Flange vs. Retaining ring

[Thom Bennett]

I received a lens (Fuji 420mm L) that came with a flange rather than a retaining ring. I've been searching for a Copal 3 retaining ring but I'm now thinking that I will just use the flange. So what are the benefits/detriments to using a flange rather than a retaining ring?

Thanks,

Thom

[cdholden]

I once bought a second flange for my 14" Ektar, so I could unscrew the shutter quickly to use between two different cameras. This would be a huge pain in the ass with an unsecured retaining ring.
If you want to mount it to a single lens board like most normal people (which I eventually did), either one will do the job. With a flange, you also don't have a worry about it coming unscrewed. The flange is secured to the board by screws, rivets, chewing gum and duct tape, etc. Retaining rings screw on, but some also have holes for screws to secure it to the back of the board. YMMV.