Summer is arriving tomorrow, so what better way to start things off than to present you a small contraption I call the Dim-Larger. It's a small rainy day project that requires a bit of electrical knowledge... if you can install a dimmer switch in your home, you can build this one!
It all started with a small problem I had in the darkroom. My enlarger is too bright! Some would say this is a big plus, but in reality it is not. Has anyone tried to dodge and burn a print in 4 seconds flat? Then you get my point. I could close down the lens to increase the times, but it also brings in additional depth of field which extends all the way to the condensers... and every dust speck on it. So it isn't really an option.
I could use neutral density filters... that would work but it's also a bit of a pain to use.
While reading an old darkroom book, I stumbled upon something quite interesting: all professional printers at a local newspapers used to have a dimmer hooked up to their enlarger. This enabled them to use a constant exposure time and vary the exposure by changing the intensity of the light. It also allowed them to exercise their eyes to match each negative. They would process
all their prints in batch before leaving and rarely screw-up more than one or two prints a day... Now that is interesting!
So, I set out to build one. I found an old dimmer taped to an old lamp on the side of the road (please don't ask... it was electrocution waiting to happen). I picked it up and went to the electronics store to get a small project box to fit it in. I chose a plastic one so it would be safer to use. I also used a small power bar I got at the dollar store for 2$. It was small and flimsy but had a grounding wire... perfect.
So, I cut the wire in about half and stripped the wires. Drilled two holes on the side of the project box to fit the wires in. To easily locate the dimmer in the box, I removed the button, applied a bit of silver paint to the protruding post and put it in the box. It left a mark where it's supposed to go making drilling this one easy. All that was left was to connect the wires. I used solder but really should have used either wire nuts or crimp-on connectors (they're easier to use).
As a rule of thumb if you live in North America, the white cold wires get connected together. The green ground wires also get connected together. The black wires are the dangerous hot ones. These are connected on one side to one of the dimmer's black wires, same thing on the other side. I don't know if the same standard is used throughout the world, so check with somebody who knows their electricity (the hardware store is a good place to start).
Once everything was connected, I did a check to make sure it was safe and connected it to the enlarger for a trial run. I also went through the trouble of using an exposure meter to roughly calibrate the device in 1 f/stop increments and made a nifty sticker to put on the top of it
Now, all that's left to do is use it in the real world.
Here's a picture for inspiration
Enjoy!
