Small aperture, long focal length refractors

Discuss your refractor type scopes here.
Post Reply
User avatar
Lady Fraktor Slovakia
Co-Administrator
Co-Administrator
Articles: 0
Offline
Posts: 9860
Joined: Mon Apr 29, 2019 9:14 pm
4
Location: Slovakia
Status:
Offline

Small aperture, long focal length refractors

#1

Post by Lady Fraktor »


I posted this at AF.net a couple of years ago and thought it would be good to bring over here.

There are many people buying these scopes lately and when asking questions about them, somewhere along the line the comment of the quality comes up.

These 60, 70 and 80mm long focus refractors are actually quite reasonable for the money but where they fall down is the included accessories and the supplied mounts.

Recommended upgrades:

The mount! At a minimum, look for a used EQ-2 or EQ-3 (preferable) in the usual places.
(kijiji, Goodwill, Buy & Sell, Cloudy Nights, AF classifieds)

Replace the 20 or 25mm eyepiece the scope came with for a better quality one.
The Plossl design works very well with these longer focal length scopes and will not cost much per eyepiece.

The 4mm or 6mm eyepiece that normally comes with these can be kept in a drawer for use in sacrifices to the vengeful/ spiteful cloud deities.

The supplied barlow… if it is the all plastic “shorty” version do your eyes a favour and place it in the drawer with the 4mm eyepiece.
If it is one of the longer versions (6” long) and you are handy with woodworking tools, make a bud vase for your significant other. It will at least have a meaningful purpose.

The diagonal.
Replace with any of the name brand 1.25” available on the market today.
You will see a difference in the view!

The following list is what you can see with a 50mm and 80mm refractor on a good night.
If you have a 60mm or 70mm your results of course will be somewhere in the middle.

The first column is the object viewed, second is “seen in 50mm” and the third is “seen in 80mm”

Have fun hunting :D


Object: 50mm refractor : 80mm Refractor
Lunar Craters: 1500+ : 5000+
Phases of Mercury: Y : Y
Phases of Venus: Y : Y
Mars Polar Caps: N : Y
Mars Surface Markings: N : Y
Jupiter Belts/ Zones/ GRS: N : Y
Galilean Moons: Y : Y
Saturn Rings: Y : Y
Cassini Division: N : Y
Saturn Moons: 3 : 6
Uranus/ Neptune Visible: Y : Y
Uranus/ Neptune as a Disk: N : Y
Asteroids (10 Brightest): 3 : 10
Messier Objects: 77 : 110
Split Sirius A/B: N : Y
Split Epsilon Lyrae: N : Y
Split Trapezium in M42: N : Y
Horsehead Nebula visible: N : Y
See Form Of M27 (Dumbbell Nebula): N : Y
See Form Of M97 (Owl Nebula): N : Y
See Far Sticks: Antares Elita 103/1575, AOM FLT 105/1000, Bresser BV 127/1200, Nočný stopár 152/1200, Vyrobené doma 70/700, Stellarvue NHNG DX 80/552, TAL RS100/1000, Vixen SD115s/885
EQ: TAL MT-1, Vixen SXP, AXJ, AXD
Az/Alt: AYO Digi II/ Argo Navis, Stellarvue M2C/ Argo Navis
Tripods: Berlebach Planet (2), Uni 28 Astro, Report 372, TAL factory maple, Vixen ASG-CB90, Vixen AXD-TR102
Diagonals: Astro-Physics, Baader Amici, Baader Herschel, iStar Blue, Stellarvue DX, Takahashi prism, TAL, Vixen flip mirror
Eyepieces: Antares to Zeiss
The only culture I have is from yogurt
My day was going well until... people
Image
User avatar
StarBru United States of America
Orion Spur Ambassador
Articles: 0
Offline
Posts: 662
Joined: Mon May 13, 2019 1:53 am
4
Location: Arizona, USA
Status:
Offline

TSS Awards Badges

Re: Small aperture, long focal length refractors

#2

Post by StarBru »


Great advice for beginners! I started out with a Japanese 60mm refractor way back when, and of course they had the 0.965 eyepieces with impossibly small lenses. Very frustrating at times, but that still didn't stop me from squeezing out all I could see with that scope! Imagine my surprise when I received an Astroscan and was able to see so much more with a larger primary and of course, 1.25" eyepieces!

