How to focus an event-based camera
Event-based cameras don't produce images and then can be puzzling when it comes to focusing.
If the scene the camera is looking at is static, no event will be generated and then no data will be output by the camera that makes the focusing difficult.
To focus your camera, you can use a tool provided in Metavision SDK or simply a blinking/moving image as explained in the following sections.
To focus your camera, you can use a tool provided in Metavision SDK or simply a blinking/moving image as explained in the following sections.
HW-related tips
EVK4 focusing
If you are using an EVK4 and have problem getting a proper focus, make sure that you inserted the C-CS adapter between the EVK4 case and the provided optic.
This adapter is provided in the EVK4 box.
This adapter is provided in the EVK4 box.
GenX320 CM2 module focusing
If you have purchased an EVK/RDK/OpenMV Cam or any other product featuring GenX320 CM2 module, then please note that its focus has been adjusted during the manufacturing process at a hyperfocal distance for GenX320 sensor (that is 8cm) allowing to be in focus up to infinity. However, during transport, the lens focus can be slightly changed, and then it needs to be re-adjusted manually.
To focus GenX320 CM2 module with its tiny M6-mount lens, you need to grab the lens by its notches and rotate it to slightly screw it in/out. For easier focus adjustment, we provide a focusing tool with its 3D model in the attachment to this page that can be 3D-printed.
Focusing procedure
Using Focus Adjustment tool from Metavision SDK
Prophesee offers an out-of-the-box application for Focus Adjustment. Learn more on Metavision SDK Docs.
Using a blinking chart on your device
Display "blinking.gif" on any screen (either your telephone or any computer screen)
You can right-click on the gif below to download it for your own convenience.
You can right-click on the gif below to download it for your own convenience.
- Place your camera at the target distance at which you need to be in focus (it should not be shorter than the Minimal Object Distance (MOD) of your lens).
- First, maximally open the aperture (if it can be adjusted) to obtain a smallest depth of field.
- Then, adjust the focus distance until the pattern in the center of blinking object is visible (especially in the region marked by red color on the screenshot)
4. Once the focus is good, adjust the aperture to obtain a needed depth of field.