what is the use of an infinity lock?

-- stefan randlkofer (geesbert@yahoo.com), December 12, 2001

Answers

....ummmm...to lock the lens on infinity????

-- Steve LeHuray (icommag@toad.net), December 12, 2001.

It's major use is to unnerve photographers. If my old Leica lenses weren't so collectible, I'd file down the lock thingy. I was very happy when I replaced my chrome 21/3.4 S/A with the later black one: no more infinity lock.

-- Jay (infinitydt@aol.com), December 12, 2001.

The older lenses didn't have anything to hold on to to unscrew the lens unless you cranked it all the way to the closest distance before removing it, and then back to infinity before screwing it back on. An infinity lock theoretically adds a little more meat to hold onto while mounting the lens, without as much spinning to get it to a point where you can exert leverage. Earlier M lenses such as the 28mm and 21mm had NOTHING to hold onto except the infinity lock, unless you wanted to grab the front and risk stressing and twisting the hood out of alignment.

-- Michael Darnton (mdarnton@hotmail.com), December 12, 2001.

1.the locks make the collapsible lenses hold still while you extend and twist them into place or untwist and telescope them and 2.they make the lenses similarly hold still while you mount or unmount them from the camera. The infinity locks are highly annoying until you have them disabled and you suddenly find out what they were there for.

-- david kelly (dmkedit@aol.com), December 12, 2001.

I figured out what they were for on my 3.5 Elmar, but I still disliked the lock and disabled it anyway. What I hate is when you are focusing on something maybe 15 or 20 feet away, and than the lock come around and messes you up.

Now why was there a lock on my 35mm f2.8 Summaron M mount lens? That one makes less sense to me than the one on the screw mount Elmar, and it is also a lot harder to disable. I'm living with it for now but would prefer it wasn't there. My vote for the worst infinty lock is the one on the body focus wheel of the vintage Contax RF cameras.

-- Andrew Schank (aschank@flash.net), December 13, 2001.

Andrew,

And that of the Nikon which copied it...never got the hang of using either of them.

-- Dave Doyle (soilsouth@home.com), December 13, 2001.

Obviously to lock the lens at infinity. But what a nuisence they are, especially when focusing at near(20ft +),but not absolute infinity, and the darned thing locks into place. I have disabled them on all my screw mount lenses.A small piece of Dymo tape,cut to size and placed in position on the shank does the job.A friend of mine winds cotton around the shank to keep it in a raised position and that also works fine

-- David Seaman (Lincolnshire,England) (david@leicam.freeserve.co.uk), December 13, 2001.

Hi, Like David, I hold up the locking pin,wind a few threads of cotton around the pin base and release it. It just stops the infinity lock from engaging.

-- Julia (julia@lorena.fsnet.co.uk), December 13, 2001.

Thatīs a good solution Julia, for so long Iīve tried to fix it with pieces of wood rr plastic, but your idea seems logical, thankīs Iīll try it soon.

-- r watson (al1231234@hotmail.com), December 13, 2001.

About 8 yrs ago I sent my pretty old SUMMICRON 50 mm lens (1957, with IL) to Solms to have it CLAed. It came back with the rigid bit of the IL filed down. I hadnīt asked for it and I still donīt know if I decide this was a good idea or not. The lens couples and uncouples easier with the lock, but for focussing it is a nuisance.

So I keep wondering.

Best wishes

-- K. G. Wolf (k.g.wolf@web.de), December 14, 2001.

Before you guys go out there and file down your lens, look first! Why? On my 50mm rigid summicron you can unscrew the little push tab from the bottom. This means you can disable the infinity lock without filing down the tab!

-- Russell Brooks (russell@ebrooks.org), December 14, 2001.

Hello Russell,

should have explained this with some more detail:

they did not file the thing down completely, just (a guess) 20% of the rigid part which looks like a mushroom. It is still there and catches the thingy on the focusbarrel only slightly now.

Best wishes

-- K. G. Wolf (k.g.wolf@web.de), December 14, 2001.

I ben usin it for fity yrs an I lik it.

-- Williuhn (bmitch@home.com), December 14, 2001.

so some people really seem to like the infinity lock. but there are also people who like focussing tabs. i don't. can't get used to it.

-- stefan randlkofer (geesbert@yahoo.com), December 15, 2001.