How to pick the perfect optical filter for machine vision

Is the optical filter in your device an afterthought?

Then you might be making a costly mistake. And while we understand that the optical filter is a seemingly humble – almost invisible – component, we’d like to show you the significant benefits of choosing better optical filters suited for your exact application within machine vision.

This brief blog showcases the main challenges and considerations you face when picking optical filters for your devices – and how the right solutions could benefit your next device.

Hopefully, it becomes clear that the optical filter is a critical component with the potential to improve the performance of your next device.

1. Your device reflects too much light, leading to misreading and slow performance
2. Your device is defenseless against potential vandalism in the public space
3. Your optical filter lets in the wrong wavelengths
4. Your optical filter does not let in enough of the needed wavelengths
5. You have chosen an optical filter unsuited for your application, which leads to an underperforming device
6. Your device has more than one sensor and unwanted light/reflections bounce between sensors

1. This challenge can be solved by adding an anti-reflective coating to your optical filter. Done right, this could minimize reflections from the normal 8% to as little as 1%.
2. If your device is meant to be placed in an exposed environment, an optical filter could function as a simple mechanical protection – and the filter can easily be replaced, costing much less than the expensive components behind it.
3. If your filter lets in the wrong wavelengths, you will experience too many misreadings and a low speed. The solution is to give your sensor better conditions to succeed by blocking unwanted interfering light.
4. If your filter does not let in enough of the wanted wavelengths, you will also experience misreadings and slow reading speeds. Here, the solution is choosing an acrylic with a very low signal-to-noise ratio.
5. To avoid ending up with an underperforming device that does not hit your target goals, you need expert knowledge of optical filters and strike the right balance between costs and your need to achieve certain speeds and margins for errors.
6. When you combine several sensors in one application behind an optical filter, you might gain performance optimizations by printing a shadow mask on the filter to delimit the different sensors, minimizing unwanted reflections across sensors.

Do you want to know more about the potential enhancement of your products with better optical filters?

We have written a brief guide with 3 steps to enhance your light sensing & scanning device with better-performing optical filters.

Download it here and take the next step towards market-leading machine vision performance!