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telescopecomparison · 2-way

William Optics Ultra-Cat 108 vs SharpStar 94EDPH

William Optics Ultra-Cat 108
William Optics

Ultra-Cat 108

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

SharpStar 94EDPH
SharpStar

94EDPH

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

Key differences

+15% aperture
Faster by 0.7 f-stops

Specifications

SpecificationWilliam Optics Ultra-Cat 108SharpStar 94EDPH
Optics
Typerefractorrefractor
Optical designPetzval (5-element advanced)Apo triplet FPL-53
Aperture108mm94mm
Focal length518mm518mm
Native f/ratiof/4.8f/5.5
Image circle60mm44mm
Full-frame supportYesYes
Physical
Weight8.0kg4.5kg
Advantages of William Optics Ultra-Cat 108
  • 15% more light-gathering aperture
  • Faster optics at f/4.8 vs f/5.5
  • Larger image circle (60mm) — supports bigger sensors
Advantages of SharpStar 94EDPH
  • Lighter (4.5kg vs 7.96kg) — easier to travel with
Best for — William Optics Ultra-Cat 108
  • Large emission nebulae and star clusters
  • Fast imaging — short exposures per sub
  • Full-frame astro cameras and DSLRs
Best for — SharpStar 94EDPH
  • Large emission nebulae and star clusters
  • Full-frame astro cameras and DSLRs
William Optics Ultra-Cat 108 — typical FOV & scale
  • With Full-frame (36×24mm, 3.76µm)
    FOV: 3.98° × 2.65°Scale: 1.50"/px
  • With APS-C (23.5×15.7mm, 3.76µm)
    FOV: 2.60° × 1.74°Scale: 1.50"/px
  • With IMX533 square (11.3×11.3mm, 3.76µm)
    FOV: 1.25° × 1.25°Scale: 1.50"/px
SharpStar 94EDPH — typical FOV & scale
  • With Full-frame (36×24mm, 3.76µm)
    FOV: 3.98° × 2.65°Scale: 1.50"/px
  • With APS-C (23.5×15.7mm, 3.76µm)
    FOV: 2.60° × 1.74°Scale: 1.50"/px
  • With IMX533 square (11.3×11.3mm, 3.76µm)
    FOV: 1.25° × 1.25°Scale: 1.50"/px
William Optics Ultra-Cat 108 — recommended user

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

SharpStar 94EDPH — recommended user

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

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