For which value of omnidirectional_camera_aperture, the foot-bots can detect other robot's leds within 20 grids via omni-directional camera

For example If I used the following lines of code, to place the foot-bots, one at 5,22 and other at 21,22.
Code: Select all
<foot-bot id="kb" omnidirectional_camera_aperture="89">
<body position="5,22,0" orientation="0,0,0" />
<controller config="mrc" />>
</foot-bot>
<foot-bot id="kb-1" omnidirectional_camera_aperture="89">
<body position="21,22,0" orientation="0,0,0" />
<controller config="mrc" />>
</foot-bot>
Then by using the value of aperture=89 both are detecting each other as shown in below image.
But If I use the value of apperature=80 for the same robots then these robots don't detect each other via omni-directional camera. Why they don't detect with aperture = 80?
Second question is that, If I use the aperture=89, and now I place these two robots at 5,22 and 22,22, then now in this case these two also don't detect each other. In simple words, with aperture=89 we can detect the robots maximum at distance of 16 grids as can be seen in above attached image. With which value of aperture we can increase the detection of omni-dirrectional camera upto 20 grids?
Thanks