The lateral shift of the standard EMS-US/UM is 26.87mmX2.
So, the “D” at the IPD of 64mm is 117.7mm. (“D”=span of the OTAs)
Innovation of Astronomical Telescope
正立ミラーシステム(EMS)を開発した松本龍郎のサイト。 たった2回の反射で天体望遠鏡の像を正立像にします。
Tatsuro Matsumoto; Inventor of the EMS, Erecting Mirror System. EMS offers non reversed upright image with no additional undesirable abberations.