Leviathan 2" m48x0.75 - Spectral Pro Shorty Filter Cell

When “Standard” Isn’t Standard

Not all 2″ (M48×0.75) mounted filters are mechanically identical.

Many modern filter wheels and drawers have strict internal clearance limits. While most 2″ filters share the same thread specification, cell height above the mounting shoulder often varies by manufacturer and even between samples in a specific product line, and even small differences can prevent a filter from seating correctly or rotating freely.

Users frequently discover this only after installation.

The Leviathan Shorty Filter Cell is engineered specifically to eliminate those issues.

Designed for Real-World Compatibility

The Shorty Cell is a precision-machined, ultra-low-profile M48×0.75 filter mount designed to minimise axial height while maintaining structural rigidity and optical security.

Key Features:

• Ultra-low axial height above the mounting shoulder

• Fully compliant M48×0.75 thread geometry

• Precision-controlled tolerances

• Black-anodised, low-reflectance interior

• Secure retaining ring for 2 mm or 3 mm optical substrates

By reducing unnecessary flange thickness and excess thread depth, the Shorty Cell ensures compatibility with:

• Low-clearance electronic filter wheels

• Tight carousel systems

• Slim filter drawers and sliders

• Compact backfocus-critical imaging trains

Why Cell Height Matters

Most filter wheels specify a maximum allowable mounted filter height (often ~7 mm or less). However:

• Some mounted 2″ filters exceed this limit by fractions of a millimetre

• Tolerance stack-ups between wheel pocket depth and filter cell height can prevent rotation

• Adjacent filters in a carousel may interfere with one another

Even a 0.2–0.3 mm difference can be enough to cause mechanical binding.

The Shorty Cell is dimensioned specifically to sit comfortably within these clearance envelopes.

Engineering Approach

At Leviathan Optical Engineering, we treat mechanical interfaces with the same discipline as optical design.

The Shorty Cell is:

• CNC-machined for dimensional consistency

• Designed to maintain concentricity and squareness

• Engineered to avoid unnecessary material where it adds no mechanical value

The result is a compact, mechanically honest filter mount that prioritises compatibility without compromising structural integrity.

Intended Applications

• Astrophotography filter wheels with strict internal height limits

• Slim M48 filter drawers

• Imaging systems with tight backfocus budgets

• Retrofit of high-performance optical substrates into lower-profile mounts

Lead time - shipping 18/03/26