Wirelessly posted (BlackBerry9000/4.6.0.167 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/102 UP.Link/6.3.0.0.0)

Tubes do make a huge difference in reduction of depth of focus and minimum focusing difference. I have the number one tube (45mm) for my RB67. On a regular old Sekor 90mm lens. Really does make a difference.