Inno-maker IMX462 v2

I’ve been testing the Inno-maker IMX462 camera for several experiments over a period of multiple years. It’s a sensor targeted for low light conditions, offered at a low price, and given those features I found that it’s a valuable alternative to the stock Raspberry Pi cams. I also found the image quality sometimes is lacking especially when using it in the low-light conditions where it should actually excel. I’ve dived into some of the details on how we can improve the image quality and found some nice tricks along the way. Recently I decided to ask the manufacturer if they were aware and if they would revision their product in the future. You never know right… But as it turned out, Inno-maker was already aware of some of the issues that I found and actually they already did have a new revision out there. To quote their words:

Thank you very much for the detailed explanation provided in your blog. We truly appreciate the effort you put into documenting your findings. May I know roughly when you purchased our IMX462 camera module? We already solved this issue around the middle of last year by replacing the LDO. The older versions indeed had this problem.

My camera board is bought in 2023 so unfortunately I’m using on of those affected boards. Inno-maker was kind enough to send the newer revision board in order to compare it to the older one. So here I am again, testing the image quality of the Inno-maker IMX462, but this time using the latest revision with LDO fixes.

Left: Inno-maker IMX462 old rev (modified), right: new rev

Left: Inno-maker IMX462 new rev, right: old rev (modified)

The tests are as following. I started comparing with the stock lens which contains an IR filter, and then took several pictures with different kind of exposure times (10ms, 100ms, 1s, 10s) and different kind of gain settings (0, 49, 98). I can added an IR light source (3 IR LEDs) and repeated the same process. Afterwards I swapped the stock lens with one where I’ve removed the IR filter from, and redid all once again.

All pictures were taken in Low Conversion Gain mode, which is the default in the linux kernel. Next I’ll share the pictures as I’ve obtained them, no image editing has been done (not even rotation).

stock lens with IR filter, no IR leds

shutter 10ms – gain 0

shutter 10ms – gain 49

shutter 10ms – gain 98

shutter 100ms – gain 0

shutter 100ms – gain 49

shutter 100ms – gain 98

shutter 1s – gain 0

shutter 1s – gain 49

shutter 1s – gain 98

shutter 10s – gain 0

shutter 10s – gain 49

shutter 10s – gain 98

stock lens with IR filter + IR leds

shutter 10ms – gain 0

shutter 10ms – gain 49

shutter 10ms – gain 98

shutter 100ms – gain 0

shutter 100ms – gain 49

shutter 100ms – gain 98

shutter 1s – gain 0

shutter 1s – gain 49

shutter 1s – gain 98

shutter 10s – gain 0

shu tter10s – gain 49

shutter 10s – gain 98

modified lens without IR filter, no IR leds

shutter 10ms – gain 0

shutter 10ms – gain 49

shutter 10ms – gain 98

shutter 100ms – gain 0

shutter 100ms – gain 49

shutter 100ms – gain 98

shutter 1s – gain 0

shutter 1s – gain 49

shutter 1s – gain 98

shutter 10s – gain 0

shutter 10s – gain 49

shutter 10s – gain 98

modified lens without IR filter + IR leds

shutter 10ms – gain 0

shutter 10ms – gain 49

shutter 10ms – gain 98

shutter 100ms – gain 0

shutter 100ms – gain 49

shutter 100ms – gain 98

shutter 1s – gain 0

shutter 1s – gain 49

shutter 1s – gain 98

shutter 10s – gain 0

shutter 10s – gain 49

shutter 10s – gain 98

analyses

First things first, simple physics do apply here:

• increasing the exposure time helps in capturing details in low light conditions
• increasing gain helps in low light condition when you want to restrict the exposure time, but brings lower quality images as a result due to noise

That being said, as you notice the pictures turn out a bit red-ish. This is due to the PI its power LED being roughly the only source of light directly pointed to the target background in a completely dark room. This assumption gets confirmed as soon as I switch on the IR LEDs. The latter easily outshines the power LED. The IR light appears a bit white-ish compared to the reds from the power source. We see this confirmed for the 10s exposure shots with the stock lens (with IR filter), when you compare the pictures with or without IR led. The images are still unedited, except for rotation.

left: IR LEDs + power LED active, right: only power LED (10s shutter – gain 49)

But the impact is huge when we repeat that shot without IR filter.

left: IR LEDs + power LED active, right: only power LED (10s shutter – gain 49)

The change in overall brightness is so huge that the image even gets over-exposured! So if you’re looking into nightly security applications I highly recommend removing the IR filter plus adding a IR light source as it will allow to capture dramatically more details! It even allows us to set the shutter to 100ms and still see details in the room’s background, which when repeated for the other LED/filter combination is simply not possible.

But the most important question here is: how is the quality when we start increasing the gain. Let’s widen the image up for some detail:

shutter 10s – gain 98 – stock lens – no IR light source (only power LED) – LCG mode

At those high gain settings it’s perfectly natural that we get noise added to our image. But what I find important here is that we see no banding at all. Okay, you may say there the most left side of the picture is a lot less bright than the right side, but that’s due to the power LED being blocked by that clamp that holds everything in place. It’s just shadow casted over the background, but it does indeed looks it bit weird this way. Now remember one of the picture I took in the past, with IMX462 from the first batch…

IMX462 v1 – shutter 100ms – gain 98 – modified lens – IR light source (only power LED) – LCG mode

And compare that with the same image lens, IR source, exposure and gain settings on the PI 2 that I’m currently using for the current tests:

IMX462 v2 – shutter 100ms – gain 98 – modified lens – IR light source (only power LED) – LCG mode

Although the lightning setup may differ over the tests back than and now, what’s important here is that we don’t see any of those banding issues here anymore!

Is Wifi impacting the analog picture quality? Let’s test:

shutter 10s – gain 98 – stock lens – no IR light source (only power LED) – LCG mode

Again the lighting may have been slightly different to previous tests, like the standby LED of a new device in that room, but in general we again see that there is no banding at all, even with the gain at its maximum level.

Conclusive thoughts

Left: Inno-maker IMX462 new rev, right: old rev (modified)

As it turns out, the Inno-maker IMX462 has become an even better alternative for lowres Raspberry Pi cameras, specially outperforming the Pi cams in low light conditions. It offers good value for superior night sight, and now with the new revision some of the pains of the first revision has been tackled. So if you’re still looking for a good bang-for-back security sensor, the Inno-maker IMX462 may be your board of choice.