Jump to content

Banner.jpg.39bf5bb2e6bf87794d3e2a4b88f26f1b.jpg

Refractor For Purely Visual Astronomy?


Recommended Posts

2 minutes ago, John said:

I'm sure that these 80mm refractors are lovely things but the original posters scope should show all that they do and more besides and catch challenging stuff like Neptune's moon Triton which is simply beyond a 4 inch refractor no matter how good it's optics are.

Having a small refractor AND a medium aperture scope is a great way to go though :icon_biggrin:

 

 

 

Would you say my Sky-Watcher 200P is a medium aperture scope? 

Link to comment
Share on other sites

10 minutes ago, John said:

I'm sure that these 80mm refractors are lovely things but the original posters scope should show all that they do and more besides and catch challenging stuff like Neptune's moon Triton which is simply beyond a 4 inch refractor no matter how good it's optics are.

Having a small refractor AND a medium aperture scope is a great way to go though :icon_biggrin:

 

 

 

Agree. Modest light bucket and a grab and go set-up (frac) has made it so I can observe on the hoof but also plan proper sessions when the conditions allow for more deep sky observing. Not to mention WL solar viewing too. 

The more I observe though the more I am starting to gravitate to a more specific field, i.e. planetary!
 

 

Edited by IB20
  • Like 1
Link to comment
Share on other sites

2 minutes ago, IB20 said:

Agree. Modest light bucket and a grab and go set-up (frac) has made it so I can observe on the hoof but also plan proper sessions when the conditions to allow for more deep sky observing. Not to mention WL solar viewing too. 

The more I observe though the more I am starting to gravitate to a more specific field, i.e. planetary!
 

 

The funny thing is that I'm moving away from DSO's and more towards planet viewing. I'm still intrigued by the ScopeTech Maxi... 

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

18 minutes ago, Ian McCallum said:

Would you say my Sky-Watcher 200P is a medium aperture scope? 

Yes - that's just the sort of scope that I meant.

Personally I'd go for a 100mm refractor (or more) over an 80mm or a 90mm. I've owned nice 80's and 90's but found that they did not quite show enough to hold my interest for long. Something like an ED 102mm F/7 for versatility as I think was suggested earlier in this thread.

That's just my preferences though. Yours are what matter much more in this thread :smiley:

 

 

 

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

When I was looking for a refractor, weight was one of the most important factors for me. I don’t know what the lightest rig is for the 102ed but lots of people recommended stability. An AZ4 with steel tripod & scope together would be about 13kg. Using a Skytee would be about 17-18kg. My dob only weighs 25-26kg and the thought of having two heavyish set-ups didn’t really resonate with me. Also the cost of both those set ups would be between £700-£1000.
 

I ended up plumping for a full set-up for £550 that weighed just over 6kgs. I’m now a huge advocate of smaller aperture scopes and would make the same decision again. I’m using the scope every time conditions allow - the best scope etc.

As with John’s post, that’s my preference though. I’ve always been a lazy sod 😅 but I have no excuses with such a light set-up.

  • Like 1
Link to comment
Share on other sites

Among refractors, a 102mm, or 4", is the "sweet spot" among the varying apertures of the design; not too large, nor too small, just right rather.  I had to work up to one myself.  At the age the 8 or 9, I got my very first telescope, a Sears(Towa) 60mm/2.4" f/11 achromat...

kit5.jpg.0746d4ad06ff8a45c8d2df20f8fdc20e.jpg

It needs restoring, as it is almost fifty years old.  It had also gone through a conflagration, yet survived.  I intend to keep it as original as possible, tripod and all.  It was through that telescope that I observed my very first object ever: Saturn, and with my late father who had first found the planet, and then called me out from the house to look.  Saturn was sharp, small, yet sharp as a tack, with an eerie fluorescent-green colouration, and likely due to the planet's lower position, somewhat above the horizon.

That was my only telescope until I was 27.  I then got a Parks Optical(Towa) 80mm/3.1" f/11...

372868960_ParksPRT-813d.jpg.07d5ee111926279349b40c4024a52eef.jpg

That second was quite an upgrade from the first.

Eventually, I gave that one to a relation, and after its upgrade.  My first upgrade from that one was a Vixen 102mm/4" f/9.8 achromat...

