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Old 18-04-2019, 11:10 AM
Starbuck3108 (Dan)
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Some advice for observation work and short refractors

Currently my only scope is an 80 mm refractor (FL 555mm) which I know is definitely not ideal for observational work, but I was wondering if anyone here has managed to get OK results from short refractors for large/bright nebulae? If so what eye pieces? I am aware that I would need to be somewhere pretty dark for even the slightest chance.

Or is this just totally futile?
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Old 18-04-2019, 02:59 PM
casstony
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The sky looks interesting even with the naked eye from a very dark site Dan, so you should get decent low magnification views through the 80mm at a dark site. If you want to push up to say 100x where many DSO's look better you'd need a larger aperture.
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Old 18-04-2019, 03:11 PM
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mental4astro (Alexander)
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Not futile at all, Dan!

On the contrary, a scope like yours, by keeping the magnification down as low as practical, nebulae are excellent targets.

The trick is patience. Be patient with your scope and be patient with your eyes.

With the Milky Way high up over us for the next few months, there's plenty of nebulosity to discover. Sure it won't be a large mage, but it will be small and precious. Galaxies are feasible too, but only as smal, soft faint fuzzies. And don't forget open and globular clusters.

* As far as nebulae go, there is M42 in Orion.
* There is masses of dark nebulosity that riddles the Milky Way itself, which is purely the domain for a small scope like yours!
* There is the Eta Carina complex (big and rosette-like).
* There are MANY nebulous areas all around Eta Carina, and bucket loads of open Clusters, including the Gem, Pearl and Jewel Box clusters.
* The Coal Sack between the Southern Cross & Centaurus is a totally different proposition in your scope at low power!
* Further East as Scorpio rises, the giant open cluster M7 is criss crossed they fingers of dark nebulosity, all invisible to big scopes!
* With Sagittarius up, there is the gorgeous area around M8 and M20, and the open cluster M21 is right beside M20. This entire area is a super rich hunting ground as here lies the Cloud of Sagittarius, the densest star cloud in the sky.
* And lastly there is M16 and M17.

Globular clusters:
* Omega Centauri - your scope is very capable of resolving it. You'll need to up the magnification for this.
* 47 Tuc, a bit of a challenge at this time of year.
* M22 in Sagittarius and M4 in Scorpio.

Galaxies:
* The Small & Large Magellanic Clouds. The LMC is also riddled with nebulosity, and of course the Tarantula Nebula.
* Centaurus A (NGC 5128). You should be able to easily spot the dark lane that cuts it in half.
* Markarian's Chain! A ribblon of galaxies in Virgo.

Need more? Just ask!

Alex.
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Old 18-04-2019, 05:49 PM
Wavytone
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Not at all futile with small refractors. The issue however is the "short" bit.

A couple of weeks ago we had a nice night where - among other things - someone set up an antique Vixen 60mm f/15 achro refractor. It was quite blast to use this - and a very salient reminder of how perfect a long achro refractor (f/15) could be. FWIW despite my "big mak", I have a very nice 70mm refractor, both as a grab & go, and for my son.

IMHO the pressure from the imaging crowd for ever-shorter refractors has quite seriously damaged refractors - manufacturers could do better IMHO by splitting their ranges into two two distinct groups - fast APO's for imaging, vs much slower scopes optimised for visual.

Last edited by Wavytone; 18-04-2019 at 06:19 PM.
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Old 18-04-2019, 08:45 PM
Wilso
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I'm still a firm believer less glass is more in these small aperture scopes.
I have a couple of these and think the Tak Le's and pesudo masuyama's preform the best for these scopes, light weight (good for balancing) sharp and have excellent contrast. Still have eye relief compared to orthos.
The best low power view with a small scope I've had under a dark sky site was with a 40mm eyepiece with my Fsq
(Oversize exit pupil Iknow)
I haven't tried any visual nebula filters yet so hopefully someone might chime in on this one.

Cheers
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Old 18-04-2019, 10:08 PM
Ukastronomer (Jeremy)
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Quote:
Originally Posted by Starbuck3108 View Post
Currently my only scope is an 80 mm refractor (FL 555mm) which I know is definitely not ideal for observational work, but I was wondering if anyone here has managed to get OK results from short refractors for large/bright nebulae? If so what eye pieces? I am aware that I would need to be somewhere pretty dark for even the slightest chance.

Or is this just totally futile?


WHY? would an 80mm scope be no good for this use............ ???
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Old 19-04-2019, 07:44 AM
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mental4astro (Alexander)
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Hi Jeremy, it stems from just not being aware of the strengths and weaknesses of different apertures.

Take binos - the most underestimated astro tool there is! Small aperture, but tthey are low magnification, meaning the image is concentrated, hence they are rich field scopes, and as you use both eyes, our brain combines the image from both eyes into one richer image than we can get from using one eye. All this means thete are details that binos (and other rich field scopes) can reveal that are very difficult or even impossible for larger apertures and longer focal lengths to show.

I LOVE my 100mm f/5 refractor! I can see the wider context of a DSO with its immediate surrounds. I can see the lacework dark nebulosity that riddles M7 inside and out that is totally invisible to my 17.5" dob! My big dob is absolutely useless for this!

