Tuesday, May 20, 2014

Isolette III Overhaul part 5

Ok, two posts in one day must be some kind of a record (for me). Actually, I should have just waited and added this last part to part 4, but I didn't so here it goes.

The (almost) last step is to re-attach the focusing ring to the outer (front) lens element so that when you turn the ring, the front element turns as well. The trick is to make sure that what the ring reads is actually the distance at which the lens is focused. That process is called collimating the lens. First, you need two cameras; the one you are reassembling (camera A) and another with an accurate infinity focus (camera B). First though, we need something on the film plane of camera A on which to focus camera B. I used a couple of pieces of cello tape and drew an 'X' at (or near) the center. Like this:

Screw the front lens element of camera A all the way in (to the right), but not too tight. Now open the shutter on camera A either with a 'T' setting or with a remote shutter release cable and a 'B' setting. My Isolette doesn't have a 'T' setting, so I am using option 'B'. :) Once the shutter is open, point the cameras at each other. I read online that it doesn't matter how far apart they are from each other, but after a few frustrating minutes, I found that camera B must be farther away than the minimum focusing distance of its lens (duh!). I set camera A on the mantle with a light shining behind it (to light up the 'X'), and put camera B on a tripod at the same height.

Line things up so that you can see the 'X' on the tape through the viewfinder of camera B. Now focus camera B at infinity. The 'X' will probably now be out of focus. Start turning the front lens element of camera A counter-clockwise about a quarter turn at a time. You should see the 'X' getting clearer (in my case I couldn't see the whole 'X', but part of it was good enough to focus on). Keep going until the 'X' is in sharp focus.

That's it!! Now I just put the focusing ring on so that the infinity (sidways 8) lined up with the focusing mark and tightened the three set screws. The front element doesn't turn real easy, but I was extra careful not to nudge it and lose my focus point. Now I have a fully functioning Isolette III! I immediately loaded up a roll of expired Tri-X and started shooting. I read somewhere that the springs on these cameras are so powerful that they can suck the film away from the pressure plate and ruin the focus of a shot. So the workflow for this camera goes:

  1. Unfold
  2. Wind on
  3. Focus with the rangefinder
  4. Transfer the number from the rangefinder to the focusing ring
  5. Cock the shutter
  6. Compose and shoot
  7. Fold

Stay tuned to see some photos from this camera. So far, just using it while I walked my dog this evening, I am really impressed with the ease of focusing and the quietness of the shutter. I think this will be one of my regulars from now on.