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Adapter Ring. This device is used to adapt filters to fit your lens. Adapter rings come in various sizes and are an excellent way to use filters that are to large or small to fit the filter mount of a lens. Also an excellent way to allow one filter to be used on several lenses. This is much cheaper than purchasing filters for every lens you own.

Angle of View. The angle of coverage for a lens of a given focal length. This is determined by the angle made on the diagonal of the film plane.

Aperture. See: F-Stop.

Aperture Ring. The knurled ring used to adjust the f- stop of a lens. See: Click Stops.

Artificial Light. Light other than that produced in nature. Or, you could say man-made light. Light produced by incandescence, electronic flash, candles, gas and kerosene lamps.

Automatic Focusing Capability. The ability of a camera - lens system to focus the lens without human intervention. This is available on still cameras, digital cameras, and camcorders.

ASA. American Standards Association. No longer used, but will be found on older equipment. See: ISO and DIN.

Available Light. Existing light without any additional light being added to make the photograph. Available light can be artificial light.

Averaging Meter. A light meter that measures the light from a broad area and averages the scene into one exposure value.

Background. Area behind the subject.

Background density. The density of any element of portion of a negative or print on which there is no image or density. See: Fog level.

Back Light. Light that falls on the subject from behind. This light can be used for silhouette or a halo effect.

Barn Doors. This device can be used to vary the light out put from a light of an electronic flash head. Usually there are four, top, bottom, left, and right, flaps. They resemble barn doors and so have been named. They clip on your light. Be careful! When used on incandescent lights they get hot. and their added weight will require a secure clamping rig for the light.

Base. The supporting medium for photographic emulsions.

Bellows. A device used for macrophotography. It allows you to vary the distance between the film plane and the lens so that the subject can be brought close to the lens. The bellows is attached to the camera body and the lens is attached to the other end of the bellows. You then move the lens back and forth until the subject is focused. Also a light tight, folding sleeve between the lens and the film plane on large format cameras and other cameras that have tilts and swings. See: Extension Tubes, and Reversing Ring.

Between the Lens Shutter. This shutter is located between the lens elements literally inside the lens usually near the diaphragm. When you remove the lens you also remove the shutter.

Bleed. A unsavory way to refer to a picture with no borders. The image extends to the edge of the paper.

Bounce Flash. Here light from the flash is aimed at a wall or ceiling to bounce, i.e. reflect onto the subject.

Bracketing. This is the taking of the same photo at several different exposures. For example you might shoot at a shutter speed of 1/500 @ f8, f16, f5.6 when the indicated exposure is f8. This gives you one stop over exposure and one stop underexposure. Or you can vary the shutter speed.

Brightness Range. This term describes the the difference in illumination between the darkest and lightest areas of the subject. It is important because you want the film to have the latitude necessary to capture this range, otherwise, you get bright or dark areas that are outside the film's ability to record detail in those areas.

Brilliance. The intensity of light reflected from any surface. It is sometimes an alternative term for luminosity.

Bulb. This shutter speed setting will keep the shutter open as long as you hold down the release button. It can be used for time exposures, or exposures that will be longer than the cameras longest shutter speed. See: Time Exposure.

Bulk Film. Film purchased in bulk. That is in rolls of fifty or one-hundred feet and loaded one role at a time by the use of a bulk film loader and your own reload-able cassettes. Also used in cameras that have bulk film backs.

Burning. The selective added exposure to a particular area of a photographic print. See: Dodging.

Cable Release. This flexible device attaches to your shutter release button. Generally used with the camera on a tripod to minimize vibration or to lock the shutter open for long exposures.

Cadmium Sulfide Cell. CdS this light sensitive cell is used in exposure meters. The CdS cell requires an electric battery for function. The electrical resistance of the cell is dependent on the amount of light it receives. As the resistance changes the cell's out put changes and supplies you with an electronic signal corresponding to the amount of light.

Camera Movements. This refers to the ability of large format, and others, to move the film plane and lens plane relative to each other. Also called tilt and swing as these movements occur in length, with and height.

Color Temperature The color temperature expressed in degreed Kelvin is the temperature to which a perfect black body radiator would have to be heated to emit light of the came color as the light source in question. A perfect black body will emit light only it will not reflect any light falling on it.
color temperature is applicable to all solid incandescent light sources. For electronic flash and other discharge lamps the color temperature is an estimate as these devices do not have a continuous spectrum. See: Mired.

Color Correction of CC Filters Color Temperature Correction Filter. CC filters are designed to correct film for the light source being used to expose the film. See: Color Temperature Meter.