We can get caught up thinking our gear is inadequate because we think it is too small - we just need to know the strengths of our gear and then exploit that to get the best from it

That is why I have 12 scopes, from 2" through to 17.5", four refractors, 1 Mak, 1 SCT, mostly Newts and a pair of 11X70 binos Some I use exclusively from home, others at dark sites, some for rich field, others as light buckets, couple just for Moon and planets, and even a couple for outreach and sidewalk astronomy. Oh, two of the fracs, one is a PST and the other is just for the Quark filter.

Hmmm, I could have a problem...

Dan, you have a very capable scope. Don't think otherwise

Alex.
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Old 19-04-2019, 04:47 PM
Ukastronomer (Jeremy)
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A1
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Old 19-04-2019, 11:36 PM
Renato1 (Renato)
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I've been using my little 80mm diameter 500mm focal length short tube refractor for over 20 years, despite owning much bigger telescopes - for a variety of roles such as
a travel telescope, and
as something that gives nice widefield views, and
as a quick grab and go telescope that I can use as quickly as I take it out of the house.

All the 600 or so deep sky objects listed in Tirion's Bright Star Atlas can be seen with it, though you'd need dark skies for the galaxies.

I mainly use 1.25" eyepieces with it, and my favourite is an old 16mm Widescan with 82 degree field, though I also have used 20mm and 25mm wide angle eyepieces. The other day I was using my 2" wideangle eyepieces in it (20mm, 25mm, 26mm and 30mm) for amusement, though they make it heavier.

You might want to try using a narrow band filter on your eyepiece to bring out nebula better, or putting the filter between the eyepiece and your eye and either tilting it up and down, or moving it side to side to spot the small planetary nebulas.

If your telescope is an achromat, you should be able to easily take it to between 100X to 125X when looking at the moon and planets, though you may need a yellow/green filter or fringe-killer filter to sharpen things up a bit.

My refractor has ED glass and I was looking at Jupiter at 200X with it the other night - which was a bit of over magnification, with not much contrast between the bands - but doing a lot of staring eventually showed quite a bit of detail. About 160X is really all mine is good for (it's not an expensive ED telescope).

I recollect many years ago at a club viewing night where I just took my 80mm for quick looks at the sky, as I was mainly there for chatting. Other members had their big telescopes out, and a husband and wife new members were wandering among the telescopes looking at objects being shown to them. Eventually, toward the end of the night, they made their way to my little telescope, where I showed them the M6 and M7 open clusters in Scorpius and a few other bright objects. The husband looked around to make sure no one was within hearing range and said to me,
"You know what?"
"What?"
"We've been here looking through all these telescopes, and the best views we've had all night have been through your telescope."

So, keep in mind, you don't have a limited or inferior telescope. I bought mine after getting an 8" one, and have used it nearly as often as my 8" and 14.5" telescopes.
Regards,
Renato
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Old 20-04-2019, 12:41 AM
Ukastronomer (Jeremy)
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Well I am happy with my 72mm for casual viewing
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Old 17-06-2019, 03:48 PM
whotfami (Garrett)
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Quote:
Originally Posted by Starbuck3108 View Post
Currently my only scope is an 80 mm refractor (FL 555mm) which I know is definitely not ideal for observational work, but I was wondering if anyone here has managed to get OK results from short refractors for large/bright nebulae? If so what eye pieces? I am aware that I would need to be somewhere pretty dark for even the slightest chance.

Or is this just totally futile?
I can see a lot with my 80 mm refractor. I have two eyepieces (25 mm and 10 mm) and they pretty much suffice. If you have a PC, I recommend download Stellarium and punch in your location and time, and it will show you what you want to see. If you have an android phone, I recommend Skyeye which will also point you in the right direction.
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Old 18-06-2019, 07:24 AM
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xelasnave
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I prefer my cheap 80mm binos for visual in most situations.
Alex
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Old 18-06-2019, 01:20 PM
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Outcast (Carlton)
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I agree with all that's already been stated in answer to your question...

My first serious scope was an 80mm refractor; admittedly a Meade Triplet but, still only an 80mm refractor.

The views were stunning.. I sold it when I bought my 8" SCT... I just bought another Meade 80mm APO Refractor... because I missed it so much.. regretted selling the old one about a week after it was gone...

I'm sending my sister a little Orion 80mm Short Tube refractor; I've used it myself, it's great, it's light & it's simple... If I thought it was rubbish & of no use, I wouldn't send it to my worst enemy...

From a dark site, every Messier object (with the exception of those visible in the Northern Hemisphere) are accessible; lots & lots of things are accessible. From your backyard (depending where you live), the moon, many planets, bright nebula & globular clusters should all be visible...

My love affair with Saturn began because of a stunning view through my little 80mm f6 (FL480mm) refractor..... so, faster than yours; with a 6mm EP I could clearly see the Cassini division... small image.. sure but, clear & sharp as...

Don't diss your scope bud... you'll be utterly amazed at the views you'll get.. bigger is not always better & the best scope there is, is the one you will use...

Enjoy this fantastic hobby... & checkout Alex's (mental4astro) observing guides in the beginner section.. they are invaluable...

Cheers
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