Jump to content

SkySurveyBanner.jpg.21855908fce40597655603b6c9af720d.jpg

So, why would you choose a refractor over a SCT?


Recommended Posts

2 minutes ago, ollypenrice said:

I've heard this argument using the term 'cells of turbulence.' The fewer turbulent cells your scope looks through, the less it is affected. I have no means of commenting on this since I've no useful experience.

Olly

This is the thing, this is all reasoning and theory, but how do you design an experiment to prove it?...it's beyond me .

  • Like 1
Link to comment
Share on other sites

1 minute ago, Lockie said:

This is the thing, this is all reasoning and theory, but how do you design an experiment to prove it?...it's beyond me .

You send me two instruments, an 8 inch TEC apochromat and an exquisitely figured 8 inch Newt, both F8. I test them. I report my findings. At the end of the test I return the Newt.

😁lly

  • Haha 12
Link to comment
Share on other sites

6 hours ago, CraigT82 said:

If you look through a 4" F8 scope and an 8" F4 scope , you're looking through the same sized patch of atmosphere.

No you're not. You're looking at a parallel beam of light from a distant star that is either 4 inches or 8 inches wide.

  • Like 3
Link to comment
Share on other sites

9 minutes ago, Ags said:

No you're not. You're looking at a parallel beam of light from a distant star that is either 4 inches or 8 inches wide.

TBH as I was writing that I thought I was probably wrong, but whatever... I still dont believe the whole 'cells of turbulence' reason for smaller apertures cutting through seeing

  • Like 1
Link to comment
Share on other sites

6 hours ago, CraigT82 said:

Edit:  just thought... If the frac is of a much longer f ratio than the reflectors, the depth of focus will be greater and the wavefront disturbances caused by turbulent seeing would be less visible at the eyepiece?

I read an article recently (with some pretty in depth analysis which I didn’t understand) which concluded that for a given aperture, the focal ratio makes no difference to how it is affected by seeing. It was primarily about aperture. I need to see if I can find the article now! 
 

Edit: Found the article https://www.fpi-protostar.com/bgreer/seeing.htm

Re-reading the article, it actually says that longer focal ratio scopes might sometimes perform better in poor seeing than their shorter focal ratio counterparts, but not because of increased depth of focus. 

Edited by RobertI
  • Like 1
Link to comment
Share on other sites

I would love to put my two cents in, the OP's question could not have come at a better time, considering I just got my first refractor. I have had the good fortune of owning many scopes but, they were always reflectors of different types and sizes, bigger and less expensive has always been the deciding factor for me. My most recent has been a SW 150 Mak which has proven to be a very capable planetary/lunar scope but, it sure has its limitations. Having never owned a refractor short of a 60mm toy as a child, I have become so curious about giving a good refractor a try. Just hours ago I got my first decent frac, a 115mm Orion Eon triplet with 3" focuser, the minute I opened the case and held it, it was love at first sight, I was elated, it is beautiful and the sky was clear!. I set the scope out to cool, I can honestly say I have been missing out all these years, handling a refractor is so intuitive.  Never have I put a scope out for first light and everything was just perfect, I thought my mak was, I didn't know better. My mak just cannot bring stars to focus as quickly and perfectly as this frac can, snap to, perfect points looking like tiny orbs, the tightest points I have ever observed.

Don't get me wrong, I have had many memorable sessions with all my scopes but, I always wondered if I was missing something. Sometimes other scopes required too much fussing about to get them to work to their potential, time taken away from observing. Once my Eon reached temperature I immediately put in my most powerful Morpheus and did a star test, absolute perfect concentric rings on both sides of focus, identical pattern on either side, I never thought i'd be so overjoyed looking at an out of focus star. Next up was the moon, just razor sharp and, not the slightest hint of color around the edges, I tried to find it, tried all my eyepieces, no color fringing. Aside from the optics which seem to be great, I was struck by the FOV and contrast, only in my dob with a Zambuto mirror have I seen such a pleasant sight. To make things short, the clouds rolled in, leaving me with just under an hour for first light but, that's all it took for me to become a total convert. I have seen many scopes come and go, hoping each would be the lifelong scope, I think I found it. What a joy to use this frac is, I feel like a total noob all over again and its so exciting.

