C-Mount Lens for Dream Chip: 5mm, 8mm, 12mm or 16mm?
By TRM | Published: 2026-11-03
Category: Buying Guides
Pick a C-mount lens for your Dream Chip camera by sensor size, resolution, and field of view. Compare Kowa and Computar 5mm, 8mm, 12mm, and 16mm options.
Quick answer
Match the lens image circle to your Dream Chip sensor first, then pick focal length for field of view. For 2/3-inch sensors, the Kowa 5mm f/1.8 gives the widest view; for 1-inch sensors, the Kowa 8mm f/1.4 balances width and light; for 1.1-inch sensors up to 24MP, the Computar 12mm and 16mm preserve resolution.
Why sensor format decides before focal length
A C-mount lens only works cleanly if its image circle covers your sensor. The Kowa 5mm is specified for 2/3-inch sensors, the Kowa 8mm for up to 1-inch, and the Computar 12mm and 16mm for 1.1-inch with a 17.6mm image circle. Putting a smaller-format lens on a larger sensor usually causes heavy vignetting or dark corners. Check your Dream Chip model's sensor format in its datasheet before comparing angles of view.
Resolution and pixel size: the spec that limits sharpness
The Kowa 5mm is rated for 10MP and is intended for sensors with 2.5µm pixels or larger. The Kowa 8mm is rated for 5MP. The Computar 12mm and 16mm are rated for up to 24MP on 1.1-inch sensors. If your camera has smaller pixels or higher resolution than the lens is rated for, you may not get the full detail the sensor can capture. Use the lower-rated lens only when your output resolution or inspection tolerance allows it.
Aperture and light: when f/1.4 or f/1.8 matters
The Kowa 5mm f/1.8 and 8mm f/1.4 let in more light than the f/2.8 Computar lenses. That can shorten exposure in fast-moving machine vision lines or dim inspection setups. The trade-off is usually shallower depth of field at maximum aperture, so you may need to stop down for 3D parts or stacked scenes. The Computar f/2.8 lenses favor consistent sharpness across the frame when light is adequate.
Decision rules for your Dream Chip lens
- Start with sensor format: If your Dream Chip sensor is 2/3-inch, choose the Kowa 5mm. If it is 1-inch, choose the Kowa 8mm. If it is 1.1-inch, choose a Computar 12mm or 16mm. A lens with a smaller image circle than your sensor will vignette; do not rely on cropping.
- Then set field of view: For the widest coverage, pick the shortest focal length your sensor supports. For a tighter, more detailed view, move up: 5mm to 8mm to 12mm to 16mm. Estimate your working distance and target size before choosing; a longer focal length needs more distance for the same scene.
- Check resolution headroom: Match the lens MP rating to your camera: 5MP for the Kowa 8mm, 10MP for the Kowa 5mm, and 24MP for the Computar 12mm and 16mm. If your camera exceeds the lens rating, expect softer detail. Pixel size below 2.5µm on the Kowa 5mm falls outside its intended sensor range.
- Decide how much light you need: Choose f/1.4 or f/1.8 when motion blur or low light is a problem. Choose f/2.8 when you have enough light and want simpler focus across depth. Faster lenses can require stopping down for deep scenes, which reduces their light advantage.
Lens facts at a glance
- Dream Chip 5mm f/1.8 (LM5JC10M) (C-Mount) – Objectif Kowa: 5mm focal length, f/1.8, C-mount, 10MP rating for 2/3-inch sensors with 2.5µm pixels or larger. Widest view in this group, but only if your Dream Chip sensor is 2/3-inch and your pixel size is at least 2.5µm.
Dream Chip 5mm f/1.8 (LM5JC10M) (C-Mount) – Objectif Kowa - Dream Chip 16mm f/2.8 (V1628-MPY2) (C-Mount) – Objectif Computar: 16mm focal length, f/2.8, C-mount, covers 1.1-inch format with a 17.6mm image circle for cameras up to 24MP. Best for high-resolution 1.1-inch Dream Chip sensors when you need a tighter field of view and can accept f/2.8.
Dream Chip 16mm f/2.8 (V1628-MPY2) (C-Mount) – Objectif Computar - Dream Chip 8mm f/1.4 (LM8HC) (C-Mount) – Objectif Kowa: 8mm focal length, f/1.4, C-mount, covers sensors up to 1-inch and is rated for 5MP. A middle ground for 1-inch sensors that need more light than f/2.8 provides, with a wider view than 12mm or 16mm.
- Dream Chip 12mm f/2.8 (V1228-MPY2) (C-Mount) – Objectif Computar: 12mm focal length, f/2.8, C-mount, covers 1.1-inch format with a 17.6mm image circle and 24MP rating. Useful when a 1.1-inch sensor needs a moderately wide view without dropping to the 8mm's 1-inch coverage limit.
Who should choose which
Best for
- 2/3-inch Dream Chip cameras needing a wide view and 10MP detail (Kowa 5mm)
- 1-inch Dream Chip cameras that need a fast f/1.4 lens for low light (Kowa 8mm)
- 1.1-inch Dream Chip cameras up to 24MP that need a standard or tighter view (Computar 12mm or 16mm)
Not for
- 1.1-inch sensors if you pick the Kowa 5mm or 8mm; their image circles are too small
- Cameras above 5MP if you need full sharpness from the Kowa 8mm
- Low-light lines if you choose an f/2.8 Computar without enough illumination
