📦 Overview

The MiniCat 51 WIFD is a fast, wide-field astrograph refractor designed primarily for astrophotography — especially for capturing star fields, nebulae, and other deep-sky targets. It combines a compact optical design with high image quality and portability, making it ideal for amateur astrophotographers and astronomy enthusiasts who want a lightweight system with serious performance.

🔭 Optical Design & Performance

• Focal Length: 178 mm — gives a wide field of view suitable for large deep-sky objects.

• Aperture: 51 mm with f/3.5 focal ratio — very fast optics that allow shorter exposure times and brighter images compared to slower refractors (f/5 and above).

• Lens Type: UltraFast 6-element Petzval optical design. This helps deliver sharp stars across the field.

• Glass Elements: Includes 2 Super ED elements and lanthanum glass, reducing chromatic aberration and improving contrast and color fidelity.

• Image Circle: 43.2 mm — supports large camera sensors (APS-C and compatible with full frame with proper correction).

Field Flattening

The Petzval design inherently produces a flat imaging field, meaning no additional field flattener is required for most cameras — simplifying setup and reducing extra accessories.

Note about edge stars:
Because of the very fast optical speed (f/3.5), edge stars may not be perfectly round without software correction — APS-C sensors correct well with tools like BXT, while full-frame may take a bit more adjustment.

🛠️ Focusing System – WIFD (William Internal Focus Drive)

One of the standout features of this model is the WIFD focusing mechanism:

• The focuser is relocated to the center of the optical path, eliminating a traditional rear drawtube.

• This helps minimize tube tilt when cameras or heavy accessories are attached — a common issue in astrophotography setups.

• Compatible with electronic focusers (EAF) for automated focusing in imaging workflows.

📸 Practical Features

Build and Usability

• Integrated Bahtinov Mask: Laser-engraved on stable PMMA plastic — makes focusing easier and more accurate during imaging sessions.

• Mounting Ring & Dovetail: Includes a dual-side plate that supports both Vixen-style and Arca-Swiss dovetail mounts for flexible mounting options.

• CAT Handle Bar: Helps with carrying and maneuvering the scope safely.

• Precision Adjustment: Tilt adjuster and camera angle rotator included — allows careful alignment and framing for astrophotography.

Portability

• Extremely lightweight for an astrograph:

  • Optical Tube Assembly (OTA): ~1.67 kg (3.68 lbs)

  • Total Weight (with accessories included): ~2.29 kg (5.05 lbs)

• Comes with a soft carry case and tools for setup.

📦 What’s in the Box

• MiniCat 51 WIFD optical tube

• Bahtinov focusing mask

• M48 camera adapter

• Dual-side mounting plate

• Mounting ring with handle

• Soft carry case

• Allen key set (for accessories and adjustments)

🌌 Imaging & Use Cases

This telescope is especially well-suited for:

• Wide-field deep sky astrophotography (nebulae, star clusters).

• Fast imaging sessions where short exposures are beneficial.

• Use with both dedicated astronomy cameras and DSLR/mirrorless cameras (with appropriate T-rings and adapters).

• Travel and portable setups due to its lightweight design.

🎯 Summary

The MiniCat 51 WIFD is a professional-grade fast wide-field astrograph refractor that brings together:

• Extremely bright optics (f/3.5) for efficient astrophotography

• Advanced Petzval design for a corrected flat imaging field

• Internal focus design (WIFD) for stable, precise operation

• Lightweight and portable construction for travel or field use

It’s an excellent choice for astrophotographers looking for a compact but powerful imaging setup that excels at wide-field targets without the bulk of larger telescopes.