I'm staying on the zero range, which is entirely in shade, the scope is placed outside in the sun... so i'm not subject to the changes in heat. At the end of the test, once it
cooled in the shade, it was back on.
The light meter was on a close target, considering it's my 1ds, i'd say pretty accurate... i could have taken a second, but didn't feel the need
On closer ranges, there was less of a shift, it was perhaps 2-3mm at 30, 2 at closer ranges, perhaps 1 at really close ones... i noted it, but didn't measure specifically, because the shift at 55 equated to less of a yardage shift as the gaps got wider as the ranges got shorter if you see what i mean... 4mm at 8yds is naff all
The sun only moved in an hour... it was behind, but never appeared on the target as it was in shade... sky was clear blue all the way through.