Hi, I am looking for some advice on how to remove a stubborn lens retaining ring.
I have a Copal 0 shutter mounted to a recessed Linhof board which I need to remove in order to fix the cable release elbow. I have removed both lens elements and opened up / retracted the aperture blades. Using a spanner wrench I have tried to undo (anti-clockwise) the retaining ring but it's not budging. This is the first time I have attempted this, so am unsure of how much pressure to apply. I read of someone putting the spanner wrench in a vice to gain more leverage, but I'd like to clarify that first before having a go. Any advice gratefully accepted, Rob.

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