Learn How to Focus A Camera Lens from Our Optical Engineering Consultants.
Getting Started With Your Camera Lens Focus Process
1.) Find your Camera Focus Card
We include a focus card with the majority of our M12 Lenses and CS Mount Lenses. We suggest a minimum of 4 cards for the proper process.
The 2" FocusCard 36 has 36 square wave spoke line pairs and a contrast ratio of 80:1. This is a subjective focus tool and should not be used for objective eSFR measurements.
2.) Write Down the EFL + F#
You may find our Field of View Calculator of interest to figure out the FoV of your camera system
3.) Determine the Nominal Object Distance for your Camera
Consider all of the objects you intend to capture with your vision system.
What is the closest? What is the furthest? What is the median of the object distances?
Our Depth of Field Calculator will give you the hyperfocal distance of the sensor+lens combination. This is the maximum distance the FocusCard should be set.
4.) Prepare Your Camera Set Up
Set 1 focusing card in each diagonal direction 50% from the center to the corners.
You can move these around, but using only a single target in the center usually does not yield optimal focus across the image.
We recommend using a neutral gray background to minimize auto-exposure clipping.
5.) Start Your Camera. Go Past Focus. Come Back.
Open a real-time output stream from the camera. Refer to your camera manufacturer for details.
Clean your sensor, lens threads, lens mount threads, and lens rear surface using an air dust tool. Slowly thread your lens into focus. Go a 1/4 to 1/2 of a turn past focus.
After the lens starts going out of focus, return to best focus using 1/16 turn increments. This process reduces the chance that you are not at the best focus.
Return to your console and have fun with computer vision. If you have challenges and are using our lenses, please contact us more advice.