When the camera sensor reaches 1.1″ and above (including 4/3″), standard 2/3″ lenses vignette because their image circle is too small. This article compares Computar FA, motorized, motorized telecentric and visible/SWIR series for large-format use, with selection tips.
1. Why large-format sensors need dedicated lenses
The image circle must cover the sensor diagonal: a 1.1″ sensor is about 17.6mm diagonal, 4/3″ about 21.6mm, while a 2/3″ lens (~11mm) cannot cover it, causing corner vignetting and a sharp resolution drop.
2. The four Computar series compared
| Series | Positioning | Application |
|---|---|---|
| FA series | High-resolution fixed-focal | General machine vision, measurement |
| Motorized | Motorized zoom/focus | Remote focus, spec switching |
| Motorized telecentric | Low distortion, constant magnification | Precision & 3D inspection |
| Visible/SWIR | Wide-band transmission | SWIR inspection, penetration imaging |
3. Three selection steps
- Confirm the image circle by sensor format: 1.1″ and 4/3″ need dedicated large-format models;
- Choose resolution by pixel size and accuracy: high-megapixel cameras need matching MTF;
- Fix focal length/magnification by working distance and FOV, then verify the mount (mostly C-Mount).
4. FAQ
Can a large-format lens be used on a 2/3″ camera?
Yes. A larger image circle is backward-compatible with smaller sensors; only the field of view changes.
Can SWIR and large format be combined?
Yes. Some visible/SWIR models support both large format and the SWIR band — confirm by model specs.
See the full Computar lens lineup, or use the selector to filter by sensor format.