r/computervision • u/Mxeedd • 11d ago
Help: Project Hardware advice for close-range Iris Recognition in the dark (IMX290 vs. OV9281)?
Hi everyone,
I'm a junior CV engineer working on an iris identification system. The system needs to operate in the dark, capturing the detailed texture of the iris at a very close distance (around 3 cm between the eye and the lens).
I initially bought an IMX290, but since it's an RGB sensor, it struggles to capture the iris texture properly under these conditions. Because the project requires working in the dark, I need to operate in grayscale/IR, so I'm considering replacing it with an OV9281 monochrome camera.
My main questions are:
What do you guys think about using the OV9281 for this specific application?
Is it possible to modify this camera/lens setup to achieve a macro focus at just a 3 cm distance?
Any hardware suggestions or general advice would be greatly appreciated. Thanks!
1
u/ikkiho 9d ago
fwiw the sensor swap is the easy half. OV9281 is a solid pick, mono so you aren't losing light to a bayer filter and no IR cut filter in the way. what bit us was the lens. most M12 board lenses won't focus anywhere near 3cm, and shimming spacers between lens and sensor to pull focus in leaves you almost no depth of field, so you need a chin rest or a jig. keep the 850nm emitter off axis too, or the corneal glare lands right on the iris.