Can Noblex filters be attached without wasting film?

I have a Noblex 135S camera. Is it possible to mount a filter without any light exposing the film while doing this? It seems that when the lens is positioned to put on the filter it is now allowing light to pass through on to the film since there is no shutter blocking this from happening. This means one frame is wasted when the filter is attached and another when it is removed - the Noblex instruction manual doesn't say anything about this. I'd appreciate hearing from Noblex owners who can confirm this or know of how to mount a filter without wasting film. Thank you.

On the 6/150, you shut down the power, press the shutter release and turn the drum backwards. The shutter does not open.

Dante

Thanks for your response Dante. I believe that when you do as you suggested the drum should only turn back until it reaches a halt with the lens appearing on the right side of the camera. My camera does this when it is level or pointed downwards and the shutter does indeed stay closed as it should.

But for some reason when my camera is pointed upwards I can repeat this process and the shutter will be open allowing the drum to revolve backwards for the entire rotation while causing an accidental exposure on the film. This is obviously not what it’s supposed to do and that’s where my initial confusion came from. Other than that my camera seems to be working perfectly.

Old thread, but it's an old camera so I thought I'd post this just in case it helps someone...

There's actually a key step missing from the English-language user manual, which exists in the German-language manual. As AdrianW discovered, before you press the shutter release in order to manually rotate the lens drum, you need to point/lean/tilt the camera slightly forwards/downwards first. If you listen carefully as you do this, you can hear something falling into place inside the camera. I believe whatever is happening here is some kind of "lock" that falls into position, to stop the drum from rotating too far, or maybe to (also) block the aperture. If you do this, the lens drum will only rotate far enough to just access the slit, so you can insert/remove the filter without exposing any film.