sharpest aperture http://www.adorama.com/alc/taginfo/sharpest aperture Article: Close-ups: Getting a Sharper Image.How to shoot up close and get tack-sharp results <p><span style="font-size: small;">The biggest challenge photographers face when shooting nature close-ups is how to get a sharp image. </span></p> http://www.adorama.com/alc/article/13100