These pictures are a $2 bill taken at 50mm focal length with a shooting distance of about 20 inches. The full frame shots are resized to 1024X768 and compressed. The crops are not resized or compressed.

Kit lens full frame of $2 bill

Kit lens crop of $2 bill

50mm lens full frame of $2 bill

50mm lens crop of $2 bill

Sigma 28-80mm lens full frame of $2 bill

Sigma 28-80mm lens crop of $2 bill

These pictures are of a large needlework piece (33" X 25") taken at a shooting distance of about 66 inches

Kit lens full frame of needlework

Kit lens cropped image of needlework

Sigma 28-80 lens full frame of needlework

Sigma 28-80 lens cropped image of needlework

And now for comparison two dollar bill taken with a Minolta D7Hi at 90mm focal length and f8 and the Nikon Kit lens at 70mm.

D7Hi shot of $2 bill

Kit lens shot of $2 bill at 70mm