Results 1 to 8 of 8
Like Tree7Likes
  • 6 Post By Barnacle
  • 1 Post By Barnacle

Thread: Tasco 9F 60mm refractor telescope's true aperture

  1. #1
    Barnacle's Avatar
    Barnacle is offline White Dwarf
    Points: 3,235, Level: 37
    Level completed: 24%, Points required for next Level: 115
    Overall activity: 3.0%
    Achievements:
    First 1000 Experience Points365 Days+ Registered Achievement!750 Days+ Registered Achievement!1000 Days+ Registered Achievement!3 Years + Achievement
    Join Date
    May 2015
    Location
    Australia
    Posts
    5
    Points
    3,235
    Level
    37
    Thanks
    0
    Thanked 1 Time in 1 Post

    Default Tasco 9F 60mm refractor telescope's true aperture



    I recently acquired a used 1980s Tasco 9F red tube 60mm refractor telescope (focal length =800mm), which has the built in flip down finderscope using a prism. The objective lens was made by Tanzutsu in Japan.

    Images of what this telescope looks like:
    https://www.astromart.com/classified...fied_id=913487

    First light had me suspecting its 60mm objective lens was stopped down, as looking at Betelguese, its star light was rather dim for a 60mm…

    Upon examination with a flashlight test, I noticed that the baffle inside the telescope tube has stopped the aperture of the telescope from 60mm to 50mm, something which is not uncommon for refractors old and new.

    In order to open the aperture back to 60mm, one will need to push the baffle as far back as possible towards the eyepiece end until it hits the first set if screws of the built in finderscope housing. Only then, will you have a true 60mm refractor telescope.

    The other thing I noticed was the crown and flint elements of the achromatic objective lens required rotation to remove astigmatism as it was not aligned properly when assembled during manufacture.

  2. #2
    Peter802's Avatar
    Peter802 is offline HYPER GIANT
    Points: 17,115, Level: 90
    Level completed: 48%, Points required for next Level: 185
    Overall activity: 0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!50 Posts Achievement!5 Threads Achievement!365 Days+ Registered Achievement!
    Join Date
    Feb 2016
    Location
    United Kingdom. At present in Germany.
    Posts
    4,301
    Points
    17,115
    Level
    90
    Thanks
    704
    Thanked 1,427x 1,403 Posts
    Blog Entries
    1

    Default Re: Tasco 9F 60mm refractor telescope's true aperture

    Nice looking scope.
    Enjoy using it.
    Clear skies.
    Peter.


    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    : Bresser AR-127S 635mm. Celestron Travel
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    70. Mount: Bresser EXOS - 2 modified to belt drive and AstroEQ mount controller.
    Cameras: Un modded Canon 450D.
    Bino's: Nikon Aculon A211. 16x50 4.2 degs.

  3. #3
    Cyclops's Avatar
    Cyclops is offline Bright Giants
    Points: 7,165, Level: 59
    Level completed: 8%, Points required for next Level: 185
    Overall activity: 5.0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!5 Threads Achievement!50 Posts Achievement!Ghost Achievement! Averaging 5+ posts a day!
    Join Date
    Aug 2012
    Location
    Darlington, England
    Posts
    234
    Points
    7,165
    Level
    59
    Thanks
    15
    Thanked 34x 26 Posts

    Default Re: Tasco 9F 60mm refractor telescope's true aperture

    Similar to one I had years ago but yours looks better. Have fun with it.
    ​There's coffee in that nebula! Opticron 3" spotter,
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    GoScope III 70mm Travel
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    , Bresser 10x50s, Bresser Hunter 7x50s, Canon 30D and IXUS compact camera, one eye!

  4. #4
    Barnacle's Avatar
    Barnacle is offline White Dwarf
    Points: 3,235, Level: 37
    Level completed: 24%, Points required for next Level: 115
    Overall activity: 3.0%
    Achievements:
    First 1000 Experience Points365 Days+ Registered Achievement!750 Days+ Registered Achievement!1000 Days+ Registered Achievement!3 Years + Achievement
    Join Date
    May 2015
    Location
    Australia
    Posts
    5
    Points
    3,235
    Level
    37
    Thanks
    0
    Thanked 1 Time in 1 Post

    Default Re: Tasco 9F 60mm refractor telescope's true aperture

    Quote Originally Posted by Cyclops View Post
    Similar to one I had years ago but yours looks better. Have fun with it.
    Hi All,

    Thanks for the reply posts!

