M7 Rewind Crank Question

[Levpush]

Advertisement (gone after registration)

Hi friends, I just got myself an M7 and this is the first time I use a Leica film camera so please excuse me if the question sounds stupid. My question is about the rewind crank. When I load up the film and advance it, the knob turns with the advance lever as intended. However, I feel the knob seems loose and I can easily wiggle with it, is it normal? I dared myself and actually took out the crank and slowly turn it on the arrow's direction for about half circle and I don't feel it to lock somewhere to prevent me from doing so but I do feel some tension when turning. Is this normal or you suspect there could be something wrong? Thanks in advance. 

[trisberg]

Hi, what you describe sounds perfectly normal. Enjoy the new camera.

-Thomas

[Levpush]

7 minutes ago, trisberg said:

Hi, what you describe sounds perfectly normal. Enjoy the new camera.

-Thomas

Thanks Thomas, I’m wondering if it could be a problem that the knob doesn’t lock as it might accidentally unwind the film when the camera is on the go or somehow the person unintentionally turn the knob?

[earleygallery]

No it can't lock, it's normal, stop fiddling with it and just shoot pictures!!

[Levpush]

1 hour ago, earleygallery said:

No it can't lock, it's normal, stop fiddling with it and just shoot pictures!!

Thanks. I am shooting with it. Just want to know the camera better and satisfy my curiosity

[Chuck Albertson]

It doesn't lock, it turns as you advance the film, which tells you that you loaded the film correctly. You can't rewind the film without flipping that little lever on the front of the camera, so there's no danger of rewinding the film by simply carrying the camera around.

[250swb]

Advertisement (gone after registration)

On 6/26/2022 at 12:09 AM, earleygallery said:

No it can't lock, it's normal, stop fiddling with it and just shoot pictures!!

When you load a film the sprocket holes in the film engage in the gear teeth that are visible through the rear door when you load the film. The gears can only rotate forwards as you wind the film on and can't rotate backwards, until that is you decide to rewind the film and press down the rewind lever which disengages the gears. 

[adan]

Just as a reminder, the film itself is what "connects" the rewind knob to the wind mechanism/sprockets.

The film is NOT tightly packed in the cassette, nor tightly wound to be a "firm" connection - unless the photographer does that themselves (and not really a good idea; tightly packed/tensioned film is prone to each layer scratching the next if any dust or grit gets in).

Therefore there is (and should be) quite a bit of "play" and looseness at the rewind end (as a result of how the film doesn't fill the cassette, not the camera engineering).

As an idea of how loosely the film fills the cassette normally (24 or 36 exp. rolls), at one point Ilford reduced the weight/thickness of the plastic film base slightly, and was able to pack 72 exposures into a regular 35mm film casette. For the motor-drive users.

https://www.worthpoint.com/worthopedia/72-exposure-roll-ilford-hp5-1884239511

And indeed that film was so tightly packed that scratching became a problem.

So there is a lot of "spare room" with normal rolls, which the film is free to "unravel within" without affecting the correct advancing function.

[Chuck Albertson]

6 hours ago, adan said:

As an idea of how loosely the film fills the cassette normally (24 or 36 exp. rolls), at one point Ilford reduced the weight/thickness of the plastic film base slightly, and was able to pack 72 exposures into a regular 35mm film casette. For the motor-drive users.

https://www.worthpoint.com/worthopedia/72-exposure-roll-ilford-hp5-1884239511

 

Remember that stuff. I never shot any, you'd have to buy a 72-exp developing reel to process it, and find a church belfry to hang it up to dry.