Color Temperature Meter This instrument will measure the color temperature of a light source. See: Color Temperature Correction Filter.

Centigrade Temperature Scale. This is the metric temperature is a scale. The freezing point of water  0o and the the boiling point to 100 C.

Changing Bag. A usually black light tight, double zippered, cloth bag used for changing film or loading large format film holders.

Characteristic Curve. This graphically illustrates the performance of a film. The graph shows the relationship between the film's exposure to light and its developed density under known developing conditions. The curve gives you information on factors such as emulsion speed, fog level, and the film's contrast. The slope of the curve of the characteristic line is called Gamma. This is also the tangent of the line at any point.

Click Stops. A position on a f-stop indicator that gives you an audible and tactile click. See: Aperture Ring

Clip Test. is a short sample of film, cut from the main exposed roll, used to determine the appropriate development and/or fixing time.

Close-up Photography. See: macrophotography.

Close-up Attachment. Any accessory that allows the lens to focus closer than the minimum distance it is designed for.

CMYK. Abbreviation for cyan, magenta, yellow and black. These are the colors used in the four color printing process.

Cold Colors. This does not relate to temperature but to the perception of color by humans. These colors are at the blue end of the color spectrum and suggest a cool atmosphere.

Color Balance. An adjustment in the color photographic processes ensuring accurate reproduction of a neutral gray scale.

Color Balancing filters. These filters are designed to balance color film for the color temperature of the light source in use. This allows for proper color rendition.

Color Shift. Variation from normal color rendition. Caused by film stored in hot location, outdated film, or pushed film. Also occurs when film is exposed to light that the film is not designed to be used with. For example: the red shift that occurs with daylight film exposed to incandescent lights. Fluorescent lighting makes your results green with daylight film. These problems can, of course, be corrected with filters or proper film choice.

Color Wheel. A chart of the colors of the visible spectrum presented as a circle.

Contact Print. This print is the size of your negative. It is made by placing the negative in contact with the photographic paper and exposing it to light. In 35mm photography a contact sheet can be produces that contains images of an entire roll of film.

Contact Printer. A device used for making contact prints.

Contrast. The difference in density, or luminosity, and the degree of tonal separation in a subject, negative or positive print. See: High Key Photograph, Low Contrast Light, and High Contrast Photograph.

Cut Film. This refers to film that is supplied in sheets such as that used in large format cameras.

Crop or Cropping This is enlarging a section of a photograph. This is routinely done to improve composition or to leave out parts of a photo that are important or distracting.

Depth of Field. The zone of focus which is rendered acceptably sharp.

Depth of Field Scale. Indicates the depth of field at any distance and aperture. Found on camera lens barrel.

Depth of Focus. This the distance that the film plane can be moved while maintaining an acceptably sharp image without the need to refocus the lens. This is important when using cameras that have a movable film plane.

Diaphragm. is a term used to describe the adjustable aperture of a lens. It controls the amount of light passing into the camera and may be in front of, within or behind the lens.

Diaphragm Shutter. is a between the lens camera shutter that performs the function of the iris diaphragm.

Differential Focusing. The use of your depth of field to produce minimum depth of field, so that image sharpness is limited to a particular subject element.

Diffuser. Any material placed over a light source or the lens can scatter or diffuse light. The effect of a diffuser on the camera is to soften an image. On your light source it will make the light softer and less prone to create shadows.

DIN Deutsche Industrie Norm (German Standards Organization). Similar to our ISO. Older cameras can be found with an ASA-DIN converter so that European films rated in DIN could be used. See: ISO, and ASA.

Diopter This expressed the magnifying power of a lens. It is the reciprocal of the focal length expressed in meters.

Discharge Lamp. A gas filled tube that gives off light when an electric charge is passed through it. One can be found in your electronic flash.

Dodging. In the printing of photographs this is used to control exposure to certain areas of the print by holding back light. See: Burning.

Double Extension. This relates to large format cameras where the bellows can be extended to twice the focal length of the lens in use allowing the camera to be used for close up or macrophotography.

Drying Cabinet. A vented cabinet for drying film.

Drying Marks. Marks in the film emulsion from uneven drying. These marks may cause areas of uneven density, which may show up in the final print.

Dry Mounting. A method of mounting, or attaching, is a method of attaching photographic prints to a cardboard backing to aid in displaying or framing pictures.

Dyad Any pair of complementary colors or any two colors considered visually harmonious. See: Color wheel.

Double Exposure. Two exposures made on the same piece of film or paper.

Electronic Flash. This piece of equipment produces light by firing an electric current through a gas filled tube. The tube then yields light. Generally operated by batteries, they have virtually replaced flash bulbs.

