We haven’t done any articles about enlargers specifically, so we’ll kick things off with a very general overview. These monsters might look complicated at first sight, but they’re actually quite simple.

Enlargers are used to produce prints from film (enlargements). They’re essentially a projector — shine light through the film and make a bigger picture. You can then use that picture to expose photo paper and produce a print. Enlargers are also very similar to cameras… except that the light is going the opposite direction (through the film and out the lens).

Here are the basic parts of most simple enlargers. Certainly there are many variations on the design, but they all do the same thing. Sometime soon, I’ll do a video overview of my enlarger, pointing out the parts and showing how to operate them.

photo credit: Whiskeygonebad

Baseboard

The baseboard is usually a thick piece of wood or particle board. It provides a surface for the easel and a mounting point for the support column. The important thing to look for on a good baseboard is the overall flatness of the working surface. If it’s warped, the easel won’t lay flat with the projection and you’ll end up with out of focus prints.

Support Column

Some enlargers have two columns and others have one, but they all do the same thing. The column provides a sturdy frame to hold the enlarger head. It also houses the gear rack for the elevation adjustment. A good support column should be rock solid when assembled and mounted to the board.

Elevation Adjustment

The elevation adjustment attaches to the support column. It allows you to change the size of the projected image. As you move the head further from the baseboard, the projected image gets larger. Most are geared with a hand crank or knob to raise and lower the head (some are motorized) — others are a post and clamp style. Like the support column, the elevation adjustment mechanism will ideally be rock solid to provide stability for the enlarger head.

photo credit: Nesster

Focus Adjustment

Another knob on the enlarger controls the focus by raising or lowering the lens with respect to the film plane (same as a camera). The area between the lens and film plane is typically enclosed by a bellows to allow for a large range of movement.

Film Holder

Most film holders are metal clam-shells with a hole in the middle. They come in a variety of shapes and hole sizes depending on the enlarger. The design of the film holder allows light to be passed through the film as it is held completely flat. The holder is placed between the bottom of the enlarger head and the top of the bellows.

Lens

Enlarger lenses are simple creatures — no moving elements since the focus and zoom is done with the adjustment knobs discussed above. They do have an aperture diaphragm similar to other camera lenses. This is used to vary the amount of light allowed through the lens in addition to improving sharpness of the image.

Most lenses are screw mount (such as the 39mm Leica Screw Mount) and attach to a small lens board (metal plate) that can be removed from the enlarger. There are also a wide variety of high and low quality lenses out there. I started off with some crap lenses, but I quickly upgraded to the more expensive counterparts. I noticed a big difference between sharpness and contrast after I upgraded.

photo credit: dok1

Enlarger Head

The enlarger head is just a light source (basically a light bulb in a box). This light travels down the head, through the film, out the lens, and onto your paper. There are two main types of enlarger heads — they both produce light, but they do it in different ways.

CONDENSER HEAD

These are common for black and white heads. They use two large condenser lenses to gather the light and project it straight down at the negative. This type of light source will produce higher contrast prints, but they also bring out details on the film such as grain, scratches, and dust.

DIFFUSER HEAD

These are common for color heads. They use a mixing chamber to bounce the light around in the head before it reaches a translucent window. The translucent window provides the diffuse light to be passed through the negative. This type of light source produces lower contrast prints, but they will hide scratches, dust, and grain edges. Prints may also appear slightly less sharp because of the lack of grain definition.

I have a ton of other stuff I could talk about with these things (and I’m sure Tom does too), but we’ll save it for later. As I said, this is a very basic overview/introduction to the subject of optical enlargers.

As we go further into the world of enlargers and printing, what questions do you have about this stuff? Are there any topics that you’d like to see covered?