There is only one small date variety in 1828, N-10. on the large dates the 8's are what are called block 8's and are one oval set on top of another and section between the ovals is very thin. The small 8 is formed like an S with a wide diagonal band between the top and bottom and the ends of the "S" are "closed. Here are pictures of a large and small date 1828.
Large Date N-2

Small Date N-10 Note the wide diagonal across the center of the 8's
