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telescopecomparison · 2-way

Takahashi FC-100DL vs William Optics GT 102

Takahashi FC-100DL
Takahashi

FC-100DL

Best suited for intermediate imagers building a versatile kit running a portable travel rig.

William Optics GT 102
William Optics

GT 102

Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.

Key differences

+28% focal length
Slower by 2.1 f-stops

Specifications

SpecificationTakahashi FC-100DLWilliam Optics GT 102
Optics
Typerefractorrefractor
Optical designApo doublet fluoriteApo triplet FPL-53
Aperture100mm102mm
Focal length900mm703mm
Native f/ratiof/9.0f/6.9
Image circle44mm44mm
Full-frame supportNoYes
Physical
Weight3.3kg5.6kg
Advantages of Takahashi FC-100DL
  • Tighter framing — 900mm vs 703mm focal length
  • Lighter (3.3kg vs 5.6kg) — easier to travel with
Advantages of William Optics GT 102
  • Wider field — 703mm vs 900mm focal length
  • Faster optics at f/6.9 vs f/9
Best for — Takahashi FC-100DL
  • Medium-sized galaxies and planetary nebulae
  • High-resolution long-exposure work
Best for — William Optics GT 102
  • Medium-sized galaxies and planetary nebulae
  • Full-frame astro cameras and DSLRs
Takahashi FC-100DL — typical FOV & scale
  • With Full-frame (36×24mm, 3.76µm)
    FOV: 2.29° × 1.53°Scale: 0.86"/px
  • With APS-C (23.5×15.7mm, 3.76µm)
    FOV: 1.50° × 1.00°Scale: 0.86"/px
  • With IMX533 square (11.3×11.3mm, 3.76µm)
    FOV: 0.72° × 0.72°Scale: 0.86"/px
William Optics GT 102 — typical FOV & scale
  • With Full-frame (36×24mm, 3.76µm)
    FOV: 2.93° × 1.96°Scale: 1.10"/px
  • With APS-C (23.5×15.7mm, 3.76µm)
    FOV: 1.92° × 1.28°Scale: 1.10"/px
  • With IMX533 square (11.3×11.3mm, 3.76µm)
    FOV: 0.92° × 0.92°Scale: 1.10"/px
Takahashi FC-100DL — recommended user

Best suited for intermediate imagers building a versatile kit running a portable travel rig.

William Optics GT 102 — recommended user

Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.

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