Mamiya PRO 645-#2 winder & leaf shutter lenses

I just shot today with a newly purchsaed used 645 pro, not TL. I

have the #2 winder with cable to cock shutter on leaf shutter

lenses which i will refer to as LS. I put body shutter speed at

slow shutter speed, dialed in the shutter on lens to either 1/500

or 1/250, camera shutter on 1/125 or 1/60. I got a lot of half

frames- half of the image recorded on the film and half was cut

off. any idea why? what can i do to make it work? I wish i could

test for sync by taking off the back and looking thru the back of

the camera body. I set the camera body shutter release onto the

white dot, i dont think that was a problem. Is there something i

need to set or do to make the camera shutter open first and not

get in the way of my image? this is super frustrating. On the lens,

theere is that green "F" to the right of the shutter sppeeds. what

is that used for? I thought i could put it there when using the #2

winder, i had heard that at that point you just need to set speed

on camera body and it tells the lens shutter to shoot at that

speed?? My manual does not say how to do it. I had about half of

my shots ok and the rest with that half blocked image. Help!!!

how is it properly done? thanks, john

If set as you suggest in your post (1/125 second and Lens set to F) then half frames are

expected.

The "F" setting is for "focal" plane shutter. When set at F, the leaf shutter should NOT be

active. The focal plane shutter always fires.

With the winder(401) and cord attached to the lens, and the lens' shutter speed set

correctly, the camera should set the focal plane shutter to 1/8 second. (perhaps slower).

Try a few exposures at a higher speed setting on the body, then a few with the body speed

set to 1/8. This would test for the appropriate signal. If there is a difference (still getting

half frames) the cord or other connection may be bad. I don't know enough about the

electronics to know if something else would also be apparent.

Remember the flash synch goes to the proper shutter. The connection on the lens when

using that shutter, and to the body when using the focal plane shutter.

thanks, thats it. I had the focal plane shutter set at 1/60 at the

slowest, and had that problem half the time. Hope i dont get my

ass sued over this, my camera manual does not address this at

all! Thanks alot, will try a practice roll at 1/8 sec. No wonder my

flash did not go off when the lens was set at "F", it could not sync

at all with focal plane shutter due to that setting.