LED lighting has been around for many years and is just now really coming into its own. For years, the Light Emitting Diode was simply used as an indicator or display light in various small-scale applications. Think of those old Texas Instruments calculators, or the blinking VCR light.
LED is a solid-state technology. This means there is no glass bulb, no pressurized gases, no mercury and no burning filament. In the traditional bulb, heat was the main result while light stood as a mere by-product of electrifying the filament.
With LED technology, what you have is a circuit board and a computer chip. The properties of the chip create light that is generated and focused through a plastic diode to create light. Depending on the chip and materials used, different colours in the colour spectrum can be created. Early on the easiest colour to create was red, which is why your calculator and VCR had red display lights rather than any other color. For many years, there were no advancements in LED technology and very little change in lighting technology over all; changes that did occur were mostly just plays on a theme. Metal halide, fluorescent, etc. were all just different ways to do the same thing with different effects.
In recent years, LED technology has completely changed and reinvented the light bulb and the way we think about lighting in general. This was not really possible prior to the technological revolution of the ‘90s and the rapid advancement of the microchip. The same advancements that spurred the computer to reach dizzying levels of efficiency have also done the same for the LED. Just as computers have become faster and cheaper, LED lights have become brighter, smaller, less expensive, and more sophisticated.
There are quite a few advantages to using LEDs. Generally they are heatless, use 90% less energy, and last ten years. They are also smaller and do not contain any dangerous chemicals like mercury. They can readily be put in places that have always been too small or out-of-the-way for many incandescent lights, as well as in places that were always very dangerous or difficult to get at. Also, the more sophisticated LED apparatuses like wall washers and spotlights are DMX-controllable, which means they can be used in some really impressive ways.
The bottom line is that LED’s are easier and safer to use than all previous lighting technologies. Plus, LEDs will save you money by consuming less power, lasting much longer, and generating much less heat, which in turn combine to result in lower climate control costs.
Today there are hundreds of different products available in varying brightness levels, colour temperatures, and sophistication levels to meet every lighting need – from those of an architect’s latest high-rise condo project, to those of a rural homeowner’s kitchen renovation. There are replacement bulbs for screw-in Edison-style bulbs and for nearly every style of Fluorescent. Plus, the LED replacements are of the “plug and play” ilk with no other modifications needed. There are also many different types of architectural lighting, such as wall washers and spotlights.
Finally, our most popular piece of LED lighting is the light bar, which can be used anywhere. From display cases to under-cabinet lighting, our light bars offer a novel (and cost-effective!) approach to accent lighting. LED lighting is quickly replacing all incandescent lighting applications.
In the past, we have generally referred to the brightness of a bulb in terms of its wattage, or the amount of power that the bulb uses (or energy consumes). Because of the disparity between incandescent and LED technologies, we have to change our language a bit in order to account for progress. When referring to brightness, we now find ourselves comparing lumens (see Q: What is a lumen?). However, when comparing LEDs with incandescents, there is no easy mode of comparison because the typical incandescent is projecting light in 360 degrees – everywhere, not just where you need it. Because LED lights are directional, they focus all the light they generate exactly where you want it, and nowhere that you don’t. Another consideration is colour temperature. In the past, this has been very difficult to control because you basically got whatever colour your particular bulb produced. Typically this was a Warm White (about 3000K) if you had an incandescent bulb, and a Cool White (around 5000K) if you had a fluorescent bulb. Because the LED is an intelligent, solid-state technology, we are able to produce LEDs that not only produce Warm White and Cool White, but are able to produce up to 16 million different colours, each a different temperature.
Lumen is amount of light emitted from light source. According to Wikipedia, “If a light source emits one candela of luminous intensity into a solid angle of one steradian, the total luminous flux emitted into that solid angle is one lumen. Alternatively, an isotropic one-candela light source emits a total luminous flux of exactly 4π lumens. The lumen can be thought of casually as a measure of the total amount of visible light emitted.” For example, a standard 100 Watt incandescent bulb emits about 1500 lumen.
