Infinity Focusing

[Skyliner]

Having dismantled a lens to remove the usual lint, small insects etc How do I reset infinity focus precisely?
My nagging doubt is that I may be getting it slightly out and compensating with the diopter. (I am not convinced that sharpening the f/numbers graphic in the viewfinder is the right place to bootstrap all the settings from, It should be the film plane, but how?

[eidde]

hello
I dont know which camera you are using, or anything about the lens, but Ive done this, and basically I did the following.

I took the lens completely to peices.

When reassembling it I had two major peices that slotted into each other. One of these (the focus ring) had the distances labelled on it.

I could see that turning this section all the way in one direction was the infinity setting.

I slid the peices together and then made sure that this peice was firmly turned in that direction and wouldnt go any further before putting the tightening screws.

That worked a treat. The focus ring turns fully one direction matching the infinity with the little line on the other section. Turn it the other way as far as it will go and the smallest distance (I think its 1 metre) matches up with the line.

hope that helps

[Skyliner]

Thanks Eddie
This is a fujica Z2 (single-8) which I like to use because of the backwinding, variable shutter and lack of jitter
The stop ring you are talking about is held on to the front lens by 3 little grub screws. When you undo them the factory setting is lost. I may have been able to just remove the stop screw and clean the rear of the front lens in it's mounting ring but thats 20/20 hindsight for you [img]redface.gif[/img]

[Skyliner]

I think this
http://www.pauck.de/archive/mailingl.../msg02027.html
Is the kind of process I'm looking for (if I can get my head around it [img]graemlins/wonder.gif[/img] )