| LZW | (Lemple-Zif-Welch) Lossless compression; supported by TIFF, PDF, GIF, and PostScript language file formats. Most useful for images with large areas of single color. |
| Lux | Unit of light |
| luminance | photometric measure of the density of luminous intensity in a given direction. It describes the amount of light that passes through or is emitted from a particular area, and falls within a given solid angle |
| LS | (Long Shot) A long distance shot which is usually wide angle |
| Low Pass Filter | Most digital SLR cameras employ a Low Pass Filter (LPF) or Anti-Aliasing (AA) filter in front of the imager to help eliminate color aliasing (moire) problems |
| Lossy | denotes a loss of data during Image file compression. Only occurs when higher compression rates are used. |
| Lossless | techniques compress the file without removing image detail or color information |
| Lithium Ion | rechargeable batteries with negligible memory effect and offer about twice the capacity of Ni-MH batteries |
| Lines Of Resolution | A measure of horizontal resolution in a video system, measured by the number of vertical black lines that can be resolved on a white background. |
| Linear Editing | Editing with analog formats |
| Lexan | An extremely tough polycarbonate plastic, usually transparent, used to make underwater housings. 'Lexan' is a trademark of the General Electric corp. |
| Levels | The Levels dialog box lets you correct the tonal range and color balance of an image by adjusting intensity levels of the image's shadows, midtones, and highlights. The Levels histogram serves as a visual guide for adjusting the image's key tones |
| Lens Speed | Maximum aperture diameter, or minimum f-number, of a lens controlling the amount of light admitted through the lens |
| LED | Light Emitting Diode. |
| Leak Detector | A device you can fit inside an underwater camera housing to audibly (and sometimes visually) warn of the ingress of water. |
| Lead lines | using lines as a compositional device to lead the eye into the subject |
| LCD | Liquid Crystal Display. Such displays on the back of a digital camera allow you to preview images. These usually use TFT technology. Also used to display info on film cameras. |
| Layer masks | Used to obscure entire layers and layer sets. By using masks, you can apply special effects without actually affecting any of the original data on that layer. After you’ve found the perfect effect, you can then apply the changes. The changes can also be discarded. Layer masks are created using the painting and selection tools. |
| layer mask | You can obscure an entire layer or layer set, or just a selected part of it, using a layer mask. You can also edit a layer mask to add or subtract from the masked region. A layer mask is a grayscale image, so what you paint in black will be hidden, what you paint in white will show, and what you paint in gray shades will show in various levels of transparency. |
| Layer | Layers are like transparencies, which are clear plastic sheets of material that can be printed on. The transparencies can be printed and stacked on top of one another to form a complex picture, and single transparencies can be removed from the stack for editing or removal |
| Latitude | Ability of the film or device to record the brightness range of the subject |
| Lasso | There are three Lasso tools: the Lasso tool, the Polygonal Lasso tool, and the Magnetic Lasso tool. The first two choices let you draw around an object using curves and line segments, respectively, and the third lets you draw around an object and have the drawn lines snap to the object (based on calculations determined by color differences in the object and the background). |
| Lanyard | A short piece of rope or line used as a handle or tied on to some other object. |
| Lab color | The L*a*b color model is based on the model proposed by the Commission Internationale d'Eclairage (CIE) in 1931 as an international standard for color measurement. In 1976, this model was refined and named CIE L*a*b.Lasso tools: |
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