Originally posted by Fl_Gulfer I'll stick with my Jessops Auto Extension Tube Set
I removed the glass elements from a Vivitar 2x TC, now I have a 25mm tube with auto exposure for $20. Since I use manual focus for macro shooting, it does the job, but a 3x would have been better because of the extra length. A 25mm tube with a 100mm 1:1 macro lens only gives me 1.2:1, less than a 1.4x convertor and considerably less than a Raynox 250 (approximately 3:1).
I intend to try the 25mm tube and 1.4x TC with the D FA 100mm macro to see how that combination works (1.7:1). I don't think I would benefit from AF tubes though, extreme macro is too tricky for auto-focus.