Locking focus ring

[ZiHao]

In manual focus, the focus ring might shift a bit when I am shooting widefield images and taking flat frames, is there a way to lock the focus ring? Thanks.

[Chefgage]

This drives me a bit mad when using my 75mm to300mm lens. You only have to look at it and the focus changes. I have read about using a wide rubber band over the focusing ring so it makes it more difficult to move, so that should help. Also using a bit of blu tack (but I would have thought as you apply the blu tack you run the risk of altering the focus). The rubber band idea seemed best to me but I have yet to try it.

[TerryMcK]

+1 Blutack

[michael8554]

Gaffer tape

Michael