VL53L1X Accuracy Issue with Dark Clothing , Should I Switch to VL53L5CX?

[Basil]

Hi,

I'm working on a people counting system using the VL53L1X in multi-zone mode with a single sensor. It works well in general, but I'm seeing accuracy issues when people wear black or dark clothing—likely due to low reflectivity.

I’d appreciate some guidance:

• Would the VL53L5CX provide better detection for dark clothing?

• Does it handle low-reflectivity surfaces more reliably?

• Or would it be better to use multiple VL53L1X sensors?

• Any other sensor recommendations for more reliable people detection?

Thanks in advance!
Basil

[John_Kvam]

Basil - 

the VL53L5 is one choice, but a better idea would be to go with the VL53L8CX. 

The L8CX has better optics that allows a more powerful VCSEL (Laser) output. 

And because ST actually makes the optics out of Silicon Wafers, the cost for the L8 is the same as for the L5. 

So you get a better sensor - which will detect people to a greater distance - for the same price as for the VL53L5.

It is unfortunately more costly than the L1CX, but worth every penny. I'm sure it will do what you need.

- John (ST Retired.)

[Basil]

Hi John,

Thank you so much for the helpful recommendation!

Just a quick follow-up: For a bidirectional people counter, would the VL53L8CX alone be sufficient to reliably detect direction as well, or would I still need to combine it with another sensor (e.g., another ToF or ultrasonic) to improve accuracy?

Also, are there any limitations or considerations I should be aware of when using the VL53L8CX for bidirectional counting—especially in high-traffic or low-reflectivity scenarios?

Additionally, would you recommend any specific mounting orientation or zone configuration that tends to work best for tracking directional movement?

Appreciate your insights!

Best,
Basil

Sensors like the VL53L1X can struggle with dark or absorbent materials because they reflect less light, which can affect measurement accuracy. Upgrading to the VL53L5CX may improve readings, but adjusting the environment or testing different surfaces often helps as well. Fabric color and texture play a significant role in how light-based sensors respond. Examples of fabrics with varying reflectivity can be found in a wide selection of clothing materials at the end of this page.