1406289885_Vixen102mmf9_8d.jpg.123c9dc854cb6883d40e8eea088da4a9.jpg

But I returned that one after having it for only a few days.  I had simply and quickly decided that for my definitive 4" refractor, I wanted something else, something special.  That was in 2003, and the same year I acquired a 102mm/4" f/8 fluorite-apochromat...

FS-102q.jpg.cb6a017ecc57fcf82755b91f8a6e5aa9.jpg

I knew, even back then, that it would be most unlikely that I would ever get one larger than that, and for the rest of my life.  To this day, that still holds true, more than ever. 

Then, we have this, the modern incarnation of that one...

https://www.firstlightoptics.com/takahashi-fc-100-series-refractor-telescopes/tak_tfk10310.html

Edited by Alan64
  • Like 3
Link to comment
Share on other sites

There is absolutely no rush whatsoever in picking out one's definitive refractor; the longer the wait, the better actually.  Play with the mirrors, first.

However, in the meantime, I feel that you, also, might work up to one?  A little taste of what might come...

https://www.firstlightoptics.com/evostar/sky-watcher-capricorn-70-eq1-refractor.html

...a 70mm f/12.9 achromat.

I have one of those myself.  I got it just this past summer...

SC2c.jpg.2313856897648294cc19e0b116a8b271.jpg

Although, that kit is a combination from three others, one from early 1980s, 39 years ago...

Before-After2.jpg.34219bd19d607307fb669dcd6ea0e286.jpg

We go about our daily lives seeing with our eyes, which employ lenses.  Then, there are lensing-galaxies in space, which act as refractors in revealing older objects behind them, and magnified...  

https://www.youtube.com/watch?v=51YYnaIWzsU

Are you not in the least bit curious as to what a refractor might offer?

  • Like 1
Link to comment
Share on other sites

I would recommend looking through a smaller refractor before purchasing anything. At first I was quite surprised how small the image was through an 80mm but I’ve now grown to love and see great detail in that image.

I think my intention is to get a 4” eventually, although I can feel the Tak 76dcu’s gravitas pulling me towards it first. Maybe one day on a lovely Berlebach tripod and suitable mount… 💸💸💸

  • Like 1
Link to comment
Share on other sites

I initially started with a Russian-made 10X30 monocle, given to me at the age of 14 by my uncles at Christmas 1981, then at 16 in 1983 I bought a 60/700 achromatic refractor from my savings, the Konus Hydra with which I made of the beautiful observations of the Sun, of which I still keep most of the drawings, of the Moon and of some deep-sky objects when in summer we went to my father's town, Orotelli, in central Sardinia, in Cagliari where I lived (almost in the extreme south of Sardinia) between light pollution and having to be content with looking out of the windows there was not much to see. The 60/700 I made the mistake of giving it away because in 2010 I got the CPC 8 for 1750 euros in promotion (which I no longer have as it was stolen from me by thieves in the summer of 2012). I also bought some other achromatic refractors such as the Konusuper 120 (which, due to a chip in the edge of the doublet, recently used a 90 mm diaphragm, becoming a 90/1000 refractor with which I made some beautiful observations of Mars and also on the Moon do not mind at 250X and 333X) or the Konus Vista - 80, bought used a year and a half ago that I use to see the Sun with a full aperture glass filter that I already had and also the panoramas. This refractor surprised me by the fact that it defends itself well even on the Moon and planets surprising me a lot, in an Italian forum I read the reason: it was still produced by the Japanese in the orange version, the blue one was all made in China and on a review in Italian it is spoken very badly. In 2011 I bought for when I go down to Cagliari and not do astronomical fasting an achromaticone of the Ziel 120/600 (the Gem 60) which, despite its chromatism, very evident on the Moon and Venus, at 150X on our satellite is beautiful and also on Mars at 200X I did not mind last autumn, on the deep - sky I used it very little. I got used this summer the Vixen 102/1000 vintage achromatic refractor, the 102 - M which I don't mind on Jupiter, but I used it little. contemplative observations; we see. The fact that this summer here in Sardinia the night sky was painful because of the Sahara sand carried by the sirocco; I was hoping for a slightly dry autumn but the rainy season is starting or, if it doesn't rain, the sky is always a bit cloudy, there is too much wind and the temperature has dropped (today I also put my sweater on inside the house here in Orotelli: it's a pity, I was hoping for a de facto extension of the Mediterranean summer! The still high price of apochromatics doesn't make me want to buy one: for the same price you can buy a nice computerized reflector and see more , then I do not want to say "I do not drink this water" ... .... It is very true that my achromatics / achromats in front of a beautiful Takahashi apochromat disappear but of course they bleed the wallet! Of course, pure apochromats or ED 80 mm and 500 mm focal lengths make beautiful photographs of deep sky objects and are light, so they don't need a sturdy mount, but I don't feel the need to photograph DSOs, I continue to remain an (almost) pure visualist .
@mikeDnight: I really liked your drawings, some of them look like black and white photographs from how well they are done: really congratulations !!!

