A stop

An exposure stop is a doubling or halving of the amount of light one is working with during a particular exposure.  It is the amount of light being allowed to enter the camera.


Gently moving developing chemicals to evenly process film or photographic prints.


Aperture is the adjustable lens opening that controls the amount of light allowed into the camera.

Aperture Priority

An automatic camera setting that automatically adjusts the shutter speed based on the aperture setting.


American Standards Association is now a defunct rating system for film speed. The ASA has been replaced by the universal ISO. However, it is still a commonly used term.

Auto Exposure

Aperture and shutter speed are automatically determined and selected by your camera.

Auto Focus

The camera lens has the ability to automatically find a point of focus and deliver a sharp image. Auto focus is activated by aiming at your subject, then pressing the shutter release button halfway down (you will see your subject come into focus).

Automatic Film Winder

The automatic film winder will rewind the film automatically so it can be removed from your camera when it is done.


Shooting more than one frame of a scene in different aperture and shutter speed combinations to ensure correct exposure


a printing technique you may use to darken an area of a print by selectively adding light after the initial exposure time is over.


camera is a light-tight box (camera body) that includes a lens and records an image onto light-sensitive material.

Camera mode

Camera modes are settings that allow a photographer to control the parameters of an exposure, specifically, Shutter Speed, Aperture, and ISO

Command dial

A command dial or camera dial is a dial used on cameras to change the camera's mode.

contact proofer

The device used to make a contact proof or contact sheet. A plain clean, clear piece of glass or Plexiglass also works

continuous light

Continuous light is studio lighting that stays on all the time (as opposed to flash or strobes that emit a bright burst of light when triggered

correct exposure

Correct exposure is the correct combination of settings between aperture, shutter speed, and ISO that produced a perfectly exposed image. An image that does not have blown-out highlights or lost shadow details.

Correct exposure results in a print and a negative that have details in the shadows  and highlights of the image


A room without lights where we process photographic materials.

A room with a light-trapping revolving door or equipped with a heavy curtain to trap light. It is also equipped with safe yellow or red lights to use while printing.

Safelights are used to illuminate darkrooms only when making prints. Never when processing film. (There are exceptions for special types of films like Lith film)

Darkroom timer

is a device into which your enlarger plugs in so that printing exposures can be accurately timed.

Density (film density)

The thickness of the silver buildup on a negative or print. High-density areas are dark and low-density areas are light,

The greater the exposure to light, the greater the accumulation of silver, and the denser (blacker) the result once the film or the paper is developed.

Depth of Field (DoF)

Refers to the distance between the closest and farthest objects that appear acceptably sharp in a photograph.


Chemical that converts silver halide crystals to metallic silver, making the latent image visible

developing tank

Diaphragm is the mechanism in a camera lens that creates a variable aperture. It consists of overlapping blades moving together to create the lens opening.


A darkroom accessory use to hold printing paper flat and in place under the enlarger

Electronic SLR camera

An electronic SLR camera requires batteries and a computer chip to operate and it has an LED screen.


A light sensitive layer on film that contains one or more silver halides and captures an image when exposed to light.


The machine which enables you to project the image onto a flat surface. It enlarges the image to the desired printing size and focuses it on the printing paper.


Exposure refers to the amount of light that enters the camera through the lens and hits the film. Basically, it is the measure of how dark or bright a photograph is.

Exposure Setting

The combination of aperture and shutter speed used to expose film.

Exposure Triangle

f stop is the measurement of the aperture/lens opening


Film is a light-sensitive material (plastic base covered with light sensitive emulsion) that captures light when exposed to it, and leaves a negative or positive image. It is this recorded image which we call a photograph. Film comes in different types, and sizes.

Film Changing Bag

A film changing bag is a bag constructed with doubled dark fabric preventing any light to enter it.

Film Developing Tank

A light-tight (plastic) tank is constructed in such a way that light cannot reach the film. Trapping the light is enabled by a hollow post or tube and the special construction of its cover.

film exposure

Film exposure is the amount of light that passes through the camera lens and reaches your film over a period of time. (Light x time) Exposure determines how light or dark your image is.


Film Loading Reels

Plastic or metal reels allow you to load the film in a way that all surface of the film receives chemistry evenly.

Film plane

The area where the film rests in front of the shutter curtain

Film Speed

The number given to various films to describe how fast the film can capture an image when exposed to light. This number is most commonly referred to as the International Standardization Organization (ISO) for film speed.

film-changing bag

Tinted glass, gelatin, or plastic discs that fit onto a camera lens or under the lens of an enlarger to emphasize, eliminate, or change color, contrast, or density.

filter drawer

Part of the enlarger holding the contrast filters. Usually above the lens and below the light source. It may also be found below the lens.


The chemical used in film and paper processing to remove unexposed silver and make the image safe to view under room lights outside of the darkroom

Focal length

Focal length is the distance from the center of the lens, when focused on infinity, to the film plane or the area where the film rests behind the shutter curtain.


