The Enlarger
Like pretty much everything else in photography, enlargers come in many shapes, sizes, but usually only in black and grey, although I have used a blue one. The enlarger is basically the opposite of the camera: a light-tight box (of sorts) with the light source inside projecting out through a lens/aperture, focusing on a plane.
The Parts
Support
As stated, there are many configurations for enlargers. The most basic use a single pole or extrusion, mounted to a baseboard, which the enlarger housing rides up and down on. This support needs to be sturdy and non-flexible. Different structural profiles are used to increased the solidity. The main support needs to be securely mounted to the baseboard. More often than not, this is accomplished with some kind of foot, spreading the support out.
Many enlargers use a double-beam support. Either way is fine, as long as it is very rigid. You don’t want the weight of the enlarger head to be able to sway the support.
Foregoing a baseboard, enlargers may be mounted to a table, or to the wall.
Lamp Housing
The main part of the enlarger, or the enlarger head, starts from the top with the lamp housing. This is where the light source is. The source can be either incandescent or fluorescent, and there is (have been? At least I seem to remember…) at least one using fiber optics. The difference in the light source entails a difference in how that light is rearranged to create one solid, wide beam going straight down.
The first type, using an incandescent bulb, is usually referred to as a condenser type. A condenser enlarger uses a series (usually two or three) large lenses inside the lamp housing to spread and then project the light from the bulb. This is because the bulb is essentially a point source of light, and needs to spread and evened, to provide even illumination across the negative.
The fluorescent type is referred to as a cold head, or cold light source, or diffusion enlarger (the reason should be pretty obvious). This type is preferred by many, as it gives a softer, often more even illumination. Instead of condensers, the light is passed through frosted glass, to diffuse it. The diffusion enlarger usually requires a voltage stabilizer, and there are timers which compensate for the longer time to full luminosity of the bulbs.
Filter Holder
There is usually some kind of tray here, although the smaller, low-end enlargers may not have one, for filters. The alternative is to use a holder that is mounted under the lens. There may also be a piece of plate glass here (sometimes it’s in the lamp housing) that serves as a heat shield, protecting the negative from ‘popping’, or warping from the heat of the bulb.
Negative Stage
Here is some kind of slot, usually with some sort of lever to open it, so you can slide a negative carrier in and out. The negative carrier is designed to hold the negative as flat as possible. The carrier is usually also designed to fit in one way, with pins or detents or some kind of registration. Many carriers can rotate horizontally in the slot.
Lens Stage
The lens stage has a movable plate to which the lens is mounted, connected to the negative stage. There will be a crank system to move the lens, allowing you to focus. The lens itself is mounted to a lens-board. These lens-boards have different openings, allowing you to mount different lenses for the enlarger, and to change them fairly easily.
The lens has ƒ-stops just like your camera, and they mean the same thing: bigger number, smaller opening.
Controls
Speaking even in the most general terms, it’s hard to say where a given control may be on a particular enlarger. Let’s look at the sequence of getting ready to print. The first thing is to insert the negative in the negative carrier, emulsion side down (shiny side up). If the frame numbers are correctly oriented, you are looking at the shiny side. Next, open the lens stage and insert the negative carrier, making sure it is seated properly. If you are paying even a little bit of attention, most enlargers will ‘feel’ right when it is in correctly.
Now, open the lens up to its widest aperture, and turn the enlarger on, using the ‘focus’ setting on your timer. This gives you the most illumination, continuously, so you can focus. Move the whole head up or down until the image is about the right size, using the crank or handle. Then find the focus knob, and move it up or down and focus the image. You will probably have to go back and forth between moving the head and refocusing to get where you want.
That is the general idea. Most broad and vague, but like cameras, they all work pretty much the same, with the same controls, but they may not have the same arrangement.