I have two 60mm refractors now, the Jason with a 1.25" adapter and the Meade NG model that already has the 1.25" focuser. It is so nice to use better eyepieces and accessories on these scopes!
Bruce

Refractors: Meade AR-5 127mm f/9.3, Meade ST-80 f/5 and Meade 60mm f/12, Jason 60mm f/15 #313, Jason 60mm f/12 #306 S7, Bushnell Sky Chief III 60mm f/15.
Reflectors/Catadioptrics: Meade 10" F/4 Schmidt-Newtonian, Galileo 120mm f/8.3 Newtonian, Meade 2045D 4" f/10 SCT, Meade ETX-90EC f/13.8 & Sarblue 60mm f/12.5 Maksutov-Cassegrains.
Mounts: Skywatcher EQ6-R Pro & Meade LXD55 Equatorial mounts, ES Twilight II and Meade 2102 ALT/AZ mounts, a modified 10" SkyQuest Dobsonian mount, various 60mm EQ mounts.
Misc: Celestron 20x80mm binoculars, Revolution II Imager/accessories, & lots of optical accessories/eyepieces.
Projects: 8" f/2.9 and 65mm f/10 reflectors, Dobson-style binocular mirror mount.
User avatar
Thefatkitty Canada
Co-Administrator
Co-Administrator
Articles: 0
Offline
Posts: 4133
Joined: Sat May 11, 2019 4:20 pm
4
Location: Ontario, Canada
Status:
Offline

TSS Awards Badges

TSS Photo of the Day

Re: Small aperture, long focal length refractors

#3

Post by Thefatkitty »


Couldn't agree more Gabby; a lot of my scopes fall into the "old and modified" category.

Being aware I will probably be heckled for this...:

One thing is the 60mm's usually have a focuser where the outside diameter is the same as a 1.25" eyepiece/accessory. Remove the drawtube, replace it with and old barlow with the lens cut out, and some plastic, duct tape and hose clamps, you have a much more useful scope.
01.JPG
04.JPG
05.JPG
06.JPG

As for the 80mm's, the drawtube has the same OD as a 1.25" part. That's easier:
002.JPG
Image002.jpg
Image003.jpg

Also helps to put some jar caps over the stock focuser wheels; makes for easier fine adjustments...
Image004.jpg
If you're wondering, all the parts have machined ends, so you just butt them up, tighten the clamps, and it's going to be perfectly straight :D

Let the criticism begin... :lol:
Mark

"The Hankmeister" Celestron 8SE, orange tube Vixen made C80, CG4 & AZ-EQ5 mounts.
Too much Towa glass/mirrors.

H/A - PST stage 2 mod with a Baader 90mm ERF on a Celestron XLT 102 (thanks Mike!)
Ca-K - W/O 61mm, Antares 1.6 barlow, Baader 3.8 OD and Ca-K filters with a ZWO ASI174mm.
W/L - C80-HD with Baader 5.0 & 3.8 Solar film, Solar Continuum 7.5nm and UV/IR filters with a Canon EOS 550D.

Oh yeah, and Solar Cycle 25 :D
User avatar
Ylem United States of America
Universal Ambassador
Articles: 0
Offline
Posts: 7477
Joined: Sun May 12, 2019 2:54 am
4
Location: Ocean County, New Jersey
Status:
Offline

TSS Photo of the Day

Re: Small aperture, long focal length refractors

#4

Post by Ylem »


I had a nice Sears 70 as a kid.
Miss that scope.
Clear Skies,
-Jeff :telescopewink:


Member; ASTRA-NJ



Orion 80ED
Celestron C5, 6SE, Celestar 8
Vixen Porta Mount ll
Coronado PST
A big box of Plossls
Little box of filters
:D



User avatar
astrowolf67
Earth Ambassador
Articles: 0
Offline
Posts: 35
Joined: Sun Dec 01, 2019 5:10 pm
4
Location: Western Kentucky
Status:
Offline

Re: Small aperture, long focal length refractors

#5

Post by astrowolf67 »


These scopes are not bad at all, with some inexpensive upgrades. Definitely try to obtain one with at least an EQ2 mount. Here is an old Sears 60mm I picked up a few years ago, shown beside a 102mm Mak. I added a hybrid diagonal, and use mid grade plossls with it, and, it provides some very pleasing images. Plus, they are great for solar projection also. I even called it to duty during the eclipse of 2017. The moon pic was taken afocal, just by holding my phone over the eyepiece.
Attachments
Sears Scope 2.jpg
Sears Eclipse 3.jpg
Sears Eclipse.jpg
Sears Moon 2.jpg
David
Celestron 8" Starhopper Dob, Meade Starfinder EQ 8", Apertura 6" F/5, Meade 114NT, Edmund Astroscan, ES AR102, Sky Watcher 102mm Mak, ETX 80, ETX 60, Orion ST80, Sears Discoverer 4 6333a, Meade LXD75, ES Twilight 1, Star Adventurer 2i
User avatar
Lady Fraktor Slovakia
Co-Administrator
Co-Administrator
Articles: 0
Offline
Posts: 9860
Joined: Mon Apr 29, 2019 9:14 pm
4
Location: Slovakia
Status:
Offline

