Originally Posted by Musoman
PS how did you mount the big VIV 6x7 Pentax MF TC ?
I removed the tube holding the glass and mounted it in one of those cheap screw together macro tubes. Best thing is that when the front bayonet section is screwed onto the macro tube, it clamps down onto the teleconverter tube making mounting it really easy. Front element is 1.25" dia and the rear is nearly 1.75" dia. See pics.