Above: The Mobius ActionCam opens with two screws. One more set screw and you can expose the IR filter.
To convert a Mobius ActionCam so it captures near infrared photos requires opening the camera and removing the IR block filter. Of the half dozen cameras I have converted, the Mobius is by far the easiest to open, but removing the IR filter is really hard. What I had read and heard about the Mobius didn't prepare me for the job. There are good instructions for opening and refocusing the camera, but I did not find good instructions for removing the IR filter.
- Loosen two screws to open clam shell case.
- Scratch line across the sensor unit and the lens to mark focus point.
- Loosen set screw.
- Pry up sensor/lens unit.
- Unscrew lens ~12.4 turns to remove it.
- Place camera in safe place.
- Find the IR block filter on the rear end of the lens and bust it to smithereens.
- Clean rear lens element of glass fragments.
- Screw lens back on sensor unit and align focus scratches.
- Replace sensor/lens unit in case.
- Tighten set screw (or not).
- Close case and tighten two screws.
Two small Phillips head screws open the case, exposing the sensor/lens unit and the tiny set screw that must be loosened. The threaded lens will be removed by unscrewing it from the sensor unit. Loosen the set screw before you lift the sensor/lens unit from the case to reduce stress on the ribbon cable. Some Mobiius cameras apparently ship with an Allen wrench for this set screw, but mine didn't. When the set screw is loose (just a little so it can't fall out), the sensor/lens unit can be pried up (see illustration here).
Without yanking on the ribbon cable, unscrew the lens and count the number of complete turns (mine was 12.4). Now the lens can be worked on and the rest of the camera can be put in a safe place. The reddish IR block filter is glued to the rear end of the lens unit. The only way I could remove it was to break it into many shards of glass and lots of glass dust. The dust mostly fell onto the rear lens element and would not blow off. My camel's hair brush just smeared something on the lens, so I had to clean it with lens cleaner. It was the messiest IR block filter removal I have done.
After I screwed the lens back into the sensor unit, I did not tighten the set screw all the way. This allows the lens to be focused without opening the camera. The factory focus point is great for anything about seven feet or farther from the camera. To photograph plants up close, the lens can be rotated counterclockwise just a little. If the set screw is not too tight, this can be done using the notches on the front lens housing that just show when the camera is assembled. You will want to scratch the front of the lens so you can see where the factory focus point is.
The scratch at six o'clock on the front of the lens is at the factory focus point. By rotating the lens a few degrees counterclockwise, the lens will focus at about three feet (yellow arrow) or at about seven inches (green arrow). The lens can be rotated with a sharp object inserted into one of the notches around the lens housing.
I now have a full spectrum Mobius camera which takes really weird photos. Using the Mobius Filter-O-Matic, I can try different filters to learn how to make the best plant health images.