Can't tell you where to find the manual, but here is an explanation in Google's best Japanese translation of the difference.
Home > Products > Strobes > Inon Z-220F
PRODUCTS
DSLR Cameras
DSLR Housing
Compact Cameras
Compact Housing
Wet Lenses
Strobes
Video Lights
Trays & Arms
Spare Parts
Inon Z-220F
" As the Strobo for film camera, the INON-Z220 Strobo which is proud of the high performance which stands out changing minor, it is new sale as Z-220F. You could not use the revised point, so far the case of use with the digital camera and the like, forced illumination mode was added to the built-in focusing light/write. In addition target laser pointer function was removed. Also you can use with the digital camera with the manual modulated light function of 11 stages the silver salt not only. In this case, connection with the camera becomes only optical fiber connection and TTL modulated light is not possible but combined use with the film camera in the one which is thought it is the Strobo which you recommend.　G.N 22 illuminating angle 100゜x 100゜
Z-220F is the Strobo which basically is developed as the Strobo for the film camera. Therefore with the digital camera which has pre- luminous function in case of use G.N11 (1/2) at the light intensity below only in case of use it aligns radiates. Alignment to the FULL light intensity becomes possible with combined use of another sale accessory INON focusing light/write controller. In addition, TTL operates with in no case.
In connection with the camera housing optical connector cable kit of correspondence is necessary each in camera housing. "
Seems that the F model has replaced the laser pointer with a built in focus light. Used with the preflash on a digital, you only get half power unless you add the write controller in slave mode. If I read correctly, it will give full power in manual mode. Probably the "S" manual is close enough, though I've found all Inon manuals to be rather obtuse. Good Luck.
