Reflector vs Refractors

[mikeDnight]

9 minutes ago, Victor Boesen said:

I would be paranoid to even touch the dew-shield not to place a mark on that lens! I really hope you don't lick it😅

Don't worry! The handbook specifically says "No licking!" as it voids the warranty.  😂

[andrew s]

5 minutes ago, mikeDnight said:

 Looking at the lens below, don't you feel the need to lick it, or am I just weird?

No, yes.

Regards Andrew 

[Alan White]

5 minutes ago, mikeDnight said:

 am I just weird?

Short answer....... YES 😉  but in a good way.
 

5 minutes ago, mikeDnight said:

But would its mirror make your mouth water and your heart skip a beat? Looking at the lens below, don't you feel the need to lick it, or am I just weird?

A new way of lens cleaning, but just don't do it on a very cold frosty night, just in case you get stuck.
Now how would that look in A&E?

[Alien 13]

My 90mm Mak is very lickable, my Labrador took a swipe at it with her tongue during unboxing...

Alan

[Dannomiss]

28 minutes ago, CraigT82 said:

little ED 66 or 72mm frac

Very nice. I like that. 👌

I didn't realise until the other day that the heritage actually came off the dobsonian base 😂 doh

[Dannomiss]

About the licking- it's off topic and that's a different forum 😂

[paulastro]

26 minutes ago, mikeDnight said:

Reflectors can offer good resolution and light grasp at a price that's within the grasp of any serious observer, especially if you want to do serious deep sky study. Reflectors also make great lunar and planetary scopes, and because of the greater resolution of a relatively large aperture, they can reveal great detail. The down side is that they need regular colimation adjustments, suffer from spider diffraction which is every bit as damaging to definition and contrast as CA, and they suffer from coma. Larger apertures can take a long time to attain thermal stability and they can be cumbersom.

Refractors can often provide higher definition, higher magnification  (100X per inch and more) and wider field views than the equivalent aperture reflector. In fact it has long been acknowledged that a smaller aperture refractor of high quality can often outperform a reflector of significantly greater aperture. For instance, I have on many occasions witnessed a 4" refractor outperform an 8" reflector, and a 5" refractor a 10" reflector. On top of that, a refractor can work at optimum in just a few minutes after being taken from a warm house into a cold winter night. The hardly ever have colimation issues and have piercingly sharp star images with no diffraction spikes. The old CA issues are all but gone in a modern ED or Apo refractor, but there's nothing you can do to eliminate the destructive effects of spider diffraction unless you use an optical window or Maksutov corrector, and even then the reflector user has to contend with central obstruction which subtracts light from the Airy disc and adds it to the diffraction rings.

Just incase you're in any doubt, I like reflectors, but I love refractors! 

 

Mike, I think my memory is playing tricks on me again.  I was sure you have told me more than once that anyone who uses a reflector must be a right plonker. 🙂

 

[jock1958]

12 minutes ago, mikeDnight said:

But would its mirror make your mouth water and your heart skip a beat? Looking at the lens below, don't you feel the need to lick it, or am I just weird?

You’ve got me drooling now @mikeDnight nothing better than the hallowed 100DZ with retractable dew shield!! 

[cloudsweeper]

All this passion!  But which telescope do you actually cuddle in use.............Yes, the Dobsonian reflector!  😉

Doug.

[DaveL59]

1 minute ago, cloudsweeper said:

All this passion!  But which telescope do you actually cuddle in use.............Yes, the Dobsonian reflector!  😉

Doug.

is that to stop it falling over in a breeze?  

(sorry Stu - a bad memory there perhaps)

[Victor Boesen]

Just now, Dannomiss said:

About the licking- it's off topic and that's a different forum 😂

Back to your original question. I was originally skeptic about the small refractor when I purchased it but I was surprised. I really think you should try one yourself to observe the difference between you current telescope and a refractor. It's not like the view is day and night different but you notice that the stars don't have diffraction spikes but airy disks instead and the star fields look a little cleaner. A refractor is often also more stable on planets because of the smaller aperture and therefore you are looking through less atmosphere. Some, including myself, find this very comfortable and relaxing compared to a more wobbly view through a dobsonian with larger aperture. With that said, the patient guy at a star party with a large dob will most likely always go to bed having seen more detail on planets than the ones with a small frac but that moment of crisp details perhaps only lasts a couple of seconds.

