TAKAHASHI FSQ-80FC ASTROGRAPH
The Takahashi FSQ-80FC is a newly-designed apochromatic Petzval quintuplet astrograph with uncompromising performance for wide-field deep sky imaging with modern CMOS sensors.
With two fluorite elements in the front triplet and rear doublet flattening optics, the FSQ-80FC combines the superior on-axis correction of the TOA series with the flat field characteristics of the FSQ series.
The objective cell has been newly-designed to support the 5-element lens assembly, ensuring both optical precision and long-term mechanical stability.
The FSQ-80FC has a focal length of 450mm covering 5.6 degrees of sky and a focal ratio of f/5.6, making it the ideal instrument for capturing large nebulae. At prime focus, the telescope provides a 50mm image circle, comfortably covering full-frame sensors.
The RMS spot diameter (averaged across eleven wavelengths from 436 to 656nm) is 0.8μm at the centre, 2.2μm at the edge of a full-frame sensor, and 3.0μm at the edge of the 50mm image circle. Additionally, illumination across the field is exceptional at 97% at the edge of a full-frame sensor.
Not only is the FSQ-80FC a high-end astrograph, but its chromatic correction and extremely sharp on-axis performance makes it a formidable visual telescope. Despite its relatively fast f/5.6 focal ratio, the telescope achieves an on-axis Strehl ratio of 99.7%, exceeding even the TOA series. Even at high magnifications, there is no detectable colour fringing caused by the telescope optics.
The focuser includes Takahashi's MEF micro-focus unit with 1:8 reduction ratio, resulting in smooth and precise focusing for both visual observation and astrophotography. A new adapter ring system with male M48 x 0.75 and M54 x 0.75 thread adapters and 55mm backfocus allow easy connection to common modern imaging systems.
Matching 95mm tube rings from Prima Luce Lab are also available, allowing you to take full advantage of their PLUS universal system for connecting a multitude of accessories.
Note: does not include tube rings or a dovetail bar. For the FSQ-80FC, you can use the PrimaLuceLab 95mm PLUS tube rings in combination with the PrimaLuceLab 240mm Losmandy bar.
Specifications
| Optical design | Double Fluorite Apochromat |
|---|---|
| Lens cell |
Quintuplet with 5 lenses in 5 groups, 2 x Fluorite lenses |
| Coatings |
Hard multicoatings |
| Objective diameter |
80 mm |
| Focal length at prime focus |
450 mm |
| Focal ratio at prime focus |
F/5.6 |
| Backfocus distance at prime focus |
159 mm |
| Tube diameter | 95 mm |
| Dew shield diameter | 114 mm |
| Tube length | 559 mm with dew shield extended, 486 mm with dew shield retracted |
| Tube weight | 4.1 kg |
| SKU | TQE08041 |
Items included
- FSQ-80FC OTA
- TKP37001 - Coupling DT (FSQ-85ED)
- TKA23200N - CAA-M
- TKA23250 - Aux Ring FB 52mm
- TKP00005 - M48 Visual Adapter
- TKP00200 - M72-M48 CMOS Adapter
- TKP00101 - Ocular Adapter (31.7)
Downloads
 FSQ-80FC instruction manual
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