Focus is the process of making the image appear sharp at a certain distance from the camera. You focus by turning the focusing ring on your camera while looking through the viewfinder This can be achieved by either using manual focus or the autofocus system your camera provides.

focusing ring

the ring on the front of the lens barrel

Gelatin silver print

Gelatin silver print is a Black and White photograph. The image is made up of silver metal particles suspended in a gelatin layer. Gelatin silver papers are manufactured by applying an emulsion of light-sensitive silver halide crystals mixed in gelatin to a sheet of paper coated with




Clamps of silver crystals on a negative that appear as tiny black or grey grain particles in a print

grain focuser

A grain focuser is a darkroom printing tool. It magnifies the negative grain structure by 10X to 25X. This magnification allows you to focus on the actual grain structure of the image. A grain focuser provides you with the sharpest focus you can get from a given negative.


Grayscale is a range of shades of gray. The darkest possible shade is black, and the lightest is white.


Highlights are the lightest elements in a photograph and the denser/darker in a negative


image sensors

A sensor that detects and conveys information used to make an image by converting light waves into signals in digital photography


ISO International Standardization Organization is a rating system for film speed or the film’s sensitivity to light. ISO has replaced the term ASA


An image on an exposed film or print that has not yet been made visible. Only after development in chemicals, it becomes visible


The curved part of the film at the beginning of a 35mm roll of film


A camera lens is made up of shaped glass pieces with curved surfaces which gather light from the scene you photograph and allows you to focus that light on the film and form the image.

Light Meter

A light reading device inside your camera or hand held that gives you specific information regarding which shutter speed and aperture setting to use for a consistent, well-exposed photograph.

macro lens

lens specially made to focus close up. as close as a few inches from the subject. Other lenses do not have that ability

Manual Focus

Manual focus is achieved by turning the focusing barrel on the lens until the image appears in focus.

Mechanical SLR camera

A mechanical SLR camera works with springs and gears


A reversed image. In negative, the dark areas of the subject appear light and the light areas appear dark.

The negative is your "original" your "master."  It is the main, official version of the image you made. Any damages compromise irrevocably your photograph


A negative is an image, usually on a strip of transparent plastic film, in which the lightest areas of the photographed subject appear darkest and the darkest areas appear lightest, in other words, it is the exact opposite of the print.

negative carrier

Component of the enlarger. It holds the film by its edges and keeps it flat and parallel to the lens plane. A negative carrier is necessary for the correct projection of the enlarged image onto the enlarger base

negative carrier tray

Part of the enlarger above the lens where the negative carrier is inserted.

Negative film

NEGATIVE FILM: Captures images as a “negative”, in which colors and values are inverted.

overexposed negative

Dense, dark negative. An overexposed negative has low contrast, overall high density, is too dark in the shadows, and too dense in the highlights


Photograph or print is an image formed on paper by photographic means.

prime lenses

Prime lens is a fixed-focal-length lens. It could be wide, normal or telephoto


A type of camera with a focusing system using two superimposed images, split image. The image is out of focus when the images are separated and in focus when they come together.

reflective light meter

A reflective light meter reads light that bounces off the subject

Resin coated or RC printing paper

Printing paper coated with clear plastic (resin coated). It comes in different sizes and finishes

Reversal color film

REVERSAL FILM: Also known as “slide film” when it refers to 35mm, captures images as a “positive”, replicating color and values directly.

rewind button

The button you press to release the film from the take-up spool and rewind it back to the canister

Rewind knob

Mechanism used to rewind the film back into the canister.

rewinding button

A small button usually at the bottom of the camera. When pressed it releases the film from the take-up spool and allows for rewinding the film back to the canister


By definition, the safelight is a light source emitting light in an area of the spectrum that does not affect the light-sensitive materials for which it is designed. A safelight is essential in any darkroom


Shadows are the darker areas in a photograph and the lightest/thinnest in a negative


Shutter or shutter curtain is a shield in the camera protecting the film from light. It is right behind the film plane.

shutter curtain

Shutter or shutter curtain is a shield in the camera protecting the film from light. It is right behind the film plane.


shutter release button

The button you press to take a picture. When you press it the shutter stays open for the time the shutter speed is set.

shutter speed

The length of time the shutter(curtain) stays open during exposure. The photographer sets the desired time using the shutter speed dial

silver halide crystals

Silver halide crystals are light-sensitive chemicals.  They are mixed in the film emulsion to make photographic film and paper react to light

SLR Camera

SLR stands for Single Lens Reflex. The camera has only one lens (single) which forms the image to be recorded on the film and is shown through the view finder.

stock solution

A concentrated solution (as of developer or fixer) that usually is diluted with water before use in photography.

stop bath

A weak solution of acetic acid. it neutralizes (stops the action) of the developer for film and prints

test strip

A section of printing paper with several different exposures from a single negative used to determine correct printing exposure

Through the lens metering/TTL

Through The Lens metering/ TTL. When you focus your camera with that half push of the shutter, your camera is not only focusing, but it's taking a reading (metering) of the scene. That measurement tells you how much ambient light is reaching through the lens the film


Through The Lens (TTL) metering.

underexposed negative

Thin, light negative. An underexposed negative has very low contrast, overall low density, lacks detail in the shadow, and weak highlights.

underexposed photograph

A photograph or print appearing darker than the actual scene. Lacks shadow details and highlights are grey

Wetting agent

A chemical solution used after washing the film. By reducing the surface tension of the water remaining on the film, it speeds up drying and prevents water spots.

word or phrase underlined red

Here is where you'd see a definition.

working solution

Chemical solution that has been diluted and is ready to use


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Photography: What, How, Why Copyright © 2023 by Maria Politarhos and Randy Matusow is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

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