  • Like 1
Link to comment
Share on other sites

6 hours ago, IB20 said:

I would recommend looking through a smaller refractor before purchasing anything. At first I was quite surprised how small the image was through an 80mm but I’ve now grown to love and see great detail in that image.

I'd definitely want to do this before splashing out. Sadly the current situation make it unlikely for a little while yet I think.

Link to comment
Share on other sites

I had put my drawings on Mars in an astronomy forum in Italian to which I am posting the links:

Drawings of Mars with achromatic 80/400 and 120/1000 diaphragm at 90 mm:
https://astro.forumfree.it/?t=78477104#

Drawings of Mars with achromatic 120/600:
https://astro.forumfree.it/?t=78404004

If you want and time to see them, give me an opinion, consider that drawing I have never been much.

Link to comment
Share on other sites

I'm still reading through everyone's suggestions and recommendations, thanks.👍  This does raise another question though...🙄  The late Sir Patrick Moore, used to recommend a refractor of no less than 3" (76.2mm) in diameter.  How does that advice hold up in the 21st Century, with modern optics and advances in technology?🤔

Link to comment
Share on other sites

He was talking about old school achromatic refractors. There are plenty of smaller ED scopes around today that are great, especially for low power, wide field viewing and imaging of course.

Personally though, for visual stargazing, you can't beat a good 4" refractor. A very good all-round performer. Big enough to show you the sights but small enough to still be portable.

  • Like 1
Link to comment
Share on other sites

6 minutes ago, Ian McCallum said:

I'm still reading through everyone's suggestions and recommendations, thanks.👍  This does raise another question though...🙄  The late Sir Patrick Moore, used to recommend a refractor of no less than 3" (76.2mm) in diameter.  How does that advice hold up in the 21st Century, with modern optics and advances in technology?🤔

Technology has certainly come along a lot, and with modern production methods and coatings I’m sure the best 3” scopes are likely to be better than most of the older kit. There are plenty on here who have little Taks (60mm) and love them. The older scopes tended to be long focal lengths (f15 ish) and so were great for lunar and planetary targets as well as doubles, but not for widefield viewing, unlike the modern ones which are more likely to be f6 or 7.

That said, a 3” scope is still a 3” scope. Much depends on the targets you are interested in and what your eyes are like. I’ve owned and used many 2.5” and 3” apo scopes (including Tak and Televue) over the years and have enjoyed their benefits of ‘go anywhere’, quick setup, widefield views and beautiful star rendition. I now find that my eyes are struggling more with the smaller exit pupils you get at high magnifications and so prefer 4” or larger scopes. You do get that extra resolution too which helps for lunar, planetary and doubles.

So, what is your situation, what are your eyes like and what do you want the scope to achieve?

  • Like 1
Link to comment
Share on other sites

5 minutes ago, Stu said:

So, what is your situation, what are your eyes like and what do you want the scope to achieve?

My situation is a Bortle 6 sky, in my early 50's and need glasses to read, but not for observing or distance work. My eyesight prescription hasn't really changed that much, as I do get them tested every 2 years.  The scope would be for some lunar work, planetary, etc.  For DSO's and wide field, I can use my 200P with a 2" 28mm LET eyepiece which does give some lovely views.👍

Link to comment
Share on other sites

4 minutes ago, HiveIndustries said:

So jealous of Bortle 6...

