[MF3D.FORUM:1076] Sputnik focus adjustment

[Brenda Nowlan <bknowlan@xxxxxxxxx>]

Hi Harolddd,
Here are the directions I got to adjust the focus of the lenses from
Elliott S. and Tom D.  It worked for mine.
> Here's how to adjust it without a big buck collimator...  Take a piece of
> clear acrylic (good quality-- 1/8 inch or so) and scratch a bunch of fine
> lines across it. Tape it to the back of the film plane so it's absolutely
> flush. Set the camera at infinity focus and the aperture wide open. Set
> the shutter at B. Connect a locking cable release. Press the cable release
> until the Spud shutter opens, and lock it there. Have the camera aimed at
> a reflective source-- a sheet of white paper with a light on it is fine.
> Take your slr and set *it* at infinity focus-- mox nix what kind of lens
> is on the slr.  Aim the SLR at the lens opening (front of the Sputnik). 
> Rotate the front lens element (the one that screws), all the time looking
> through the SLR finder, until the scribe lines are razor sharp. When they
> are, the Spud is set at infinity focus, or close enough for government
> work. Re attach the front ring. Do the same with the other side. 
>
> I removed the heavy grease on the front lens and replaced it with Radio
> Shack Teflon gel (won't migrate, won't attract dust, won't get hard and
> gummy).
>
> The above is based on the principle that parallel lines converge at
> infinity. Einstein was right!
Mike Cantor added this:
> One small comment, though: the descibed procedure for using your SLR as a 
> collimator will work most acurately if the focal length of the lens on the 
> SLR is equal to (or even better, longer than) the focal length of the lens 
> you are adjusting.
Hope this helps you.
Brenda