Lux is lumen per square meter. According to Wikipedia, “The difference between the lux and the lumen is that the lux takes into account the area over which the luminous flux is spread. 1000 lumens, concentrated into an area of one square meter, lights up that square meter with a luminance of 1000 lux. The same 1000 lumens, spread out over ten square meters, produce a dimmer luminance of only 100 lux.”
When projecting material in its WXGA native resolution you can expect more than an admiral performance, with clear text and graphics. However, despite its ability to display resolutions as high as 1280 X 800, if you feed it resolutions higher than SVGA you will experience some loss of detail due to compression algorithms.
“JPEG” is an acronym for the Joint Photographic Experts Group. In computing, JPEG (pronounced jay-peg) is a commonly used method of compression for photographic images. A Baseline JPEG is a file stored as one top-to-bottom scan of an image, unlike the more complex Progressive JPEG. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality. JPEG typically achieves 10:1 compression with little perceptible loss in image quality. JPEG compression is used in a number of image file formats. JPEG is the most common image format used by digital cameras and other photographic image capture devices. THE BASELINE JPEG IS RECCOMENDED FOR THE LED300.
A simple or “baseline” JPEG file is stored as one top-to-bottom scan of the image. Progressive JPEG divides the file into a series of scans. The first scan shows the image at the equivalent of a very low quality setting, and therefore it takes very little space. Following scans gradually improve the quality. Each scan adds to the data already provided, so that the total storage requirement is roughly the same as for a baseline JPEG image of the same quality as the final scan (basically, progressive JPEG is just a rearrangement of the same data into a more complicated order).
The aspect ratio of an image is the ratio of the width of the image to its height, expressed as two numbers separated by a colon. That is, for an x:y aspect ratio, no matter how big or small the image is, if the width is divided into x units of equal length and the height is measured using this same length unit, the height will be measured to be y units. For example, consider a group of images, all with an aspect ratio of 16:9. One image is 16 inches wide and 9 inches high. Another image is 16 centimetre wide and 9 centimetres high. A third is 8 yards wide and 4.5 yards high.
DivX is a brand name of products created by DivX, Inc. (formerly DivXNetworks, Inc.), including the DivX Codec which has become popular due to its ability to compress lengthy video segments into small sizes while maintaining relatively high visual quality. There are two DivX codec’s; the regular MPEG-4 Part 2DivX codec and the H.264/MPEG-4 AVC DivX plus HD codec. It is one of several codec’s commonly associated with “ripping”, whereby audio and video multimedia is transferred to a hard disk and transcoded.
Resolution refers to the number of pixels in an image. Resolution is sometimes identified by the width and height of the image as well as the total number of pixels in the image. For example, an image that is 2048 pixels wide and 1536 pixels high (2048 X 1536) contains 3,145,728 pixels (or 3.1 Megapixels). You could call it a 2048 X 1536 or a 3.1 Megapixel image. As the megapixels in the pickup device in your camera increase so does the possible maximum size image you can produce. This means that a 5 megapixel camera is capable of capturing a larger image than a 3 megapixel camera.
The computer screen you are looking at right now is set at a particular resolution as well. The larger the screen, the larger you likely have your screen resolution set. If you have a 17″ monitor, likely you have it set at 800 X 600 pixels. If you have a 19″ screen it is likely set at 1024 X 768. You can change the settings but these are optimum for those screen sizes. Now, if your monitor is set to 800 X 600 and you open up an image that is 640 X 480, it will only fill up a part of your screen. If you open up an image that is 2048 X 1536 (3.1 megapixels) then you will find yourself moving the slider bar around to see all the different parts of the image. It just won’t fit. Add to that the fact that the computer monitor has a finite number of pixels per inch available (like 72) so if you are going to display your image on a monitor only, you would want to drop the quality down to 72 to save file space. If you are going to put your image on a webpage or email it to a friend then you will want to first make it a useful size. Not too big, not too small. Maybe 200-300 pixels high would be a nice size. You can also reduce the size of the file (not necessarily the size of the image) so it loads faster.
