I think I've already replied to you on Facebook, but I'm going to paste the reply here hoping that it is useful to whoever stumbles upon this thread:
Physical distance: Always make sure that you've printed out the target in regards to the precise physical distance. The distance should be measured from your sensor's lense, rather than from where you stand (taking into account the fact that your hand/gun will cut the distance during the actual practice session)
Also, for your MX-02 (as well as for MX-W2): make sure that the position of your focus ring is set to that physical distance.
Thus, you need to get the slider (highlighted on the screnshot below) pointing at 4, as your daughter is training at 4 meters.
Background: If we are talking home practice, it's far better to stick your paper target to a white wall. Sometimes darker walls are detrimental to the sensor's FOV, since it has to see more white "blank" around the target's black circle.
Lighting: I highly recommend using only flicker-free LED lamps with "warm" spectrum (2700K), incandescent lights or any standard halogen lamp to ensure that not only your SCATT sensor can easily detect the target but also so that your eyesight is safe during every training session. By the way, you can utilize LUX Meter (a free app) to measure the intensity of your lighting with your smartphone We recommend to have at least 1000 LUX evenly spread across the face of the target (so no dark spots, shadows and whatnot)
For instance, this one here looks like solid 1000-1200 LUX
This thing attached below is an
Iris diaphragm
It's designed for outdoors to offset extreme sunlight conditions.
Generally speaking, it should
not be used indoors, for it interferes with the sensor's ability to see the target when excessive sunlight is not there.
Training on shorter distances: If you mount the sensor under the barrel, the parallax is far greater.
The closer you bring the two together, the less is the parallax you'll be getting at home on shorter distances.
Here is a pretty effective trick you can use to align your camera-based sensor's FOV with your gun's sights and decrease the parallax
at the same time - rotating the sensor to a 11 o'clock position (as shown below)