Astrophotoguru · Compare

telescopecomparison · 2-way

William Optics Zenithstar 61 II vs William Optics RedCat 61

William Optics Zenithstar 61 II
William Optics

Zenithstar 61 II

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

William Optics RedCat 61
William Optics

RedCat 61

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

Key differences

+20% focal length
Slower by 1.0 f-stops

Specifications

SpecificationWilliam Optics Zenithstar 61 IIWilliam Optics RedCat 61
Optics
TyperefractorRefractor
Optical designApo doublet FPL-53Petzval APO
Aperture61mm61mm
Focal length360mm300mm
Native f/ratiof/5.9f/4.9
Image circle44mm45mm
Full-frame supportNoYes
Physical
Weight1.9kg2.0kg
Advantages of William Optics Zenithstar 61 II
  • Tighter framing — 360mm vs 300mm focal length
Advantages of William Optics RedCat 61
  • Wider field — 300mm vs 360mm focal length
  • Faster optics at f/4.9 vs f/5.9
Best for — William Optics Zenithstar 61 II
  • Large emission nebulae and star clusters
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
William Optics Zenithstar 61 II — typical FOV & scale
  • With Full-frame (36×24mm, 3.76µm)
    FOV: 5.73° × 3.82°Scale: 2.15"/px
  • With APS-C (23.5×15.7mm, 3.76µm)
    FOV: 3.74° × 2.50°Scale: 2.15"/px
  • With IMX533 square (11.3×11.3mm, 3.76µm)
    FOV: 1.80° × 1.80°Scale: 2.15"/px
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
William Optics Zenithstar 61 II — recommended user

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

William Optics RedCat 61 — recommended user

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

Recommended alternatives