# Lenses — Knowledge Base

> Cinema primes, photo primes, anamorphic, and specialty lenses. Use when generating image/video prompts to specify focal length, aperture, and character.

## Focal length quick reference

| Focal length | Type | Use case |
|--------------|------|----------|
| 8-16mm | Ultra-wide / Fisheye | POV, action, distortion |
| 18-24mm | Wide | Establishing, vlog, landscape |
| 28-35mm | Slightly wide | Documentary, two-shot |
| 40-50mm | Standard | Natural perspective, medium shot |
| 70-85mm | Short telephoto | Portrait, close-up |
| 100-135mm | Telephoto | Reaction shot, isolation |
| 200mm+ | Long telephoto | Sports, wildlife, extreme compression |

## Aperture guide

| Aperture | Effect | When to use |
|----------|--------|-------------|
| f/1.2 - f/1.4 | Maximum bokeh, very shallow DOF | Portrait, isolation |
| f/2.0 - f/2.8 | Shallow DOF, versatile | Cinematic standard |
| f/4 - f/5.6 | Medium DOF | Wide shots with environment |
| f/8 - f/11 | Deep DOF | Landscape, group shots |
| f/16+ | Maximum sharpness, hyperfocal | Architecture, infinite focus |

## Lens character vocabulary

When writing prompts, use these descriptors:

### Cooke (warm, organic)
- "Cooke S4" → warm bokeh, vintage glow, slight softness
- "Cooke Anamorphic" → horizontal lens flares, oval bokeh, 2x squeeze

### Zeiss (clinical, sharp)
- "Zeiss Master Prime" → ultra-sharp, neutral color, modern
- "Zeiss Otus" → photo equivalent of Master Prime

### ARRI Signature
- "ARRI Signature Prime" → modern cinema, gentle falloff, premium

### Leica
- "Leica Summilux" → vintage character, signature rendering

### Sony G Master
- "Sony G Master" → modern, sharp, neutral

### Canon RF
- "Canon RF" → warm color science, autofocus-optimized

### Vintage Soviet
- "Helios 44-2" → swirly bokeh, dreamy, signature look

## Composition rules — focal length impact

- **Wide (24mm)** — exaggerates space, characters look smaller, environment dominates
- **35mm** — natural human eye, documentary feel
- **50mm** — neutral, no distortion
- **85mm** — compression, beautiful subject isolation, portrait standard
- **135mm** — heavy compression, intimate, voyeur feel

## Anamorphic explanation

Anamorphic lenses optically squeeze a wider image onto the sensor:
- 2x squeeze means 2.39:1 final aspect ratio
- Signatures: horizontal lens flares (blue/orange), oval (not round) bokeh
- Use for: epic cinematic feel, sci-fi, music videos

## Lens + camera mount compatibility

| Camera | Compatible mounts |
|--------|-------------------|
| ARRI Alexa | LPL, PL (with adapter) |
| RED | RF, EF, PL (with adapter) |
| Sony Venice | E-mount, PL |
| Sony A-series | E-mount |
| Canon R | RF, EF (with adapter) |
| Nikon Z | Z-mount, F (with adapter) |

When recommending, ensure mount compatibility.

## Prompt examples

- "Shot on Sony A7 IV with Sony G Master 85mm at f/1.4, shallow depth of field"
- "Anamorphic horizontal flares from Cooke 32mm Anamorphic at T2.3, 2.39:1 cinemascope"
- "Vintage swirly bokeh from Helios 44-2 at f/2.0"
- "Macro detail captured at 1:1 magnification with 100mm macro at f/2.8"
