Hey everyone, I’m having trouble with my Arducam B0436 Mega 5MP SPI Camera Module. The lens is supposed to be manually focusable — that’s one of the reasons I bought it — but I can’t turn the M12 lens at all. On closer inspection, there’s this black glue-like substance between the lens barrel and the camera holder. Looks like it’s been glued in place at the factory. Has anyone else encountered this? Is this normal or did I get a defective unit?
That black glue is actually expected on these modules — it’s not a defect. Arducam applies it at the factory to fix the lens at a default focal position so it doesn’t shift during shipping and works reasonably well out of the box for general use. The camera absolutely does support manual focus, but you’ll need to free the lens from that adhesive first. Before we get into that, can you tell me a bit about your setup? What are you using the camera with, and have you tried any steps already?
Thanks for the quick reply. I’m using it with a microcontroller over the SPI interface — I bought it specifically for the SPI support. As for what I’ve tried: first I attempted to focus through software thinking maybe there was some register or command I could use, but no luck there. Then I tried to gently turn the lens by hand and that’s when I noticed the black glue holding it tight. I started wondering if I should try to unscrew the lens and scrape the glue off, but I’m worried about damaging the camera or the lens mount. Wasn’t sure if there was a recommended way to do this.
You’re on the right track — software-based focusing won’t help here because this is purely a physical adjustment. The M12 lens focuses by being screwed in or out of the threaded mount, so the lens barrel itself needs to rotate. Scraping the glue off without softening it is risky and I wouldn’t recommend it — you could damage the threads or the holder. The safer approach is to soften the adhesive with heat first. Here’s the procedure:
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Grab a hairdryer — a regular one on low-to-medium heat is usually enough and much safer than a heat gun. If you do use a heat gun, keep it on the absolute lowest setting.
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Hold the heat source about 5-10 cm away from the lens mount area, specifically where the black glue is visible between the lens barrel and the holder.
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Heat it for roughly 30-60 seconds, moving the heat source around the lens so the heat distributes evenly. You’re only trying to soften the glue until it’s pliable — not melt any plastic components.
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Once the glue has softened, grip the textured part of the M12 lens and gently twist it counter-clockwise. Don’t force it. If it doesn’t budge, apply a bit more heat and try again. It should break the seal without much resistance once it’s warm enough.
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With the lens freed, you can screw it in or out while viewing a live video feed to dial in the sharpest focus for your working distance.
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Once you’re happy with the focus, the lens should hold position from thread friction alone. If you want to lock it permanently, a tiny dab of non-permanent thread-locking adhesive works well.
That makes a lot of sense — softening rather than scraping. I was honestly about to go at it with a hobby knife and I’m glad I asked first. I’ll give the hairdryer method a try later today. Quick question though: is there any official documentation or a video guide for this? I searched before posting and couldn’t find anything about dealing with the glue on this specific module.
Good call holding off on the knife — that could have ended badly. As for documentation, you’re right that there isn’t a published guide or video for this specific procedure at the moment. This is a fairly standard step for anyone needing to refocus M12 lenses on Arducam modules, and our team has acknowledged that a support article or video walkthrough would be helpful. It’s on the radar to create one. In the meantime, the steps above should get you sorted. Let us know how it goes once you’ve tried the heat method — would be great to hear back.
Will do. I’ll report back once I’ve had a chance to try it. Appreciate the detailed walkthrough — the heating approach is not something I would have guessed on my own. Hopefully this thread helps others who run into the same thing.