What is best lubricant for sliding metal on metal parts?

[nic_olas]

What is best to apply to sliding metal on metal points?

I have an older Konica (Autorex/Autoreflex) that sets the lens aperture by quickly turning a stop down ring, linked to levers and the shutter button. It tends to stick or lag, unless the screws are really loose and it can move more freely. It's basically two rings on top of each other, one turns quickly at a button press and needs to be snappy to work apertures in time.

It's all mechanical, 60s era akin to trap needle metering systems, but with a whole mechanism to stop down the lens in step with shutter actuating.

Half my roll was underexposed because of this being laggy I think.

Thanks!

[kmac]

Hi, The camera needs cleaning to remove old gunk and pollution, and then lubricating by rubbing an oil soaked tooth pick over the various parts. 

[John Farrell]

The problem with oil is that it will migrate into the diaphragm blades. These should be dry - oil will stick them. Diaphragm rings can be lightly greased - but over time the oil component of the grease can migrate onto the blades...

[conrad_hoffman]

Oil and grease will only slow it down, plus the migration problem. It's either gunked up or something's slightly bent. Perfectly clean and dry it should move as fast as it's capable of moving. If distant from shutter/aperture blades, I'd use a trace of Superlube oil to keep wear down. 

[JDMvW]

Graphite in a suspension works well

[gary green]

I mentioned this in a similar thread.  I have been extremely satisfied with 3-In-One Dry Lube for lubricating metal sliding parts.  It goes on wet but dries very quickly.  I typically wet a cotton swab and dab it on.  It will wick into joints so use sparingly to avoid it spreading too far.