AF and FF refer to different focusing mechanisms in cameras: Auto-Focus (AF) and Fixed-Focus (FF). The primary distinction lies in how the camera achieves focus.
Auto-Focus (AF)
Auto-Focus cameras use electronic systems to automatically adjust the lens to achieve sharp focus on a subject. This system typically involves a motor and sensors to detect and correct focus.
- Functionality: Automatically adjusts the lens for sharp focus.
- Mechanism: Employs Voice Coil Motor (VCM) to move the lens.
- Use Cases: General photography, where subjects are at varying distances.
- Limitations: Performance can degrade in high-vibration environments.
Fixed-Focus (FF)
Fixed-Focus cameras have a lens with a pre-set focus distance. Everything within a specific range from the camera will appear in focus, without any moving parts to adjust.
- Functionality: Focus is pre-set to a specific distance.
- Mechanism: No moving parts for focus adjustment.
- Use Cases: Situations needing robustness or simplicity. Good for high-vibration environments where autofocus systems can fail.
- Advantages: More reliable in high-vibration environments. According to the reference, Auto-Focus uses Voice Coil Motor (VCM) to move the magnet that is mounted to a free-moving lens. In high vibrations, this electromagnetic force is overpowered and the lens vibrates all over the place, causing blurry/weird/"jello" frames.
AF vs FF: Key Differences in a Table
| Feature | Auto-Focus (AF) | Fixed-Focus (FF) |
|---|---|---|
| Focus Method | Automatic adjustment via electronic systems. | Pre-set fixed distance; no adjustment. |
| Moving Parts | Yes, uses a motor (VCM) to move the lens. | No moving parts for focus. |
| Vibration Impact | Can be negatively affected in high-vibration environments, causing blurry images due to lens vibration. | More robust in high-vibration environments. |
| Applications | General photography, versatile for varying distances. | Environments with high vibration, or where simplicity and reliability are paramount. |
