The Takahashi FSQ-85EDX comes with a Flattener. Optional optical accessories are the Extender ED 1.5x and the Reducer QE 0.73x. The Extender is great to take pictures of Galaxies and Star clusters while the Reducer is ideal for large nebulae such as the Heart Nebula or the North America Nebula etc.

I recently used the Extender for the first time and realized that, in order to reach critical focus, the standard Auxiliary Ring has to be removed. Although Takahashi has convenient system charts (see also at the end of this page) for each setup, I thought it might be useful to publish a few pictures of the different setups. The system charts also include the adapters needed for CCD cameras (I will soon write more on how to attach a CCD camera as well).

Below is a picture of the standard setup with Flattener (& optional T-Mount DX-WR ring for my Nikon – Takahashi is also producing the same ring for the EOS):

Takahashi FSQ-85EDX Standard setup with Flattener & optional T-Mount DX-WR (here for Nikon)

Setup with Flattener

Here a close-up picture of the standard setup with Flattener:

Standard setup with Aux.Ring TSA-102 and Flattener 1.01X. Optional accessories: T-Mount DX-WR (Nikon)
From left to right: Auxiliary Ring, Flattener and T-Mount DX-WR (with LPS Filter)

Setup from left to right:
– Coupling (FSQ-85ED)
– CAA(TSA-102)
– Aux.Ring (FB) (TSA-102)
– Flattener 1.01X
– T-Mount DX-WR (Nikon) (also available for Canon EOS)

Setup with Extender ED 1.5x

In order to reach critical focus with the Extender ED 1.5x you have to remove the Aux.Ring (FB) and attach the 50.8(2”) Eyepiece Adapter S to the CAA, followed by the Extender and the CA-35 (50.8/2″). The T-Mount adapter is the same as for the Flattener. For accurate balancing you’ll probably also have to attach the pipe clamps higher up on the dovetail bar:

Optional setup with Extender-ED 1,5x

Setup from left to right:
– Coupling (FSQ-85ED)
– CAA(TSA-102)
– 50.8(2”) Eyepiece Adapter S
– Extender ED 1.5X
– CA-35 (50.8/2″)
– T-Mount DX-WR (Nikon) (also available for Canon EOS)

For comparison, below you’ll also find two subs taken of Andromeda Galaxy. The picture on the left was taken with the Flattener (180s at ISO 1600), the picture on the right was taken with the Extender ED 1.5x (300s at ISO 1600):

Setup with Reducer QE 0.73x

While I haven’t yet used the Reducer, I’ll post a picture of the setup below – the pipe clamps have to be at the same position as for the Flattener (this is not the case on this picture which is only meant for illustration of the setup):

Setup from top to bottom:
– Coupling (FSQ-85ED)
– CAA(TSA-102)
– Reducer QE 0.73x
– CA-35 (SKY 90) adapter
– T-Mount DX-WR (Nikon) (also available for Canon EOS) – not shown on this picture

Technical Data Takahashi FSQ-85EDX refractor

CHARACTERISTICTAKAHASHI FSQ-85EDX REFRACTOR
Length of the optical tube623 mm (535 mm with retracted dew shield)
Diameter of the optical tube95 mm
Diameter of the dew shield114 mm
Weight3.6 kg
FocuserRack-and-pinion with 1/7 microfocuser
Source: Takahashi Europe
CHARACTERISTICTAKAHASHI FSQ-85EDX REFRACTOR
ObjectivePetzval Quadruplet with ED glass
Lens cellHighly air-spaced quadruplet. 4 lenses/4 groups. 2 x S-FPL53 ED lenses
CoatingsHard multicoatings
Diameter85 mm
AT PRIME FOCUS
Focal length450 mm
Focal ratioF/5.3
Metal Back Distance197.5 mm
WITH 1.01X FIELD CORRECTOR
Focal length455 mm
Focal ratioF/5.4
Image circle diameter44 mm
Metal Back Distance56.2 mm
WITH RD QE0.73X FOCAL REDUCER
Focal length327 mm
Focal ratioF/3.8
Image circle diameter44 mm
Metal Back Distance72.2 mm
WITH EX ED1.5X FOCAL EXTENDER
Focal length680 mm
Focal ratioF/8
Image circle diameter44 mm
Metal Back Distance117.5 mm
Source: Takahashi Europe

Links to System Charts Refractor, Reducer & Extender

System-chart of Takahashi FSQ-85EDX refractor
System-chart of Takahashi FSQ-85EDX refractor with RD QE0.73X
System-chart of Takahashi FSQ-85EDX refractor with EX ED1.5

Disclaimer: I’m not affiliated to Takahashi or any other company mentioned on my website.

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