    Clarification:
    The photos of that particular scope in the link is not mine.

    I have the same Tasco 9F model, but mine is very old and worn & weathered, as the previous owner has left it outside to the elements.

    As an example, the bluish optical coating on the objective lens no longer exists on mine, rather the lens looks uncoated with tiny peeled-look residues of remnant clear coating after cleaning.

    However, once the crown and flint lens elements have been rotated, I was able to split Rigel's double star system with my Tasco 9F at 123x using a 6.5mm symmetrical/dialsight eyepiece (commonly mislabelled as a plossl when they are made in China).

    My post is to inform others that in order to make the max of this Tasco 9F scope, they need to push the telescope tube baffle towards the eyepiece end as much as possible, as it was set on manufacture to stop the scope down from 60mm to 50mm instead.

    To reach the baffle and hammer it back with a broom stick, one needs to unscrew the heavy alumina dew shield (the dew cap screws into the alumina telescope main tube), which includes the objective lens housing.

    This extra 10mm regained makes a big difference in a small long focal length frac.

  5. #5
    Cyclops's Avatar
    Cyclops is offline Bright Giants
    Points: 7,165, Level: 59
    Level completed: 8%, Points required for next Level: 185
    Overall activity: 5.0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!5 Threads Achievement!50 Posts Achievement!Ghost Achievement! Averaging 5+ posts a day!
    Join Date
    Aug 2012
    Location
    Darlington, England
    Posts
    234
    Points
    7,165
    Level
    59
    Thanks
    15
    Thanked 34x 26 Posts

    Default Re: Tasco 9F 60mm refractor telescope's true aperture

    The question is what are new Tascos like? The one I had in the 80s (600x60) was dreadful. Tho it lasted me into the 90s, by then it was just a plastic tube forced on to a camera tripod, barely useable. The eyepieces (12 and 6mm) were dreadful.
    ​There's coffee in that nebula! Opticron 3" spotter,
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    GoScope III 70mm Travel
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    , Bresser 10x50s, Bresser Hunter 7x50s, Canon 30D and IXUS compact camera, one eye!

  6. #6
    TOTSUWA's Avatar
    TOTSUWA is offline Main Sequence
    Points: 1,808, Level: 26
    Level completed: 8%, Points required for next Level: 92
    Overall activity: 0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!50 Posts Achievement!5 Threads Achievement!200+ Posts Achievement!
    Join Date
    Feb 2018
    Location
    Bel Air, MD
    Posts
    153
    Points
    1,808
    Level
    26
    Thanks
    11
    Thanked 17x 16 Posts

    Default Re: Tasco 9F 60mm refractor telescope's true aperture

    A Tasco 60MM was my first scope back in the 80's, which was when I was last active in amateur astronomy. They had a reputation as being a cheap junk telescope with Japanese accessories and eps. However, I enjoyed the daylights out of that old scope; I wish I still had it.
    Two tired old brown eyes; Meade
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    90EQ; Meade ETX60AT; Vixen 20x80 Binoculars
    Member - Harford County Astronomical Society
    Harford County, Maryland USA

  7. #7
    Barnacle's Avatar
    Barnacle is offline White Dwarf
    Points: 3,235, Level: 37
    Level completed: 24%, Points required for next Level: 115
    Overall activity: 3.0%
    Achievements:
    First 1000 Experience Points365 Days+ Registered Achievement!750 Days+ Registered Achievement!1000 Days+ Registered Achievement!3 Years + Achievement
    Join Date
    May 2015
    Location
    Australia
    Posts
    5
    Points
    3,235
    Level
    37
    Thanks
    0
    Thanked 1 Time in 1 Post

    Default Re: Tasco 9F 60mm refractor telescope's true aperture

    Hi All,

    I acquired another second hand Tasco 9F 60mm scope in better condition than the first.

    Again, the baffle acts as an "aperture stopper" from 60 mm to 50mm, so the Tasco 9Fs are all set at 50mm on manufacture.

    Attached are photos of the scope with light test showing it is operating at 50mm due to baffle being set too forward towards the objective lens.