[JeremyS]

31 minutes ago, mikeDnight said:

But would its mirror make your mouth water and your heart skip a beat? Looking at the lens below, don't you feel the need to lick it, or am I just weird?

Mike you so nearly had me licking the screen of my iPad then that I had to go a retract the dew cap on my Tak TSA 120. 
Feeling better now.

[Dannomiss]

31 minutes ago, Victor Boesen said:

Back to your original question. I was originally skeptic about the small refractor when I purchased it but I was surprised. I really think you should try one yourself to observe the difference between you current telescope and a refractor. It's not like the view is day and night different but you notice that the stars don't have diffraction spikes but airy disks instead and the star fields look a little cleaner. A refractor is often also more stable on planets because of the smaller aperture and therefore you are looking through less atmosphere. Some, including myself, find this very comfortable and relaxing compared to a more wobbly view through a dobsonian with larger aperture. With that said, the patient guy at a star party with a large dob will most likely always go to bed having seen more detail on planets than the ones with a small frac but that moment of crisp details perhaps only lasts a couple of seconds.

I would love one mainly for portability. My heritage 150p is very portable. But as I don't drive obviously its awkward. Not heavy just awkward. I'm away a lot for work and where I work there is plenty of dark sky... So a refractor for that reason is also tempting. Need to get more out of my Reflector before I also get a refractor, but the differenece has intrigued me

[wookie1965]

The biggest scope I've looked through is a 22" at M51 and what a sight it was. I had a lovely 8" reflector which I should never of parted with it was very good at getting fainter objects.

I only ever used it at meets so 2/3  times a year good for deep sky.

I have two refractors a Tal 100rs and s Meade 127 5"  these you can get out even if the sky not that clever these punch through. Double stars, multiple stars and cluster's even from light polluted sky's is why I have them plus planets look like marbles and stars look pin sharp.

Edited July 3, 2020 by wookie1965

[Dannomiss]

5 minutes ago, wookie1965 said:

The biggest scope I've looked through is a 22" at M51 and what a site it was. I had a lovely 8" reflector which I should never of parted with it was very good at getting fainter objects.

I only ever used it at meets so 2/3  times a year good for deep sky.

I have two refractors a Tal 100rs and s Meade 127 5"  these you can get out even if the sky not that clever these punch through. Double stars, multiple stars and cluster's even from light polluted sky's is why I have them plus planets look like marbles and stars look pin sharp.

Stop it. The temptation is getting harder to resist 😂

[Stu]

18 minutes ago, andrew s said:

However, you could get a reflector with an aperture that would put its Airy disk and first ring completely inside the Airy disk of a refractor for less money.

Regards Andrew 

Perhaps in the Atacama desert, but unlikely in U.K. seeing conditions!

I love refractors because I love the aesthetics of the views, particularly the star shapes; they are what makes my little heart sing. I enjoy looking through Newtonians and they are certainly the thing to have for most DSOs (except the very biggest ones). Often though the views are more affected by seeing conditions (to my first point above), and that I find much more distracting when observing. This particular applies to double stars and often planets, particularly when they are low like they are currently. Yes the dob will likely show more but if you are not enjoying the views, then.....

I do enjoy the different perspective you get through say, a big dob and a widefield refractor. The dob giving up close and personal, higher resolution views, and the refractor the wider perspective. I have often put an SCT or Mak side by side with a refractor for similar reasons.

I aspire to a top end 130mm apo at some point in time, when funds allow. Ultimately I think that, my Tak FC100DC and a 12 or 14” in dob would be plenty.....he says 🤣🤣

[Captain Scarlet]

I spend an amount of time in two different places, one rather light polluted and one most definitely not (though usually quite cloud-polluted  ).

The telescope I preferentially reach for in each place is completely different. In the Bortle 6-7 place, I instinctively reach for my high-quality 105mm refractor, for exactly the reasons @Stu mentioned.

In my dark place, I first go for my 12” newt, for the fact I can see spiral detail in M51, cloud lanes in M31 and so much depth in M13. I’d go for bigger if I had it...

Horses for courses.

