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telescopecomparison · 2-way

William Optics RedCat 61 vs SharpStar 61EDPH III

William Optics RedCat 61
William Optics

RedCat 61

Best suited for beginners and wide-field enthusiasts running a portable travel rig.

SharpStar 61EDPH III
SharpStar

61EDPH III

Best suited for beginners and wide-field enthusiasts running a portable travel rig.

Key differences

-10% focal length
Faster by 0.6 f-stops

Specifications

SpecificationWilliam Optics RedCat 61SharpStar 61EDPH III
Optics
TypeRefractorRefractor
Optical designPetzval APODoublet APO
Aperture61mm61mm
Focal length300mm335mm
Native f/ratiof/4.9f/5.5
Image circle45mm32mm
Full-frame supportYesNo
Physical
Weight2.0kg2.4kg
Advantages of William Optics RedCat 61
  • Wider field — 300mm vs 335mm focal length
  • Faster optics at f/4.9 vs f/5.5
  • Larger image circle (45mm) — supports bigger sensors
  • Lighter (2kg vs 2.4kg) — easier to travel with
Advantages of SharpStar 61EDPH III
  • Tighter framing — 335mm vs 300mm focal length
Best for — William Optics RedCat 61
  • Wide-field nebulae and Milky Way regions
  • Fast imaging — short exposures per sub
  • Full-frame astro cameras and DSLRs
Best for — SharpStar 61EDPH III
  • Wide-field nebulae and Milky Way regions
William Optics RedCat 61 — typical FOV & scale
  • With Full-frame (36×24mm, 3.76µm)
    FOV: 6.88° × 4.58°Scale: 2.59"/px
  • With APS-C (23.5×15.7mm, 3.76µm)
    FOV: 4.49° × 3.00°Scale: 2.59"/px
  • With IMX533 square (11.3×11.3mm, 3.76µm)
    FOV: 2.16° × 2.16°Scale: 2.59"/px
SharpStar 61EDPH III — typical FOV & scale
  • With Full-frame (36×24mm, 3.76µm)
    FOV: 6.16° × 4.11°Scale: 2.32"/px
  • With APS-C (23.5×15.7mm, 3.76µm)
    FOV: 4.02° × 2.69°Scale: 2.32"/px
  • With IMX533 square (11.3×11.3mm, 3.76µm)
    FOV: 1.93° × 1.93°Scale: 2.32"/px
William Optics RedCat 61 — recommended user

Best suited for beginners and wide-field enthusiasts running a portable travel rig.

SharpStar 61EDPH III — recommended user

Best suited for beginners and wide-field enthusiasts running a portable travel rig.

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