Where to buy C, CS, and M12 mount lenses + info on IR capture

[bfree]

While ArduCam does sell lenses, their website makes it very difficult to search by mount, FOV, and IR cut/passthru.

I’ve been using UCTronics - which happens to be an ArduCam supplier/reseller:
https://www.uctronics.com/

@edward - If I get access to update ArduCam’s Wiki, I’ll update the following info there.

Mounts:
C - Fixed focus, 1" diameter w/ 32 threads/in
CS - Same as C except focusable
M12 - 12mm diameter; on older mounts/lenses, threading is not standardized
S or M12S - Same as M12, except standard threading: 0.5 mm pitch

Field of View (FOV)
May be provided as horizontal (HFOV), vertical (VFOV), or diagonal (DFOV or just FOV).
The FOV will depend on the sensor size, pixel pitch/resolution, and focal length/distance - as well as the lens.

Here’s a FOV calculator:

Camera Field of View Calculator | Advanced FoV Calculator

They also sell lenses, but apparently only visible light, not NIR-Pass/Noir lenses.

Approximations for M12 lenses:

> 100.4H 77.3V 110.5D  Wide ~15mm
   54.4H 37.8V  63.4D  Normal ~35mm
<  36.2H 24.6V  42.9D  Zoom ~55mm

Most lenses are assumed to be visible light only; IR is filtered/cut/blocked. Most sensors are sensitive to IR, even though our eyes are not - so if you are not filtering IR, your images will be tinted red and possibly a little washed out.

If you need to capture NIR (Near IR, as opposed to thermal), you need a lens that passes NIR frequencies: 750 to 2500 nm.

If you are doing night capture, you will likely need a NIR lamp. Some camera SKUs come with a pair of NIR lamps:
B003504 OV5647

You can also purchase such lamps separately:

Infrared LED Board for RPi Camera

Note: despite being invisible to the human eye, such IR lamps need to be rated human safe. If using an IR led-laser (with defractor - as opposed to a diffused lamp), it needs to be rated Class 1 to be safe.

If you need to record in daylight and at night, you’ll need a switchable IR-Cut filter:
B003504 OV5647 (105deg H-FOV)
B003507 OV5647 (140deg H-FOV)
B0154 IMX219 (100-150deg FOV)
B0270 IMX477 (C-Mount 65deg FOV)

Some SKUs come with a photo-resistor that automatically enables/disables IR filtering based on ambient light. The photo-resistor can be disconnected, and DGND/IR pins can be connected to ground and an available GPIO pin (ArduCam recommends GPIO4 pin 7). See my notes at:

B0425 (imx327) producing mechanical sound

@Robert - You don’t need to remove the photo resistor, unless you want to. All you need to do is disconnect the white connector with the red and black wires - that will leave the IR-Cut filter on (default daylight mode). If you want to control it programmatically, you need to find the ground (DGND) and IR pins on the opposite side of the board from the ribbon cable. The pinouts are different on the UC-755 rev C: 3V3 IR TRIGGER DGND XVS SIOC SIOD 3V3 The top 3V3 and IR pinouts are p…

Multi-Camera Adaptors
ArduCam indicates that they do NOT support cameras with switchable IR-Cut filters in their Multi-Camera Adaptors.

I’ve confirmed that while the following cameras do work on RPI OS and Ubuntu on Raspberry Pi4B, they do not work with ArduCam’s Multi-Camera Adaptors:
ArduCam B0424 IMX290
ArduCam B0425 IMX327
ArduCam B0423 IMX462
It appears that they simply need to update their driver, but will only do so for bulk orders.

While they’ve said they don’t support B003504 OV5647 on their multi-camera adaptors, they do support the OV5647; I’ve just ordered a pair of B003504 cameras to test this out.

STRUCTURED LIGHT
If you are doing structured light depth sensing, you’ll need a Class 1 led-laser and a high resolution random point defractor, rather than an IR lamp. These are difficult to find and often expensive.

I will post a separate topic on multi-camera IR setup, and possibly a post on structured light capture in the future.

[dp8ee6]

Absolute goldmine !! I bow before you.

could one just remove an ir blocking plate from those lens systems and make them allow IR ? Or is there IR filter coating on the lens itself ?
I am talking about M12 lens.

[bfree]

Any camera with a switchable IR-Cut filter will have a lens that passes IR frequencies.

Many of these cameras with switchable IR-Cut filters have photo resistors to automatically enable/disable IR filtering based on ambient light.

To make these switches manual or programmatic, you need to disconnect and/or remove the board’s photo-resistor. To make the switch programmatic, you need to connect the board’s DGND and IR pins to Ground and a free GPIO pin.

Arduino’s docs explain how to do this for UCTronics camera boards UC-350 Rev B:
https://docs.arducam.com/Raspberry-Pi-Camera/IR-Sensitive-Camera-with-IRCUT/quick-start/

However, IMX290/IMX327/IMX462 cameras have a UCTronics board UC-755 Rev C with a different pin out. I’ve posted instructions for this above, and here:

B0425 (imx327) producing mechanical sound

@Robert - You don’t need to remove the photo resistor, unless you want to. All you need to do is disconnect the white connector with the red and black wires - that will leave the IR-Cut filter on (default daylight mode). If you want to control it programmatically, you need to find the ground (DGND) and IR pins on the opposite side of the board from the ribbon cable. The pinouts are different on the UC-755 rev C: 3V3 IR TRIGGER DGND XVS SIOC SIOD 3V3 The top 3V3 and IR pinouts are p…

As for removing IR filters… you generally cannot remove IR filtering from a lens. The filter is either due to the composition of the lens glass, or applied as a film which can’t be removed without damaging the lens.

For switchable IR filters, you could remove or replace the filter mount, but it would be much easier to just disable or turn off the filter as described above.