M

[andrew s]

20 minutes ago, Stu said:

Perhaps in the Atacama desert, but unlikely in U.K. seeing conditions!

Maybe for visual but for imaging you can use much shorter exposures with the larger aperture and more effectively stop the seeing. Getting lucky scales as aperture squared.

No need for a desert just excellent collimation. 😉😄

Regards Andrew 

[mikeDnight]

10 hours ago, Dannomiss said:

Stop it. The temptation is getting harder to resist 😂

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!

 

[Stu]

10 hours ago, andrew s said:

Maybe for visual but for imaging you can use much shorter exposures with the larger aperture and more effectively stop the seeing. Getting lucky scales as aperture squared.

No need for a desert just excellent collimation. 😉😄

Regards Andrew 

Yep, but I’m visual only so that doesn’t help me! Explains why there are many and varied preferences I guess 🤪

[andrew s]

51 minutes ago, Stu said:

Yep, but I’m visual only so that doesn’t help me! Explains why there are many and varied preferences I guess 🤪

Yes indeed. There are always lots of hidden assumptions in these discussions.

Visual v imaging, sky quality, telescope quality and or cost, deep sky or solar system, portable or permanent.

Amazing any ever agrees.

Regards Andrew 

[Dannomiss]

13 hours ago, Victor Boesen said:

Back to your original question. I was originally skeptic about the small refractor when I purchased it but I was surprised. I really think you should try one yourself to observe the difference between you current telescope and a refractor. It's not like the view is day and night different but you notice that the stars don't have diffraction spikes but airy disks instead and the star fields look a little cleaner. A refractor is often also more stable on planets because of the smaller aperture and therefore you are looking through less atmosphere. Some, including myself, find this very comfortable and relaxing compared to a more wobbly view through a dobsonian with larger aperture. With that said, the patient guy at a star party with a large dob will most likely always go to bed having seen more detail on planets than the ones with a small frac but that moment of crisp details perhaps only lasts a couple of seconds.

I would love one mainly for portability. My heritage 150p is very portable. But as I don't drive obviously its awkward. Not heavy just awkward. I'm away a lot for work and where I work there is plenty of dark sky... So a refractor for that reason is also tempting. Need to get more out of my Reflector before I also get a refractor, but the differenece has intrigued me

[andrew s]

5 minutes ago, Dannomiss said:

I would love one mainly for portability. My heritage 150p is very portable. But as I don't drive obviously its awkward. Not heavy just awkward. I'm away a lot for work and where I work there is plenty of dark sky... So a refractor for that reason is also tempting. Need to get more out of my Reflector before I also get a refractor, but the differenece has intrigued me

Don't  forget the refractor is just that. It will need a mount and tripod. Plus with the eyepiece is at the lower end you need a taller mount/tripod. All in all will it be more portable that the Heritage 150?

Regards Andrew 

Edited July 4, 2020 by andrew s

[Tommohawk]

 

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. 

A larger scope weighs more and needs a bigger mount and if not well managed may give worse results than a smaller one. 

There are design  limits on how small a reflector can go - the secondary causes more obstruction and the coma corrector intrudes more in the light path. 

So. It would be great to have one scope for all, but in practice a small refractor or camera lens is probably best for wide field, although these days if you don't have a widefield it's easy to do mosaics. A big reflector or Schmidt Cass is best for planetary, and in between you pays your money and takes your choice. 

I've owned a fair few scopes now and my view is that for an all rounder a Newtonian is a good buy, especially if on a budget. A cheap Newtonian performs better than a cheap refractor in my view, especially for astrophotography. 

Well.. that's my view anyhow, other views are available!

[Timebandit]

31 minutes ago, Dannomiss said:

I would love one mainly for portability. My heritage 150p is very portable. But as I don't drive obviously its awkward. Not heavy just awkward. I'm away a lot for work and where I work there is plenty of dark sky... So a refractor for that reason is also tempting. Need to get more out of my Reflector before I also get a refractor, but the differenece has intrigued me

 

Don't forget you can still get a lot of enjoyment with mark one eyeballs under real Dark Sky's.

Also a great grab and go and very portable option is a pair of binoculars. A good pair of binoculars are also very portable and effective under dark Sky's.

So the list is increasing , reflector, refractor and binos ☺

Horses for course's👍