and could be used for some DSO as well as lunar and planetary.

Several things then happened: SCTs arrived providing much more compact 8" instruments, albeit at f/10. The other thing that happened was the Dobsonian. German equatorial mounts, which is what almost everything is mounted on, get to be very large / tall if you're talking an 8" f/8 Newtonian, or a 4" f/15 refractor. 

Suddenly people were buying 10, 12, 15 inch 'fast' Newtonians at f/6.3, f/5 or faster. These are much shorter and the Dobsonian mount is much less cumbersome. Many more were now into visual DSO.

By the time I dropped out of regular observing in the 90s, motorised drives were becoming more common (e.g. Vixen). 

Since then, two technology changes have been key: the arrival of digital photography; computer controlled mass-production of optics, including lenses. The latter has made high quality short-focus (and therefore easier to manage) refractors available, and the former has led to an explosion of interest in astrophotography. 

There is no 'right' answer to most questions, only the set of compromises you are happy with. In general, you can get more light grasp i.e. aperture for your buck by going the reflector route, but it leads to very bulky instruments. You generally get better contrast with refractors because of the absence of an obstruction in the light path, but if you want image scale then the long focal ratio instruments are very long.

The observatory I had access to as a youngster housed a classic Victorian f/15 5" refractor - the views of the Moon could be stunning in good conditions. But a star cluster in good skies through a 10 inch f/4.8 Newtonian is also a good view. Horses for courses....

[jetstream]

I have a 24" dob, 15" dob and a TSA120. The TSA 120 offers technically "perfect" views and has "unlimited" magnification performance.Its lunar views are impressive- for its aperture.

The 15" which stays assembled and takes 5 minutes to wheel out and collimate is my goto scope and can give lunar views over 700x razor sharp. The difference in detail between the 2 scopes is big. It takes me over 20 min to haul the EQ6 out, level it, get the TSA on it and align and is harder to put away. the 15" has excellent optics.

@Dannomiss the H150 will give views that are hard to beat- I have a 90mm APO that gets left in the sea can while the H130 is out observing. It sounds like your main concern is portability. I would look for a short fast refractor-triplet APO in the 90mm-105mm range and not expect it to give more detail on the moon or show more DSO than the H150. It will most likely allow higher mag lunar/planetary views however. Just a thought.

[cloudsweeper]

3 hours ago, John said:

I sort of agree with it actually.

And I have 4 refractors and just reflector

Says a lot John!  I've had 1 Mak, 1 SCT, 2 Reflectors, and 5 fracs!  Current audit: 1 SCT, 1 Dob, 3 fracs.

Having a decent selection means you have all bases covered.

Doug.

[michael.h.f.wilkinson]

7 hours ago, CraigT82 said:

Mirrors are for science exploration and discovery.

Lenses are for pretty pictures!

 

Nope, mirrors can get pretty pictures as well

[Barry-W-Fenner]

I now have the joy of owning 3 reflectors and am a big fan of them. I haven't had the opportunity to try a refractor and k ow very little about them so can't comment. However I would certainly love to look at some doubles through a refractor and experiance the views they have to offer. 
 

IMO any opportunity you get to take in the wonderful views of our universe should be jumped on! Be it via reflector or refractor 😀