Dash Cam Aperture: f/1.6 vs f/1.8, Which Is Better?

What aperture means on a dash cam

Aperture is the opening inside the lens that controls how much light reaches the image sensor. It is expressed as an f-number, such as f/1.6 or f/1.8. A lower f-number means a wider opening and more light reaching the sensor. A higher f-number means a narrower opening and less light reaching the sensor.

Virtually all dash cams have a fixed aperture. You cannot stop down the lens the way you can on a mirrorless camera or a DSLR. The aperture is matched to the sensor and the lens focus at the factory, and the camera is designed to work well across normal driving conditions. If you see f/1.6 or f/1.8 in a spec sheet, it tells you how much light the lens can gather at its widest setting, which is also its only setting.

A wider aperture is one reason some cameras perform better on dark roads. It is not the only reason, but it is a useful spec to understand before you choose a camera. For more background on how the lens and sensor work together, see lens aperture and sensor size.

How f/1.6 and f/1.8 compare in low light

The practical difference between f/1.6 and f/1.8 is meaningful but not dramatic. An f/1.6 lens has a wider opening, so it lets in more light than f/1.8 in the same conditions. That can help the camera keep shutter speed reasonable and reduce the amount of noise in night footage.

For a driver who spends most nights on streets with streetlights, f/1.8 is often enough when the camera has a good sensor and solid image processing. For a driver who regularly travels on rural roads, highways without lighting, or parking lots in dark areas, f/1.6 gives the sensor a better chance to produce a usable image.

Do not judge a dash cam by aperture alone. A well-tuned f/1.8 camera can look better than a poorly tuned f/1.6 camera. The sensor, the lens glass, the bitrate, and the camera's low light processing all matter. Traffic safety organizations like IIHS, CDC, and GHSA track crash data and driver assistance trends, and their research helps explain why clear night footage is so valuable for reviewing incidents after the fact.

Here is a simple way to compare the two apertures:

Depth of field: why it matters less than you think

A wider aperture also affects depth of field, or the range of distances that appear acceptably sharp. In general, f/1.6 gives a shallower depth of field than f/1.8. That means objects outside the focused zone can blur more quickly.

For dash cams, this is less of a concern than it sounds. Dash cams use wide-angle lenses and are usually focused at a distance that keeps both the road ahead and nearby vehicles reasonably sharp. The field of view is designed so the area directly in front of the car is the priority, not artistic background blur.

If you are choosing between f/1.6 and f/1.8, depth of field should rarely be the deciding factor. Both apertures are wide enough to help in low light, and both can produce footage that is acceptably sharp for license plate reading and incident review. The camera's focusing system, lens quality, and mounting position usually have a bigger effect on overall sharpness. A camera with a fixed-focus lens that is set correctly will outperform a wider aperture lens that is not optimized for the vehicle.

What to look for beyond aperture

Aperture is one part of the low-light equation. The image sensor matters just as much. A larger sensor with larger pixels can collect more light, and a newer sensor generation usually has better noise control. If a camera has f/1.6 but an older sensor, it may still struggle at night compared with an f/1.8 camera built around a newer sensor.

Lens glass is also important. A plastic lens can soften the image, while a glass lens with good coatings can reduce glare and ghosting. This is especially noticeable when headlights and streetlights are in the frame. See lens material for more detail.

Video processing and compression also play a role. A camera that records a high bitrate preserves more detail in dark areas. High dynamic range, or HDR, can help balance bright headlights and dark shadows. If you want better night video, look for a camera that combines a wide aperture, a modern sensor, a good lens, and sensible processing rather than relying on f/1.6 alone. You can compare models with these features in the best night vision dash cams guide.

• Sensor size and generation
• Lens material and coatings
• Bitrate and compression
• HDR or WDR processing
• Fixed-focus accuracy

Which aperture should you pick?

Start with your driving environment. If you often drive after dark on roads without good lighting, f/1.6 is the safer choice because it gives the sensor more light to work with. It can make the difference between a dark, noisy clip and a clearer recording when a plate or a road sign needs to be read.

If you drive mostly during the day, in the city, or on well-lit highways, f/1.8 is a perfectly reasonable choice. The slightly deeper depth of field can help keep a wider area sharp, and a quality f/1.8 camera will handle most conditions well. The gain from f/1.6 is smaller when the scene is already well lit.

For most drivers, the best approach is to choose a camera with a solid overall low-light package instead of chasing the lowest f-number. That means looking at the sensor, the lens, and the processing as a whole. If a camera lists f/1.6, treat it as a small advantage. If it lists f/1.8, do not automatically cross it off your list.

You can narrow down the field with the best 2K dash cams, best 4K dash cams, or best 1080p dash cams guide depending on the resolution you want.

What to pick for your use

Questions

Is f/1.6 much better than f/1.8 in a dash cam?

No, the difference is modest. f/1.6 lets in more light, which can help in dark conditions, but it is not a huge leap. Sensor quality, lens glass, and image processing often matter more.

Does a wider aperture make dash cam footage blurry?

Not necessarily. Dash cams have fixed-focus lenses that are usually set so the road ahead stays sharp. A wider aperture like f/1.6 can reduce depth of field slightly, but at typical dash cam focal lengths the effect is small.

Should I choose f/1.6 only for night driving?

f/1.6 is most valuable for night driving, but it does not hurt during the day. Some cameras with f/1.6 may need good exposure handling to avoid overexposure in bright sun, so check reviews and sample footage if possible.

What else affects low-light performance in a dash cam?

The image sensor, lens material, bitrate, HDR/WDR processing, and the accuracy of the fixed focus all affect nighttime image quality. A camera with f/1.8 and a strong sensor can outperform one with f/1.6 and a weak sensor.

Can I change the aperture on a dash cam?

No. Dash cams use fixed-aperture lenses, so you cannot adjust the f-stop after purchase. You have to choose the aperture that best matches your driving needs when you buy the camera.