Sky Quality Meter comparison
Field of view (FOV):
It is desirable to have a narrow field of view when determining the sky brightness in crowded areas where street lamps, buildings, trees, etc. are present. A more accurate view of a small area of the sky can be found with a narrow FOV. Here is the FOV comparison chart from experimental readings. Here is a visual FOV comparison chart.
The wide FOV meter is best suited in wide open areas where there is a clear view of the night sky.
In some wildlife studies where a creature is affected by the whole sky, the wide angle model may be more suited for single readings. Multiple readings using the narrow FOV unit can be combined for the same effect.