http://zone-10.com/tope2/main.php http://zone-10.com/tope2/main.php?g2_itemId=20742 20742 f7.5 - Wide Open http://zone-10.com/tope2/main.php?g2_itemId=20745 20745 f16 - Best aperture for sharpness ! http://zone-10.com/tope2/main.php?g2_itemId=20748 20748 f32 - Degraded by diffraction http://zone-10.com/tope2/main.php?g2_itemId=20737 20737 Setup for test images. E-P1, OM adapter, OM bellows, OM 7mm extension tube, Busch-BIs-Telar http://zone-10.com/tope2/main.php?g2_itemId=20740 20740 Close-up of lens