Edited by Sunshine
  • Like 12
  • Thanks 1
Link to comment
Share on other sites

3 hours ago, Sunshine said:

I would love to put my two cents in, the OP's question could not have come at a better time, considering I just got my first refractor. I have had the good fortune of owning many scopes but, they were always reflectors of different types and sizes, bigger and less expensive has always been the deciding factor for me. My most recent has been a SW 150 Mak which has proven to be a very capable planetary/lunar scope but, it sure has its limitations. Having never owned a refractor short of a 60mm toy as a child, I have become so curious about giving a good refractor a try. Just hours ago I got my first decent frac, a 115mm Orion Eon triplet with 3" focuser, the minute I opened the case and held it, it was love at first sight, I was elated, it is beautiful and the sky was clear!. I set the scope out to cool, I can honestly say I have been missing out all these years, handling a refractor is so intuitive, never have I put a scope out for first light and everything was just perfect, I thought my mak was, I didn't know better. My mak just cannot bring stars to focus as quickly and perfectly as this frac can, snap to, perfect points looking like tiny orbs, the tightest points I have ever observed.

Don't get me wrong, I have had many memorable sessions with all my scopes but, I always wondered if I was missing something. Sometimes other scopes required too much fussing about to get them to work to their potential, time taken away from observing. Once my Eon reached temperature I immediately put in my most powerful Morpheus and did a star test, absolute perfect concentric rings on both sides of focus, identical pattern on either side, I never thought id be so overjoyed looking at an out of focus star. Next up was the moon, just razor sharp and, mot the slightest hint of color around the edges, I tried to find it, tried all my eyepieces, no color fringing. Aside from the optics which seem to be great, I was struck by the FOV and contrast, only in my dob with a Zambuto mirror have I seen such a pleasant sight. To make things short, the clouds rolled in, leaving me with just under an hour for first light but, that's all it took for me to become a total convert, I have seen many scopes come and go, hoping each would be the lifelong scope, I think I found it, what a joy to use this frac is, I feel like a total noob all over again and its so exciting.

This kind of sums it all up really. Especially the "love at first sight" comment.

  • Like 1
  • Thanks 1
Link to comment
Share on other sites

2 hours ago, mikeDnight said:
6 hours ago, Sunshine said:

 

This kind of sums it all up really. Especially the "love at first sight" comment.

I notice you have a Tak 100, that must be a real gem of a scope, I couldn’t be happier about my first refractor, feel like I found a soul mate.

F343E35E-78EF-45FD-A8F3-EC353FDFAE6C.jpeg

Edited by Sunshine
  • Like 4
  • Thanks 1
Link to comment
Share on other sites

6 hours ago, Sunshine said:

I would love to put my two cents in, the OP's question could not have come at a better time, considering I just got my first refractor. I have had the good fortune of owning many scopes but, they were always reflectors of different types and sizes, bigger and less expensive has always been the deciding factor for me. My most recent has been a SW 150 Mak which has proven to be a very capable planetary/lunar scope but, it sure has its limitations. Having never owned a refractor short of a 60mm toy as a child, I have become so curious about giving a good refractor a try. Just hours ago I got my first decent frac, a 115mm Orion Eon triplet with 3" focuser, the minute I opened the case and held it, it was love at first sight, I was elated, it is beautiful and the sky was clear!. I set the scope out to cool, I can honestly say I have been missing out all these years, handling a refractor is so intuitive.  Never have I put a scope out for first light and everything was just perfect, I thought my mak was, I didn't know better. My mak just cannot bring stars to focus as quickly and perfectly as this frac can, snap to, perfect points looking like tiny orbs, the tightest points I have ever observed.

Don't get me wrong, I have had many memorable sessions with all my scopes but, I always wondered if I was missing something. Sometimes other scopes required too much fussing about to get them to work to their potential, time taken away from observing. Once my Eon reached temperature I immediately put in my most powerful Morpheus and did a star test, absolute perfect concentric rings on both sides of focus, identical pattern on either side, I never thought i'd be so overjoyed looking at an out of focus star. Next up was the moon, just razor sharp and, not the slightest hint of color around the edges, I tried to find it, tried all my eyepieces, no color fringing. Aside from the optics which seem to be great, I was struck by the FOV and contrast, only in my dob with a Zambuto mirror have I seen such a pleasant sight. To make things short, the clouds rolled in, leaving me with just under an hour for first light but, that's all it took for me to become a total convert. I have seen many scopes come and go, hoping each would be the lifelong scope, I think I found it, what a joy to use this frac is, I feel like a total noob all over again and its so exciting.

By jove I think he's got it 😁😁👍👍

Couldn't have put it better myself. Simplicity, ease of use, grab and go but most importantly aesthetically beautiful views. I've had a range of scopes, over 50 in all I think. I have enjoyed the SCTs and Maks I have had, and do like my current Mewlon 210 but even the Mewlon doesn't have the same pin point stars that you get with a good refractor.

The Vixen Fluorite I've recently acquired is a prime example of how enjoyable the views are, viewing the Double Cluster the other night, even under quite light polluted skies was breath taking, the tiny pin point stars at the threshold of visibility are wonderful to view. Tighter doubles may be resolve able in a larger aperture, but I confess my enjoyment comes from viewing these objects in a refractors. I do frequently consider getting a 130 or 140mm sponsor for these very reasons.

