M sync

[flashbulbman]

Just got my 150mm CF Sonnar in the mail. I like it much better than the chrome model I almost bought. HOWEVER, there is no M sync lever on it like the one on my chrome 50 Distagon. Does this mean I can only use flashbulbs at 1/30th of a second or slower? I can sync them much faster on the old chrome lenses.

 

[Victorh]

Black

If it is just black you want why not go for this lens:





Zeiss stopped offering a self timer and the possibilty to adapt the flash sync for bulbs with CF lenses.





On some C series lenses the XMV selector was simply blocked by two small screws to avoid accidental shifting from the often preffered "X" position.


Vic.

 

[stever]

There is not reason to use an M sync with an M bulb with a leaf shutter. The M synch is used for a focal plane shutter and burns brightly for a relatively long time so that the slit has time to cross the focal plan. I am leaving out the discussion of the fast rise time and number of millisecond of relatively flat but bright burn. It does not matter for a leaf shutter.

An X synch with a leaf shutter will synch for all speed up to 1/500 second with any C, CF, CFi or CFE lens. The guide number for a strobe will give the f/stop which can be used at any shutter speed because the strobe flash is so short that it will complete fit in with all leaf shutter speeds.

Steve

 

[Victorh]

There is not reason to use an M sync with an M bulb with a leaf shutter. The M synch is used for a focal plane shutter and burns brightly for a relatively long time so that the slit has time to cross the focal plan. I am leaving out the discussion of the fast rise time and number of millisecond of relatively flat but bright burn. It does not matter for a leaf shutter.



Steve

I do not see why Zeiss/Hasselblad would have made C series lenses with M sync for focal plane shutters.
These lenses can not be used with early Hasselblad bodies with focal plane shutters.
The 500 system with leaf shutters was introduced in 1957.
The first focal plane cameras that were suitable for C series lenses were launched in 1977.

The M setting triggers the flashbulb as soon as the shutter starts to open.
That gives the bulb time to ignite.
The bulb is fully ignited by the time the shutter is completely open.
M setting should be used with bulbs for all shutterspeeds from 1/30 second and faster.


Vic.