Nice set
,
I prefer No. 1 as it shows the whole of the circle and that was the title. I do not like the foreground shadows and farm in the background for 3. The farm takes away the feeling of remoteness that 1 has.
No. 2 is a cracking picture of a rock
but it could be any rock. It is not obvious it is part of the circle.
BTW what is wrong with iso 200. Your camera cannot be that noisy