  • Like 5
  • Haha 1
Link to comment
Share on other sites

14 minutes ago, Stu said:

By jove I think he's got it 😁😁👍👍

Couldn't have put it better myself. Simplicity, ease of use, grab and go but most importantly aesthetically beautiful views. I've had a range of scopes, over 50 in all I think. I have enjoyed the SCTs and Maks I have had, and do like my current Mewlon 210 but even the Mewlon doesn't have the same pin point stars that you get with a good refractor.

The Vixen Fluorite I've recently acquired is a prime example of how enjoyable the views are, viewing the Double Cluster the other night, even under quite light polluted skies was breath taking, the tiny pin point stars at the threshold of visibility are wonderful to view. Tighter doubles may be resolve able in a larger aperture, but I confess my enjoyment comes from viewing these objects in a refractors. I do frequently consider getting a 130 or 140mm sponsor for these very reasons.

Thanks, i cant explain it, for so many years i have been single minded regarding bigger bigger bigger for less money per inch of aperture. Using this triplet eon last night, as short as the session was, it was like i was discovering the hobby again. Its beauty and simplicity both aesthetic and, functional, was something i had never experienced before. The wealth of creamy dark space around the moon, the moon etched into that space so razor sharp was gasp inducing. Training it on the nearest bright star ( so excited i didn't even bother to check which star it was) i was struck by the most perfect concentric patterns i ever saw, both sides of focus. The star itself in focus was as tight and defined as the period at the end of this sentence. Wow, i feel like i am on a new journey of discovery, i cant wait for my next session, i feel like a caged rat right now with the bad weather here. Soon i will post more images in the refractor forum.

Edited by Sunshine
  • Like 6
Link to comment
Share on other sites

19 minutes ago, mikeDnight said:

When its cloudy and raining you'll find yourself just sitting and staring at your beautiful refractor, with a slightly increased heart rate. :wub:

Thanks you Sir! i have posted in another thread with some nicer images, link is below.

 

  • Like 1
Link to comment
Share on other sites

What's not to like about refractors?

As you can see from my sig, I have two of them. 70mm is ultraportable and can be taken anywhere on a whim, used for white solar and Ha and will travel by airplane. 100mm can be out in a whisker and is also awesome for solar. Also a good travel scope when travelling by car.

Aperture rules but refractors up to 100mm are really convenient. It is unfair to compare apples and oranges but the views from my Tak are sometimes breathtaking. Just try Double Cluster in a 100mm refractor...aperture does not always rule, there are exceptions.

It also depends on your viewing habits and circumstances. But refractors can do double duty (solar included) the best and that has greatly expanded my targets and enjoyment of the hobby. I think I have spent more time doing H-alpha with the Quark in my refractors than hunting faint DSOs. Literally every clear morning pre-work is an opportunity, waiting for the tea to brew...

Refractors are great for backyard guerrilla astronomy, looking for the holes in the clouds and short opportunities to to observe the Moon, the planets, whatever. From what I remember UK skies are just like that, most of the time.

Edited by BGazing
  • Like 9
Link to comment
Share on other sites

12 hours ago, Sunshine said:

I would love to put my two cents in, the OP's question could not have come at a better time, considering I just got my first refractor. I have had the good fortune of owning many scopes but, they were always reflectors of different types and sizes, bigger and less expensive has always been the deciding factor for me. My most recent has been a SW 150 Mak which has proven to be a very capable planetary/lunar scope but, it sure has its limitations. Having never owned a refractor short of a 60mm toy as a child, I have become so curious about giving a good refractor a try. Just hours ago I got my first decent frac, a 115mm Orion Eon triplet with 3" focuser, the minute I opened the case and held it, it was love at first sight, I was elated, it is beautiful and the sky was clear!. I set the scope out to cool, I can honestly say I have been missing out all these years, handling a refractor is so intuitive.  Never have I put a scope out for first light and everything was just perfect, I thought my mak was, I didn't know better. My mak just cannot bring stars to focus as quickly and perfectly as this frac can, snap to, perfect points looking like tiny orbs, the tightest points I have ever observed.