In addition to image size, the quality of the image can also be manipulated. Here we use the word “compression”. An uncompressed image is saved in a file format that doesn't compress the pixels in the image at all. Formats such as BMP or TIF files do not compress the image. If you want to reduce the “file size” (number of megabytes required to save the image), you can choose to store your image as a JPG file and choose the amount of compression you want before saving the image. JPG compression analyses images in blocks of 8 X 8 pixels in size and selectively reduces the detail within each block. At higher compression rations, the block pattern becomes more visible and there may be noticeable loss of detail, especially when you attempt to make prints larger than recommended. The subject and pattern in the image is also a factor. For example, a picture of the blue sky can be compressed quite a bit without any noticeable effects but a picture of a colourful bird would “pixelate” quite quickly. By using JPG compression, you can keep the physical size of the image the same and reduce the amount of disk space required to store it but you will be sacrificing the quality of the image.
Well, the true answer is you can make as big a print as you want but very quickly you will start to see “blocks” (pixelization) and the quality will drop off. To maximize the capability of your printer, you should print a picture a size that the printer can handle. Here we introduce a new term “dots per inch” or “pixels per inch”. Example, you have a 640 X 480 image and you want to print it at 200 dpi (dots or pixels per inch). 640 divided by 200 equals 3.2 and 480 divided by 200 equals 2.4 so if you print this picture at 3.2″ X 2.4″ you will get a print with 200 dots per inch. We recommend 200 dpi as a minimum for good quality prints. Now, let’s work one of these problems backwards. Let’s say we want to print an 8 X 10 inch picture at 300 dpi. What resolution must we have to do this? 300 times 8 is 2400 and 300 times 10 is 3000. So we would need a 3000 X 2400 image to do this. Let’s see, 3000 X 2400 is 7.2 megapixels! That would be one very nice digital camera and one very large file, especially if it wasn't compressed.
Determine what your use for the image will be. Will you want an 8 X 10 inch print or will you only be emailing it to a friend? Choose the image size and amount of compression to meet these needs and capture at the least possible compression. The trade off is large file sizes will fill up your media quicker but, later on you can dump the original uncompressed image to a CDROM or hard drive, compress the original and resave it with a different file name. You cannot expand a previously compressed file so keep the uncompressed (or low compressed) file as a master.
This will work for images on a JumpDrive or images viewed directly from your computer, laptop or tablet. The first step is to choose an “Image Viewing” program to open your images up with. We suggest the program “FastStone Image Viewer,” but there are a number of programs available. Once downloaded from the internet, you are set to begin previewing your images. Find the saved images you are going to view; whether they are on your desktop or on a JumpDrive it does not matter, this will work the same either way. Once you have selected an image to resize, make sure the image is in a “full-screen preview mode” (the image is the only image on the screen). This can be achieved by double clicking the image. Then, right click with your mouse on the image and select “Edit” from the drop-down menu. This will bring you to the options of “Resizing” or “Resampling.” These are 2 completely different options and for this purpose resizing is the correct choice. Once the resizing option is selected, a dialog box will appear with “image dimension options.” The simplest way to change your image size is to change the dimensions for the “Standard” option. This will change your image’s print dimensions without changing your “Dots Per Inch” (DPI). This is what defines the difference between resizing and resampling (but that’s another issue for a different FAQ). Dimensions in the option box for “Standard” will generally range from a reduced size of 120 x 90 up to 2272 x 1704. You can play around and adjust the size to see what will work for you. Make sure to save the newly resized image under a different name as the original so as not to permanently change your original image. Once you have found the desired size, the dimensions can further be enlarged or reduced by simply physically moving the projector closer in or farther out from the surface you are projecting on.