Emulsion.The chemicals that respond to light on photographic film or paper. See: Film.

Exposure. The brightness of light and the time it acts on the film. Controlled by the shutter speed and the lens aperture. See: Push and Pull.

Extension Tubes. These devices are use for macrophotography. They allow your lens to focus to a closer distance than it normally would.

The extension tubes mound between the camera body and your lens. They come with several different lengths which can be all screwed together and are of varying length. In this way you can make up several different lengths. They are less expensive than a bellows. See: Bellows and Reversing Ring.

F-Stop. Think of a Venetian blind, like the ones you see in homes and stores. The aperture or f-stop does the same thing in the camera that the blinds do in your home, it controls how bright, or intense, the light will be when reaching the film. Just as a set of blinds admit more light when open one forth inch than when open one sixteenth inch, so does your camera admit more light at f4 than f16.

Filter. A material that changes the color, quality, or brightness of light.

Film. The base to which the light sensitive emulsion is attached. Loosely refers to the material that the photo is recorded on.

Film Speed. Refers to the film ISO. Films with high ISO numbers are said to be "fast" those with low ISO numbers are said to be "slow."

Fisheye Lens. A very short focal length lens with a field of view of about 180 degrees. Be careful using this type of lens you can easily get your toes in the shot! Yes, your toes these lenses truly provide a 180 degree field of view. This lens may require you to lock up your shutter because they actually extend into the camera body so far that your mirror has no room to travel up normally. Be sure your camera has a mirror lock up button.

Focal Length A good definition for our needs, while not technically precise, is that Focal Length is the distance from the optical center of the lens to the film plane, CCD, or CMOS of a digital camera.

    The precise optical definition is: The distance from the plane in which the lens forms an image at infinity to the node of emission.
The focal length is usually on the lens and appears as: f=100mm. This is a focal length, f, of 100 millimeters.

Fog level. The density formed in unexposed areas of film or paper during processing. See: Background density.

Foreground. The area in front of the subject in a photograph.

Gamma, of Characteristic Curve. The slope of the curve of the characteristic line is called Gamma. This is also the tangent of the line at any point. See: Characteristic Curve.

Grain. The sandy or mottled appearance of a picture or negative. This is a result of tiny clumps of silver crystals that form the photographic image during film development. The faster the film the more visible the grain, however even fast films are now fine-grained.

High Contrast Photograph. A picture made to contain deep shadow and light tones. Or lighting that creates deep shadow and light areas. See: Contrast, High Key Photograph, and Low Contrast Light.

High Key Photograph. A picture made up almost entirely of light tones. See: Contrast, Low Contrast Light. and High Contrast Photograph.

Hot Shoe. A type of flash attachment that does not require a cable to the camera. The necessary connections take place at the point where the flash and camera mount together. See: PC-cord.

Hyperfocal Focusing. This technique uses depth of field to obtain a zone of acceptable sharpness. For example: with a 28mm lens set at f16, place the infinity mark on the lens barrel at the f16 mark on the depth of field scale. You will find the other f16 indicator at two or three feet. In this way you get sharp photos of everything from three feet to infinity.

Kicker. Reflector used flash or other lighting for filling shadows or dark areas. Can be white paper or cardboard attached to a flash, or a separate flash unit.

Lens Barrel. The metal or plastic tube which contains the lens elements.

ISO. International Standards Organization. This term refers to a films sensitivity to light, the greater the number the more sensitive the film. It can also be used to refer to standardized connections and devices. See: ASA and DIN.

Low Contrast Light. Light that creates little or no shadow. See: Contrast, High Key Photograph, and High Contrast Photograph.

Luminosity. The brightness of a source of light or a reflective surface.

Luminous flux. The intensity of a light source, measured in lumens.

Macrophotography. Technique of taking larger than life photographs with an ordinary camera lens. The image in the camera will be the same size as the subject, or larger than the subject. If you are shooting a one-half inch worm you will have an image of the worm that is one-half inch long measured on on the slide or negative. That is what is meant by a scale of 1:1, one to one, the size of the image is equal to the size of the subject. See: Photomicrography.

Meter - metric A unit of length in the Metric system. One meter is equal to 39.37 inches. A millimeter is one-thousandth of a meter. There are 25.4 millimeters in one inch. You may also see metric length in centimeters. There are 100 centimeters in a meter and 2.54 centimeters in one inch.

Mired Contraction of "micro-reciprocal degrees." The mired value of a light source is the color temperature in degrees Kelvin, oK, divided into 1,000,000 (one-million).
For example: A light source of 5000oK corresponds to 1,000,000/5,000 = 200 mireds.
3200oK  to about 313 mireds. See: Color Temperature.

