Getting Started

LensHH-LT runs on Windows, Linux, and macOS:

• Windows: download the Inno Setup installer and run it.
• Linux: download the AppImage, mark it executable, and run it.
• macOS: build from source — see the README for instructions.

See the Download page for full details.

System Requirements

• Windows 10/11, Linux, or macOS (64-bit)
• .NET 8 Runtime (bundled with the Windows installer and Linux AppImage)
• 4 GB RAM minimum, 8 GB recommended
• Internet connection for activation (one-time). Offline activation available for air-gapped machines.

User Guide (PDF)

The user guide ships with the installer as a searchable HTML help bundle and a PDF. Open it from Help → User Guide in the application, or view the latest version directly on GitHub:

Download User Guide PDF →

Activation

Free Trial

To start a 45-day free trial:

1. Open LensHH-LT
2. Go to Help → Start Free Trial
3. Enter your email address
4. Check your email for a 6-digit activation code
5. Enter the code in the application

The trial is full-featured with no limitations. One trial per email address, valid on one machine.

License Activation

After purchasing a license:

1. Go to Help → Activate License
2. Enter your license key (format: LHLT-XXXX-XXXX-XXXX-XXXX)
3. Click Activate

Each license can be activated on up to 2 machines. To move a license, use Help → Deactivate This Machine on the old machine first.

Offline Activation

For air-gapped machines without internet access, use the CLI on any connected machine:

license fetch-token LHLT-XXXX-XXXX-XXXX-XXXX <machineId> token.json

Transfer token.json to the target machine, then:

license offline token.json

Lens Editor

The lens editor displays the optical system as a spreadsheet-style surface table. Each row represents one surface.

Surface Properties

• Radius — radius of curvature (mm). Use Infinity for flat surfaces.
• Thickness — distance to the next surface (mm).
• Material — glass name (e.g., N-BK7) or MIRROR for reflective surfaces.
• Semi-Diameter — clear aperture half-diameter (mm).
• Conic — conic constant (0 = sphere, -1 = paraboloid).

Analysis

Available under the Analysis menu:

• Paraxial data (EFL, BFL, F/#, magnification, pupils)
• FFT MTF (vs. frequency, vs. field, vs. focus)
• Geometric MTF
• Spot diagrams
• Ray fans and OPD fans
• Distortion and field curvature
• Seidel aberration coefficients
• Relative illumination
• Lateral color and chromatic focal shift
• Wavefront maps
• FFT PSF
• System data

Optimization

Local Optimization

Damped least-squares (Levenberg-Marquardt) optimizer. Set variables on surfaces, define a merit function, and run Optimization → Local Optimization.

Multistart Global Search

Randomizes variables around the current solution and runs many short local optimizations in parallel. Finds the best result across all trials.

Basin Hopping

Hooke-Jeeves direct search combined with LM polishing — good when the topology is fixed but the local minimum needs to be escaped.

Synthesis by Saddle-Point Construction

Grows the design one element at a time by finding saddle points in merit-vs-curvature space. Can insert single elements or cemented doublets, restricted to either side of the stop. Turns a single lens into a multi-element system in one run.

Split Element & Search Best Asphere Surface

Targeted topology growth: split the highest-aberration element into two glasses, or aspherize the surface that gives the most merit improvement.

File Formats

Native Format (.lhlt)

JSON-based format that preserves all data including merit function, variables, and constraints.

Import

• Zemax (.zmx) — surfaces, aspherics, conics, fields, wavelengths
• Code V (.seq) — surfaces, aspherics, conics, fields, wavelengths
• OSLO (.len) — surfaces, aspherics, conics, wavelengths
• Optalix (.otx) — surfaces, aspherics, conics, fields, wavelengths
• Optiland (.json) — surfaces, aspherics, conics, fields, wavelengths

Export

Export to all supported formats via File → Export As.

Command Line Interface

LensHH-LT includes a CLI for scripting and batch operations:

lenshh open mylens.lhlt
paraxial
fft-mtf
spot
optimize 500
save result.lhlt

Support

Email: support@synapseoptics.com