Don't get me wrong, I have had many memorable sessions with all my scopes but, I always wondered if I was missing something. Sometimes other scopes required too much fussing about to get them to work to their potential, time taken away from observing. Once my Eon reached temperature I immediately put in my most powerful Morpheus and did a star test, absolute perfect concentric rings on both sides of focus, identical pattern on either side, I never thought i'd be so overjoyed looking at an out of focus star. Next up was the moon, just razor sharp and, not the slightest hint of color around the edges, I tried to find it, tried all my eyepieces, no color fringing. Aside from the optics which seem to be great, I was struck by the FOV and contrast, only in my dob with a Zambuto mirror have I seen such a pleasant sight. To make things short, the clouds rolled in, leaving me with just under an hour for first light but, that's all it took for me to become a total convert. I have seen many scopes come and go, hoping each would be the lifelong scope, I think I found it. What a joy to use this frac is, I feel like a total noob all over again and its so exciting.

That was so brilliant to read, I'm really happy for you :) 

  • Like 2
  • Thanks 1
Link to comment
Share on other sites

Sounds like the OP has an exceptional C5, and perhaps a less than average 80ED. Of the two SCTs I’ve owned (C6 and C8 Edge) even perfectly collimated, they couldn’t replicate the tightness of stars through a good refractor, though the Edge wasn’t far off. It does seem, however, as if a very small percentage of SCTs do have outstanding optics, and if you have one you should never be tempted to sell. Can imagine a top performing C5 is a great all-round scope.

  • Like 3
Link to comment
Share on other sites

On 03/03/2020 at 21:40, Highburymark said:

Sounds like the OP has an exceptional C5

Yes, I think I very much think this now and feel the need to test it side by side with my ED80. Both with and without the reducer on the C5, perhaps add in the 6" classic cas too. Not a terrible problem to have... :smiley:

Link to comment
Share on other sites

  • 1 month later...
On 03/03/2020 at 09:59, Sunshine said:

I would love to put my two cents in, the OP's question could not have come at a better time, considering I just got my first refractor. I have had the good fortune of owning many scopes but, they were always reflectors of different types and sizes, bigger and less expensive has always been the deciding factor for me. My most recent has been a SW 150 Mak which has proven to be a very capable planetary/lunar scope but, it sure has its limitations. Having never owned a refractor short of a 60mm toy as a child, I have become so curious about giving a good refractor a try. Just hours ago I got my first decent frac, a 115mm Orion Eon triplet with 3" focuser, the minute I opened the case and held it, it was love at first sight, I was elated, it is beautiful and the sky was clear!. I set the scope out to cool, I can honestly say I have been missing out all these years, handling a refractor is so intuitive.  Never have I put a scope out for first light and everything was just perfect, I thought my mak was, I didn't know better. My mak just cannot bring stars to focus as quickly and perfectly as this frac can, snap to, perfect points looking like tiny orbs, the tightest points I have ever observed.

Don't get me wrong, I have had many memorable sessions with all my scopes but, I always wondered if I was missing something. Sometimes other scopes required too much fussing about to get them to work to their potential, time taken away from observing. Once my Eon reached temperature I immediately put in my most powerful Morpheus and did a star test, absolute perfect concentric rings on both sides of focus, identical pattern on either side, I never thought i'd be so overjoyed looking at an out of focus star. Next up was the moon, just razor sharp and, not the slightest hint of color around the edges, I tried to find it, tried all my eyepieces, no color fringing. Aside from the optics which seem to be great, I was struck by the FOV and contrast, only in my dob with a Zambuto mirror have I seen such a pleasant sight. To make things short, the clouds rolled in, leaving me with just under an hour for first light but, that's all it took for me to become a total convert. I have seen many scopes come and go, hoping each would be the lifelong scope, I think I found it. What a joy to use this frac is, I feel like a total noob all over again and its so exciting.

This description makes me want a APO triplet. The more I read on the forums refractors seem to be almost frustration free, giving you more time to enjoy the stars. But I want a 7 or 8 inch one :)). 

  • Like 1
Link to comment
Share on other sites

25 minutes ago, dan_adi said:

This description makes me want a APO triplet. The more I read on the forums refractors seem to be almost frustration free, giving you more time to enjoy the stars. But I want a 7 or 8 inch one :)). 

Oh boy, a 7/8 inch apo, that’s a whole new level of bankruptcy right there.

  • Like 1
Link to comment
Share on other sites

On 18/04/2020 at 16:21, Sunshine said:

Oh boy, a 7/8 inch apo, that’s a whole new level of bankruptcy right there.

I know, they are expensive. They way I think is, life is short, I work hard, I can make it happen :). For me amateur astronomy is a way to relax, it’s fun, keeps me learning something new and cool about the universe. I need a change of scenary after a full days work in the intensive care ward. I wish I had more time for astronomy but unfortunately I also need to sleep. But after the minimum experience I have with amateur astronomy (just a merely 3 years) I am getting the refractor bug. If everything will go according to plan maybe in 3 months I will do a review of either LZOS 175 apo or CFF 185 apo (fingers crossed)

  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.