Even though our streetlights are predominantly LED's, there is a sodium streetlight that does cause some problems for me whilst I'm in the back garden.  Also, many neighbours have bright flood lights that cause light pollution too!🤬

Link to comment
Share on other sites

2 minutes ago, Ian McCallum said:

Even though our streetlights are predominantly LED's, there is a sodium streetlight that does cause some problems for me whilst I'm in the back garden.  Also, many neighbours have bright flood lights that cause light pollution too!🤬

 

So, grass is always greener my friend. I'm in the shadow of the lights of NYC at a solid Bortle 9. I'm lucky enough to have a double lot but pollution from neighbors is that 10x literally. I gotta battle my own families bathroom light and kitchen lights even!

All that means is I've been limited to planets and lunar for the time being and traveling to dark sites is going to be my future.

There's nothing wrong with dwelling on these things as a newb though, they're kind of absolutely mind blowing and one could spend a lot of time just looking at them for years.

Link to comment
Share on other sites

3 hours ago, Ian McCallum said:

I'm still reading through everyone's suggestions and recommendations, thanks.👍  This does raise another question though...🙄  The late Sir Patrick Moore, used to recommend a refractor of no less than 3" (76.2mm) in diameter.  How does that advice hold up in the 21st Century, with modern optics and advances in technology?🤔

I've got a 3" refractor and it gives beautiful views (I haven't had a chance to take it out under properly dark skies yet though) and will take 50x per inch magnification very easily and go a fair bit higher in decent seeing on brighter objects and double stars. I've also got a little 60mm scope that's perfect for grab-and-go and doubles as a spotting scope - its views of the night sky are surprisingly good and last night I used it to see Rigel's companion for the first time, despite Orion being pretty low in the sky. For a long time 60mm was pretty much the standard size for a decent entry level refractor and many astronomers will have learned their craft using just such a scope from brands like Carton and Unitron (before my time though).

Optics are better but eyes are the same so the light gathering of a small scope will be a limiting factor (imaging is a different matter where small refractors come into their own), so if you can stretch to a 4" scope then it'll be worth getting. What you have to remember is that when Sir Patrick was giving that advice, modern apo refractors didn't exist (or were new on the market in the 80s and came with an eye-watering price tag), a 3" achromat was surprisingly expensive by today's standards and a 4" model was a rare thing that cost a fortune. Achromats also needed much longer focal ratios to maintain acceptable levels of colour correction so if your 4" scope had to be f/15 then you're dealing with a very long and heavy scope with quite serious mounting requirements.

I'm itching to get a 4" refractor and the nice thing with today's offerings is that I can get one that is barely any heavier than some of the 70-80mm scopes out there and much shorter than the old achromats so it would be very portable and work with the same mount I use for my smaller scopes.

  • Like 1
Link to comment
Share on other sites

Quote

As I wrote before, I too started with a 60/700 refractor that didn't mind the Sun and the Moon and allowed you to browse the most notable DSOs. Living 11 months in Cagliari and only the month of August in Orotelli when my father took vacation, I was fine. He was also a small instrument that easily found its place in the trunk of my father's car along with all the family's luggage when we went to Orotelli. These days I will definitely buy a vintage 60/800 that I found at an affordable price. Surely the small achromatic refractors should be re-evaluated because:
1) they are not very expensive;
2) they are easily transportable on vacation.
What about the apochromats, apart from their still expensive price even after the "Chinese revolution" of the 90s which lowered the price of telescopes? For me they are excellent photographic tools for DSOs that do not weigh much, such as 80/400 pure apochromats or ED, which therefore do not require too expensive mounts; or they are beautiful travel telescopes if one cannot bear the short achromatic defects (chromatism, too much spherical aberration, unglued optics, etc.)

 

Link to comment
Share on other sites

On 10/10/2021 at 06:03, HiveIndustries said:

 

So, grass is always greener my friend. I'm in the shadow of the lights of NYC at a solid Bortle 9. I'm lucky enough to have a double lot but pollution from neighbors is that 10x literally. I gotta battle my own families bathroom light and kitchen lights even!

All that means is I've been limited to planets and lunar for the time being and traveling to dark sites is going to be my future.

There's nothing wrong with dwelling on these things as a newb though, they're kind of absolutely mind blowing and one could spend a lot of time just looking at them for years.

Have you looked into getting an observing hood to block local stray light?  Even a black towel covering your head would help.

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
 Share

  • 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.