Apochromatic Lens (APO Lens)
Apo lenses are sharper and have better color contrast because they do a better job of focusing different colors on precisely the same plane. Optimum results are achieved in analog color darkrooms with apo lenses. High-end film scanners such as the Imacon achieve better scans in part because of internal apochromatic optics. Apo lenses are available for some cameras.
Archival is one of the more ambiguous words in the photo art world. Ansel Adams defined it as the ability of a print to last 100 years with little perceptible change. The Society of American Archivists defines Archival Media as "resistant to deterioration or loss of quality, allowing for a long life expectancy when kept in controlled conditions." Storage and display conditions, materials and how they are used, affect the lifespan of a photograph. Most manufactures claim their materials are archival. Independent testing of photographic longevity is more reliable.
Pronounced as the word "bow" followed by "kay" or rhyme with the word okay. But don't stress on correct pronunciation of this Japanese language word for fuzzy or blur. Bokeh is affected by the f-stop, focal length and type of lens. Creating out-of-focus areas in Photoshop is not the same quality as in-camera occurring bokeh.
C-Print or Chromogenic Print
A photo print created on light-sensitive color paper traditionally from a color negative, but now C-prints can be created from a digital file (see Digital-C print). This still widely used process was popularized in the sixties for snapshots and commercial use. In the early 1990's galleries and museums readily began to show C-prints and continue to do so to this day. Archival quality of this paper suffers if processed incorrectly. C-Prints are sometimes incorrectly confused with Cibachrome.
Color negative film and C-prints are chromogenic materials. The word is rooted in the Greek and Latin words for color and creation. The color dyes in chromogenic materials are formed during the photographic developing process. See C-print.
CMYK Color
Short for Cyan-Magenta-Yellow-Black. This color model is designed for large offset printing presses, but inherently lacks the ability to produce all colors correctly. Photographers get better results working in RGB. Digital-C and inkjet printers are designed for RGB input. Of interesting note, inkjet is an expanded CMYK process but associated printer software handles RGB files better. See RGB and LAB.
Color Correction
The act of altering the color, density and contrast of a digital or analog image. Color correction is a learned skill. Not everyone can color correct well. Seven percent of men and less then a half percent of women have at least mild color-blindness. Not to be confused with "color management."
Color Management
The applied process and ensemble of technology to ensure consistent, accurate, and predictable results when printing digital photographs. See our color management page. Good color management requires correct use of ICC profiles and monitor calibration.
Color Profile
An information file intended to keep color consistent between devices such as your monitor and a printer. Misapplied and missing profiles will lead to mismatched color. Profiles are applied to equipment and software to keep color uniform. Proper use of color profiles is a crucial part of color management.
Color Temperature
Measured in Kelvin degrees. An incandescent household 40 watt bulb is approximately 2900K, light from midday sun with no clouds is 5500K, and candle flame can be as low as 1000K. The higher the number the cooler or bluer the light. Photos for commercial use are viewed under artificially created 5500K light. It may be advantageous to view prints under warmer light if showing in a gallery or museum. Correct monitor color temperature settings are a crucial part of color management. Final print color should be analyzed under the same conditions under which they will be shown whenever possible.
Digital C-print
A C-print made with a digital photographic printer such as a Chromira. Other examples of digital-C printing equipment are Lightjet, Lambda and Polielettronica. Sometimes the brand name of the equipment has been used to describe the print process. Equipment quality has evolved. ZBE-Chromira is the only company still producing and innovating digital-C printers.
The resolution of a digital print is expressed in Dots Per Inch, or DPI. Not to be confused with PPI which refers to onscreen resolution.
Drum Scanner
Drum scanners create digital files from a negative, transparency or print. A few models will outperform the current Flextight-Imacon scanners, but only if the drum scanner operator is highly skilled. Unfortunately it is rare to find such a technician. Art objects and unique prints should not be drum scanned, as the drum rotation can damage fragile materials.
Flextight Scanner
Imacon Flextight scanners have incredible resolution and graphic range. Imacon scanners were re-branded and cosmetic changes were made after Hasselblad and Imacon combined into one company. Imacon-Flextight scans sometimes get a bad rap because of operator ignorance of the fine points of the software. Just like all drum scans, Imacon-Flextight scans require specific work in Photoshop to be usable.
The limitations of a given color space or device. Gamut errors result from bad profiles or working techniques. Gamut increases as printing technology advances, but wider gamut prints do not always equal better print quality.
Pronounced zhee-CLAY, this marketing term applies to high quality inkjet prints. Giclée prints are archival pigment prints made with inkjet equipment. The word was coined by Jack Duganne in 1991, an early fine-art inkjet printer.
JPEG or jpg
This file format for images is commonly used to display photos online because the file size is smaller. Jpeg files do not have the inherent optimal quality of tif or psd files, but may possibly still be good for printing if saved as a "highest quality" jpg.
LAB Color
Correctly referred to as L-A-B, not the word lab. Stands for Lightness and opposing color A and B channels. It is based on the function of the human eye. Some photographers feel they have better control in LAB, while most initially find it perplexing to work with. It is useful in specific situations to enhance contrast and increase the color palette of an image. See RGB and CMYK.
A measurement of light, derived from the Latin word for light.
The phenomenon in which colors match under one light source but do not match under another source. Metamerism can occur with inkjet prints but does not occur with digital C-prints. Pigment reaction to ultraviolet light is the cause of metamerism.
Print Ready
A file entirely prepared by the client and submitted to a photo lab "ready to go". Print ready files give photographers more control over print quality. Other terms for print ready include pre-flight and direct to print. Print ready philosophy only works if the photo lab is capable of consistent accurate printing.
RGB Color
Short for Red-Green-Blue, RGB is the dominant color model in the photographic industry. RGB allows for more color control than CMYK. See LAB and CMYK.
Short for Raster Image Processor. RIPs are software that make an image file understandable to a printer. Print drivers included with all computers and printers are simple RIPs. Optimum results are achieved on professional grade printers with third party expensive RIP software.
The intensity of a given color. A total lack of saturation results in gray scale images. Digital capture and scanning often tends to be oversaturated, especially for skin tones.
Soft proofing
The technique of using your monitor as a proofing device instead of making a test print. In theory a soft proof shows on the monitor exactly what a final print will look like. Quality calibrated monitors and good color management make soft proofing possible. Soft proofing eliminates the need for test prints for most people.
Tagged Image File Format. An uncompressed image file format. Newer technologies have allowed for LZW compression of tifs. LZW compression will make files smaller with no image quality loss.

Questions or comments about the glossary?