TAKAHASHI   TSA-120

 

* Another Beautiful  refractor from Takahashi *

 

 

The Starlight Instruments Feathertouch focuser is so awesome that we recommend it for all purchases of TSA120/TSA102.  Details of the standard Takahashi focuser on TSA-120 are shown further down this page.  For other details on the TSA-102 click here

 

 

Above shows the feathertouch focus assembly.  Points to note:

1. The black knobs on the focus shaft are for coarse focus adjustment. The brass knob at the top end is for fine adjustment (10:1 reduction in gear, and 10:1 reduction in torque)

2. There are three brass thumbscrews (one hidden in pic) on the front of  the focuser body, spaced at 120 around the periphery. These are for locking the whole focuser at any desired angle, so there is no need for a separate camera angle adjuster

3. There is a stainless stell thumbscrew for locking the main focus shaft.  This is very when imaging, where very accurate focus requires to be maintained.

4. The 2" back with the two stainless steel thumbscrews is the standard Takahashi back, compatible with all refractors of  4" or  more aperture.  The front of  this adapter is M72 male thread. Note that  further adapters for 1.25" eyepieces are optional extras and are not included as standard.

5.  The M72 female thread at the back of  the Starlight focus assembly is the same as on the standard TSA-120 (or TSA-102), so the standard photo-visual components are the same, with the exception that no camera angle adjuster (or M72 spacer) is required infront of  the focal reducer.

 

 

 Close-up of the top of  the focus assembly.  The brass thumbscrew at centre is for locking the main focus tube, useful for both visual and photographic applications.  The 'warning' label marks the location for a finder bracket on the left-hand side, and the two threaded holes to the right mark the location for a finder bracket on the right-hand side.

 

 

View showing the excellent quick-release finder bracket, which can accommodate finders from 50mm to 60mm diameter.  The finder retaining/adjusting screws are all nylon tipped, so no scratching of  the finder's paint or enamel can occur!

 

View showing a Takahashi 7x50 finder installed, plus a 2" diagonal mirror, step-down adapter and 1.25" eyepiece. Note that the finder is offset enough for there to be no head contact when viewing through a diagonal, and also that the finder can be slid back or forth in the bracket for most comfortable viewing position as required

 

 

The objective is a beautiful triplet!

 

 

                     TSA-120  with standard Takahashi focus assembly

 

Note that the TSA-120 is much much lighter than the TOA-130, and even lighter than the legendary FS-128.  The  new EM-11 mount can easily take this instrument, including any camera, filter wheel and auto-guider.

 

The TSA-120 does not come with a microfocuser as standard, so if  you want that option, you will require the MEF3 microfocuser option.

 

Specification

 

Objective  aperture 120mm 

Focal length  900mm

Focal ratio   f/7.5

Triplet super apochromat

Coating: broadband multi-layer, anti-reflective

2"/1.25" ocular adapters as standard

Retractable dewshield

Integral zero backlash microfocuser

Overall length - 990mm

Weight - 6.7Kg 

 

Optional items (see end of  main price list for full list)

 

Field Flattener

Focal length  882mm

Focal ratio f/7.3

Image resolution 7microns rms spot radius from on-axis to 20mm radius off-axis

Image circle 40mm (60% illumination)

Field 2.6 degrees

 

Focal Reducer

Focal length 672mm

Focal ratio f/5.6

Image resolution: 4 microns rms  spot radius on-axis

                             6 microns rms 10mm spot radius off-axis

                              13 microns rms spot radius 20mm off-axis  

Image circle 40mm diameter (60% illumination)

Field 3.4 degrees

                

SYSTEM CHARTS - Click to enlarge

           

 

 

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