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February 28, 2006
LED Flashlights
What are LED flashlights, and why should I care?
LED flashlights use an electronic component called a white light-emitting diode (LED) instead of a traditional incandescent bulb as a light source. LED flashlights enjoy several advantages over incandescent lights:
- LED flashlights typically have longer battery life than traditional flashlights, which waste a lot of their energy via heat.
- There is no need to replace the bulb during the typical lifespan of light, as LEDs will last up to 100,000 hours (or 11 years of continuous use).
- LED flashlights are much more shock-resistant than traditional flashlights, which rely on relatively fragile bulbs to produce light.
- The small size of the LED “bulb” allows for great flexibility in design.
The company which makes the popular Maglite ® flashlight has just announced that it will be joining the party with its MAG-LED TM line of flashlights, providing further evidence that LEDs are here to stay.
Are all flashlight LEDs the same?No. There is wide variation in the quality of LEDs used in flashlights. Technology is constantly improving, so an LED flashlight from a few years ago will probably not be as bright as current models. Even among new models there are significant differences in light output.
If brightness is critically important, you may want to look for one which is rated at 1 watt (1W) or greater. Also, flashlights which use Luxeon LEDs are reported to be significantly brighter than standard LEDs. Visit the Web sites listed in the Resources section for more information.
What specialty LED flashlights are available?
The technology used in LED flashlights has been adapted into many forms. One common variety is the keychain flashlight. LED headlamp flashlights are useful when you need lighting with both hands free. Finally, LED technology has been used in camping lanterns, providing a safer and smaller alternative than fuel-based lanterns.
Why does the light from some LED flashlights seem blue?
It’s true that LED flashlights may appear to have a blue tint compared to traditional flashlights, but in part this is because we have grown accustomed to the warm yellow glow of incandescent lighting. Ordinarily this blue hue doesn’t affect the usefulness of LED flashlights, except where color accuracy is essential.
What kinds of batteries should I use?
Common battery sizes like AAA, AA, C and D cells are prevalent in LED flashlights, but others, such as CR123, are sometimes required. Alkaline batteries are the most common type used, but you may want to substitute lithium cells for optimal battery life and better performance in cold weather, though they are relatively expensive. The most popular type of rechargeable battery in today’s market, nickel metal hydride (NiMH), may be a poor choice for flashlights which receive only sporadic use, as NiMH cells have poor shelf life, spontaneously losing about 30% of their charge per month.
What things should I consider when purchasing an LED flashlight?
- Size is the first factor to consider. While larger flashlights will provide longer battery life, they can be bulky. A small flashlight that you always carry is better than a large one you leave at home.
- Look for a flashlight with a regulation circuit to make the brightness stay constant over the life of the batteries, rather than gradually dimming over time. You may need to read reviews or discussion group postings to learn whether a particular flashlight is regulated. See the Resources section for relevant Web addresses.
- Determine whether you need a spot or a flood beam (sometimes called a spotlight or floodlight). A spotlight has a very narrow beam of light which is tightly focused on a subject. In contrast, a floodlight is very broad, spilling a lot of its light to the sides of the subject. If you’re trying to illuminate a street sign from far away, a spot beam is best, but if you’re trying to light up the entire room or something very close, go for a flood beam. Flashlights often represent a compromise between the spotlight and floodlight styles.
- The type of switch will vary. Some people prefer a simple push-button switch, while others prefer a rotating switch. In addition, some switches toggle between on, off and strobe (flashing).
Are there any downsides to this technology?
The biggest problem with LED flashlights is cost. Compared to inexpensive incandescent flashlights, which can often be found for less than $10, LED flashlights carry a significant price premium, frequently costing $15—$30 for a two-battery flashlight. Other potential problems, like an extremely blue beam, may be avoided by doing research in advance using the sites listed in the Resources section.
Final Thoughts
For ordinary household use, LED flashlights are hard to beat. Their mix of durability and excellent battery life make them easy to recommend. In fact, you may want to pick up more than one to ensure that you always have the right light for any occasion.
Resources
Web sites providing reviews and/or discussion forums for LED flashlights.