Re: Small aperture, long focal length refractors

#6

Post by Lady Fraktor »


There were some very good 24.5mm (0.965") eyepieces made in the past and a few of the older manufacturers are producing them again.
Siebert Optics in USA and ATC in Czech Republic can custom make focal lengths as well.
I have a 11mm Siebert Optics that competes well with my TeleVue 11mm Plossl.
See Far Sticks: Antares Elita 103/1575, AOM FLT 105/1000, Bresser BV 127/1200, Nočný stopár 152/1200, Vyrobené doma 70/700, Stellarvue NHNG DX 80/552, TAL RS100/1000, Vixen SD115s/885
EQ: TAL MT-1, Vixen SXP, AXJ, AXD
Az/Alt: AYO Digi II/ Argo Navis, Stellarvue M2C/ Argo Navis
Tripods: Berlebach Planet (2), Uni 28 Astro, Report 372, TAL factory maple, Vixen ASG-CB90, Vixen AXD-TR102
Diagonals: Astro-Physics, Baader Amici, Baader Herschel, iStar Blue, Stellarvue DX, Takahashi prism, TAL, Vixen flip mirror
Eyepieces: Antares to Zeiss
The only culture I have is from yogurt
My day was going well until... people
Image
User avatar
Buckethead 2.0
Milky Way Ambassador
Articles: 0
Offline
Posts: 1417
Joined: Sun May 19, 2019 5:25 pm
4
Location: Maine, USA
Status:
Offline

Re: Small aperture, long focal length refractors

#7

Post by Buckethead 2.0 »


Thanks, Gabrielle. Very useful info.
~Eric
Binos: Bushnell Falcon 10x50
User avatar
Bigzmey United States of America
Moderator
Moderator
Articles: 8
Offline
Posts: 7548
Joined: Sat May 11, 2019 7:55 pm
4
Location: San Diego, CA USA
Status:
Offline

TSS Awards Badges

Re: Small aperture, long focal length refractors

#8

Post by Bigzmey »


Nice write up Gabby! I would add if you upgrading diagonal, get a prism :)
Scopes: Stellarvue: SV102ED; Celestron: 9.25" EdgeHD, 8" SCT, 150ST, Onyx 80ED; iOptron: Hankmeister 6" Mak; SW: 7" Mak; Meade: 80ST.
Mounts: SW: SkyTee2, AzGTi; iOptron: AZMP; ES: Twilight I; Bresser: EXOS2; UA: MicroStar.
Binos: APM: 100-90 APO; Canon: IS 15x50; Orion: Binoviewer, LG II 15x70, WV 10x50, Nikon: AE 16x50, 10x50, 8x40.
EPs: Pentax: XWs & XFs; TeleVue: Delites, Panoptic & Plossls; ES: 68, 62; Vixen: SLVs; Baader: BCOs, Aspherics, Mark IV.
Diagonals: Baader: BBHS mirror, Zeiss Spec T2 prism, Clicklock dielectric; TeleVue: Evebrite dielectric; AltairAstro: 2" prism.
Filters: Lumicon: DeepSky, UHC, OIII, H-beta; Baader: Moon & SkyGlow, Contrast Booster, UHC-S, 6-color set; Astronomik: UHC.

Observing: DSOs: 3106 (Completed: Messier, Herschel 1, 2, 3. In progress: H2,500: 2180, S110: 77). Doubles: 2382, Comets: 34, Asteroids: 255
User avatar
terrynak
Orion Spur Ambassador
Articles: 0
Offline
Posts: 808
Joined: Sat Jun 08, 2019 3:58 am
4
Location: Los Angeles
Status:
Offline

TSS Awards Badges

Re: Small aperture, long focal length refractors

#9

Post by terrynak »


Hi Gabrielle,

I'm currently enjoying my collection of 50mm-60mm long focal length refractors, as you've probably noticed on the Reports Sub-Forum. Especially for lunar and double star observing from my heavily LP skies. Again, very nice list that you provided earlier (Double Star Marathon Observing List).
Scopes: Reflectors, refractors, and 1 catadioptric. Ranging in aperture from 50mm to 150mm.
Post Reply

Create an account or sign in to join the discussion

You need to be a member in order to post a reply

Create an account

Not a member? register to join our community
Members can start their own topics & subscribe to topics
It’s free and only takes a minute

Register

Sign in

Return to “Refractor type Telescopes”