Tuesday, April 8, 2014

Isolette III Overhaul part 1

I have never done my own CLA (Clean, Lube and Adjust) on a camera before, but I just recently got a wonderful Agfa Isolette III that has some problems. The Isolette III is a medium format folding camera with an uncoupled range finder. That means that when you look through it, you look through a range finder (not through the lens) that gives you a distance to your subject. You then transfer that distance reading to the focusing ring of the lens. A coupled range finder would have gears and levers that would move the focus mechanism on the lens for you when you adjusted the range finder. I like old mechanical, "figure it out yourself" kinds of cameras, so this one is perfect. It has good glass (an Apotar which is a good Cooke triplet) and the build quality is what you would expect from a mid-century German made camera (excellent). Now I mentioned that there are problems, and there are.
  • There is a light leak in the bellows, so the bellows will need to be replaced.
  • The wheel that turns to adjust the range finder is very stiff, probably from coagulated grease.
  • The focusing ring is completely frozen, probably from the same grease.
  • The shutter works, but the blades move very slowly.
This may seem a bit daunting at first, but there were so many of these cameras made and made well, that they are still around today in very good numbers. The problems I listed above are pretty common too, so there is a good amount of documentation on how to go about fixing these and bringing them back to their former glory, or maybe even making them better!

Instead of jumping right into the lens/shutter assembly, I thought I would start with the "easy" part of getting the top cover off and seeing if I couldn't get the range finder wheel to move a little more smoothly. Unfortunately, I couldn't find any documentation about removing the top cover on this model. But how hard could it be? There are a few screws. Take those out and the cover should lift right off, right??? Well, sort of. The two tiny screws that hold the distance/aperture reference ring on the left side are pretty straight forward and there is a larger screw under that. There is a tiny screw on the right end that has to come out as well. Then there is the film winding knob. There is a large screw in the middle of that. The slot in it is super thin and I didn't have a screwdriver with a narrow enough blade to unscrew it. I have some small screwdrivers, but they didn't provide enough leverage to loosen it. This thing was TIGHT! I went to the hardware store hoping to find something narrow and wide that would provide the leverage to get this thing out. No luck. So I tried the dull edge of a razor blade held in a pair of needle nose pliers. This fit the slot just fine, but after breaking every one, that screw had still not budged. So I thought I would use my rotary tool with a cut-off wheel to widen the slot on the screw just enough to get a regular screw driver in there and really apply some torque. So that's what I did. It didn't take much and I was able to get a regular screwdriver blade in there and really put some muscle to it. Still it wouldn't turn, not even a millimeter! I sat back and started contemplating how I was going to have to drill out the screw and find a replacement. I stared at that takeup spool knob with its little counter-clockwise arrow mocking me. Wait... the arrow... You turn the knob counter-clockwise to wind on the film. I wondered if maybe the screw turned the other way in order to keep it tight over time. Well anything was worth a try at this point. So I slotted the screwdriver blade and made a clockwise turn. BAM!!! It turned!!! Unbelievable. I had to give a little growl of protest to the ingenuity of the German engineer who came up with this brilliant idea that keeps the winding knob from getting loose. Klaus, wherever you are... Thank you, and I hate you.

So now the top was off. There is usually another internal cover over the optics of most range finder cameras. It helps to keep the dust out. This was no different. There were four screws visible and I started taking them out, not paying any attention to the piece of old cello tape that fell off of one of them. But when I got to that one, I noticed that it felt different. It wasn't coming out. I turned it back the same number of turns I had turned it out. It was not holding the cover on. It was an adjustment screw. It is in the center of the cover at the edge toward the back of the camera. The rest of the screws came out fine and the cover came off revealing the simple optics that make up the rangefinder. The glass needs some gentle cleaning, but I will be careful not to touch the half-mirror. It is coated and if you remove any of the coating, you will ruin the whole thing. I still need to get the thumb wheel off, clean off the grease and add a tiny bit of lithium grease, but that should be pretty straightforward. The only hitch will be getting the wheel off. It has a pin-screw head. That means instead of slots, it has tiny holes that require a special tool to loosen. Mine is on the way, so I should be getting that going very soon. Here is a photo of the camera with the top cover and the internal dust cover removed.

Stay tuned for more Isolette fun!