Lenses, M X V symbols

**Naomi Dines** · 9-Nov-2003, 10:18

Could anyone tell me what the M X V symbols on vintage Schneider lenses mean? Some of the lenses I have been lent have the lever glued in one position... I would like to know how / why to set them, and how they influence the alternative (green) f-stop and focal length numbers on the lens.

Many thanks

**John Cook** · 9-Nov-2003, 10:26

I can give you part of the answer. The X is for flash sync with electronic flash which reaches maximum intensity almost immediately. M is for syncronizing the shutter with flashbulbs which take time for the filament to heat and begin to glow. At this setting, the shutter remains closed for a short while until the bulb has reached maximum brightness.

Not sure about the V. But bulbs used to be available for use with focal plane shutters which burned differently from regular flashbulbs.

Can't recall the use of the green numbers, unless it is a convertible lens with a removable element.

**Bob Salomon** · 9-Nov-2003, 10:44

V is the self timer. Sounds like you have an old Synchro Compur shutter.

The symbols are onm the shutter and not on the lens.

**Jason Greenberg Motamedi** · 9-Nov-2003, 10:55

the green "alternative" f/stop numbers are for the lens when converted by removing the front element.

see: http://www.schneideroptics.com/info/faq/large_format_lenses/#q13

Unless you are using flash BULBS use the X setting.

**Naomi Dines** · 9-Nov-2003, 12:39

thank you so much, that helps to clarify things enormously, and so quick too...

what a great resource this, and all of you are!

**Neal Shields** · 9-Nov-2003, 13:53

You may not want to try out the self timer feature. I have had some old shutters that it would go about half way and then stop and as I remember, you then couldn't use the shutter at all till you opened it up and cleaned it out.

**Ernest Purdum** · 9-Nov-2003, 19:35

"V' stands for vorlauf if anybody cares and I don't know why they should. Neal, excellent advice about not trying it out. Sometimes it happens by accident, though. I've had some success holding the shutter perpendicular to my arm and rotating my wrist a few thousand times. No guarantees, though.

**Emmanuel BIGLER** · 10-Nov-2003, 11:25

Ernest : let me care for that ;-);-) V stands for "Vorlaufwerk". The german word 'Werk' is also used in horology to denote a watch mechanism. Here it means a separate self-timer escapement mechanism. Vorlauf, means litterally 'running before'.