    The third photo shows inside the tube, the ring is where the baffle used to be located, with no matt black paint after I pushed towards the eyepiece end, so metal shinning thru.

    The new location of the baffle can be seen in the crescent slit looking down the tube, now sitting right in front of the two screws that house the flip prism finders cope casing.

    Final photo shows the light test with the opening at 60mm.

    Hope everyone can make the most of their Tasco 9 F by unscrew at the objective end and push down the baffle, as the Tanzutsu objective lens is very good.

    Should not be set to perform at 50mm, and should be deployed at its full aperture at 60mm instead.

    PS: haven't check yet if the objective lens requires rotation to eliminate astigmatism, hope not as the aluminium retainer ring looks hard to remove without professional lens ring openers.

    Kind regards,

    Bill
    bladekeeper likes this.

  8. #8
    bladekeeper's Avatar
    bladekeeper is offline Super Moderator
    Points: 306,881, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 100.0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!5 Threads Achievement!50 Posts Achievement!200+ Posts Achievement!
    Awards:
    Activity Award
    Join Date
    Aug 2014
    Location
    Lowell, Arkansas, USA
    Posts
    39,015
    Points
    306,881
    Level
    100
    Thanks
    29,137
    Thanked 17,683x 12,109 Posts

    Default Re: Tasco 9F 60mm refractor telescope's true aperture

    Hi Bill!

    Unfortunately image uploading is broken and we have been unable to get the admin to fix the issue (among many). As a result, the bulk of the forum membership have moved on to greener pastures: https://www.theskysearchers.com/index.php

    Hope to see you there!
    Bryan

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    :
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    f/5; Celestron C6-R f/8; ES AR127 f/6.4; ES AR127 f/9.4; Stellarvue SV102T f/7; ES AR102 f/9.8;
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    MC90 f/13.3;
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    ST80A f/5; Celestron Premium 80 f/11.4; Celestron C80 f/11.4; Unitron Model 142 f/16; Meade NG60 f/10
    Mounts: Celestron AVX; Bresser EXOS-2; ES Twilight I; ES Twilight II; iOptron Cube-G; AZ3/wood tripod; Vixen
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

    Eyepieces: GSO Super Plössl 40mm, 32mm, 15mm, 9mm; ES 82° Series; GSO Superview 30mm; Celestron Plössl 26mm, 20mm; ES 70° 25mm; ES Plössl 25mm; Vite Aspheric 23mm, 10mm, 4mm; Orion Expanse 20mm, 9mm; KK Ortho 18mm, 12.5mm; Bresser 70° 15mm; Coulter Optical 12.5mm; BCO 10mm; ES 62° 9mm; Zhumell Z Series 5mm
    Binoculars: Pentax PCF WP II 10×50, Bresser Corvette 10×50, Bresser Hunter 16×50 and 8×40, Garrett
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    12×60 LW, Gordon 10×50, Apogee 20×100

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.


    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

    Galaxy Hunter's Creed - When you play whack-a-mole, sometimes you hit 'em on the head, sometimes you miss 'em. But its always fun to play, and if you don't play, you ain't gettin no moles! - KT4HX

 

 

Similar Threads

  1. For Sale: Vintage Tasco branded .965 accessory bundle for 60mm Telescope
    By Leveye in forum Astronomy Classifieds
    Replies: 0
    Last Post: 04-18-2017, 03:32 AM
  2. 1960 Tasco 60mm f/15 Telescope
    By njjmfm in forum Telescope Forums
    Replies: 3
    Last Post: 11-24-2014, 06:25 PM
  3. Tasco 19T 60mm aperture 800mm focal length: Pretty Good
    By andro-mike-eda in forum Astronomy Reports Forum
    Replies: 2
    Last Post: 01-12-2014, 03:56 AM
  4. Tasco Galaxsee 675X Refractor Telescope.. Help!?
    By Sandra D in forum Refractor Telescopes Forum
    Replies: 5
    Last Post: 03-10-2011, 03:12 PM
  5. Replies: 2
    Last Post: 06-20-2008, 10:03 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Powered by vBulletin® Version 4.2.0
Powered by vBulletin®
All times are GMT. The time now is 05:30 PM.