UAS pilot reported flying at a distance where they lost VLOS with the UAS.

Narrative

I was operating my Mavic Mini with strobe lights on the rear motor arms. The flight take off was from public roadway exit ramp (~1 mile from facility) adjacent to a large farm field. Wind 6 mph 253 degrees SSW; 34 degrees F; cloud cover at about 1;400 ft. Initial straight-line flight directly to the East; starting at about 12 ft. extending to 60 ft. at a distance of 1;600 ft. from the Home Point. The flight was kept low to the field; with a stand of trees in the distance to provide contrast; to experiment with the maximum VLOS (Visual Line of Sight) distance under optimal conditions. Height was adjusted to match the contour of the field elevation and stay low to the ground. Just as reaching the maximum VLOS; I noticed a half-dozen or so white deer tails; running; in the iPad mini display. The altitude was increased to 145 ft. to avoid too close a proximity to the deer. However; I followed what was a herd of 15 to 25 deer into the next field; at a final distance of about 2;700 ft. (recorded in AirData). At this point navigation was directly from the display in DJI Fly. Essentially; the enthusiasm for a video opportunity gained control of decision making.