Mirror Lock Up Button. This will keep the camera's mirror in the up position. It is needed for fisheye lenses.

Modeling. The affect of light on the subject to show texture.

Monopod. A one legged camera support with extension capability. Excellent for ease of movement with along lens.

Motor Drive. A battery operated device that advances and rewinds the film in your camera. Motor drives typically can operate at 5, or more, frames per second.

Motor Winder. Similar to a motor drive. A winder will advance the film, but not rewind it.

Over Exposure. When the film has been exposed for too long to light, this is caused by a shutter speed that is too long. Or, to an aperture setting that is too large. Or, of course, to a combination of the two. Over exposed photos are too light. You could say that they look like a white cat drinking milk in a snow storm. See Under Exposure and our black cat analogy.

PC-Cord. The cable that connects a electronic flash to a camera. By means of this cord does the camera signal the flash to fire at the proper instant. Named for its french inventors. See: Hot Shoe.

Photomicrography Photography of about 10X or greater. This is usually done through a microscope. See: Macrophotography.

Preflash. When a very limited exposure is used before the main exposure to record the image. This technique is used on film and paper to reduce contrast and/or grain.

Pull Film. This refers to exposing film at an ISO which is lower than what the film is rated for. The processing must compensate for this.

Push Film. this refers to exposing film at an ISO which is greater than what the film is rated for. The processing must compensate for this.

Reciprocity Failure. A loss of film speed occurs when film is exposed for very short (one ten thousandth second or less) or very long exposures (hours). This is not usually a problem under normal circumstances. This can be a problem in astronomical photography where very long exposures are routine. Time Exposure

Reversing Ring. This attaches to your lens in a way that is similar to a filter. It allows you to attach the lens backwards, I.E. to turn the lens around. This gives a closer film to subject distance, allowing closer working distances. Least expensive of all close-up equipment. I keep one permanently attached to my 50mm lens. Great when your traveling because it is very light weight. See: Bellows, and Extension Tubes.

Shutter. The device that controls the length of time, measured in seconds, that the film will be exposed to light. Note: the term shutter speed does not refer to how fast the shutter is traveling, but to the length of time that the shutter is open.

Single Lens Reflex. This refers to cameras that take the photograph and allow you to view the subject through the same lens. This is possible by the use of a prism and a mirror. The mirror is located behind the lens and reflects the image up into the prism. It is the prism that corrects the image back to your eye so that the image is right side up. This combination provides an erect image, that is, the image reaching your eye looks the same as the scene as viewed without looking through the camera. What is on your left, is on the left side of the image, what is in your right, is on the right side of the image.

Telephoto Lens. A lens that makes the subject appear closer that it actually is.

Time Setting and Time Exposure. Time exposure setting on shutter speed dial. This will keep the shutter open until you physically move the shutter speed dial off of this setting. Used for long exposures. This feature can be duplicated with a locking cable release and the use of the bulb setting on your shutter. Time exposures are long in duration and are used extensively in Astronomy and other situations where very low light levels exist. Any exposure more than a second or two can be said to be a time exposure. See: Bulb and Reciprocity Failure

Tripod. A three legged camera support. A good test: extent the tripod to its maximum and gently rock the head to see how sturdy it is. You will soon see the trade off of weight, cost and steadiness. For travel get a small, light one. See: monopod.

Under Exposure. This exists when your photo has not been given enough light. As with over exposure this can be caused by a shutter speed that is not open long enough, that is s shutter speed too fast for conditions. And, or, a f-stop, lens opening, that is too small. The too fast shutter? Well, think about it. If the shutter is not open long enough, it will not admit enough light, right? And the aperture? Well, if set to an opening that is too small to admit enough light the photo is light starved. Yes, now you've got it. Too little light, too little exposure. Don't forget exposure is time and intensity. You could say that these shots resemble a black cat in a coal mine. See Over Exposure and our white cat analogy.

Wise Angle Lens. This lens makes the subject appear farther away that it actually is and shows you a wider picture than a normal lens.

X-Ray Photography. The exposing of photographic plates or film with x-rays. This is also called Radiography when a radioactive sources is used as a source of Gamma radiation. Gamma radiation and x-rays are the same radiation they differ only in their manner of production. X-rays are created in a x-ray machine by the acceleration of electrons to high speed. The electrons are then directed to a target which they hit at great velocity. The energy they loose when they hit the target is given off as electromagnetic radiation, or as x-rays. That's what x-rays are. Gamma radiation is produced through the decay of radioactive elements. These elements give off energy as they decay into a lower energy element.

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