- Flashlight Reviews: http://www.flashlightreviews.com/index1.html
- The LED Museum: http://ledmuseum.home.att.net/
- Torch Reviews: http://torchreviews.net/home.htm
- Candlepower Forums: http://www.candlepowerforums.com/vb/ (use the search function to find specific flashlight models)
Using the information within these sites, you can determine:
- Whether a flashlight contains a regulation circuit
- How long its battery life will be
- Whether the flashlight’s beam is spot or flood
- The color of the beam (blue or white)
- How it compares to other flashlights in its class
- If there are any easy modifications to improve the flashlight
- If there are any sales on flashlights this week
With this information in hand, you can make an informed choice on your next flashlight purchase.
Posted by moetting at 11:53 AM | Comments (0)
February 2, 2006
Portable Video Players
Much in the way that MP3 players let you listen to music away from home (see Tech Talk: Vol. 1, No.1), portable video players allow you to watch recorded television and other videos on the road. These devices, which range in size from a deck of cards to a paperback novel, have been available for a couple of years, but sales have been hampered by high prices and the lack of a simple way to get videos to watch. The screens are small, typically 2.5" – 4", though at least one measures 7". Even though video takes up much more storage space than audio, portable video players have the capacity to store many hours of TV shows and movies.
In recent months, these gadgets have started to gain momentum. Apple made a big splash in the marketplace in October 2005 by adding video capabilities to certain models of their popular iPod digital audio player line. Then in January 2006, the Zen Vision:M by Creative, a veteran of the portable video market, received a “Best of Show” selection by ZDNet at the 2006 Consumer Electronics Show (CES) in Las Vegas. If the number of video players announced at CES is any indication, 2006 could be the year that these portable video devices really take off.
How do I get videos to watch on my player?Without question, the easiest way to do this is to purchase pre-converted television shows or movies from an online source. Apple’s popular iTunes store offers many popular television programs for $2 per episode. Other sources for online video include CinemaNow and MSN Video Downloads, though both of these sites will only work on Windows-based portable video players.
If you’re lucky enough to have a TV tuner in your PC, you have another potential source for video content. Using software which turns your computer into a digital video recorder (e.g. Frey Technologies’ SageTV ), these computer TV cards save television programs to your hard drive. You then convert these files to a compatible format using the software which came with your video player. This process, called “transcoding,” is very time-consuming, often taking one to two times as long as the original program. But once you get accustomed to the conversion process, computer TV tuners can be a great source for video material.
What about DVD movies? Can I convert them?
Can you? Yes, with the proper software. Is it legal to do so? Probably not. The Digital Millennium Copyright Act of 1998 (DMCA) has a provision which makes it a crime to use software tools to get around the copy protection inherent in DVD movies and other protected digital media. This means that efforts to convert content from a DVD you own to a portable video format would most likely be illegal under the DMCA. For a summary of the DMCA published by the U.S. Copyright Office, see http://www.copyright.gov/legislation/dmca.pdf. Despite the DMCA restrictions, a few software companies have released products which will convert DVD video. Use Google to search for “DVD conversion ipod” or “video conversion portable wmv” for more information.
What kind of battery life should I expect?
Generally speaking, the smaller the player, the lower the battery capacity. The battery life of the relatively chunky Creative Zen Portable Media Center is seven hours, while the svelte new iPods will last only two to three hours per charge.
Can I record directly from a VCR or cable TV?
The majority of the players on the market cannot, but a few can. Archos, for example, makes several popular models which can record.
Do they have any other special features?
Many players have the ability to play photo slideshows and nearly all will play digital (e.g. MP3) music. Another common feature is video output, where you can see your videos on a full-size TV, though the video quality may be mediocre when enlarged.
Are there any downsides to this technology?
There are a few issues with these players. First, despite the expanding video inventory of sources like Apple’s iTunes, you may still have a tough time finding things that you want to watch. If this situation improves, portable video players will make a lot more sense for the average consumer. Next, price may be a barrier. Expect to spend at least $300 for a respectable video player, but a top of the line model could set you back up to $1,000. Finally, there is no single standard video format which works on all players. Before you buy a player, make sure you read its technical specifications to determine what video format(s) will work. Ideally a player should be able to support many different formats, but few models support more than two or three without the time-consuming conversion process.
Final Thoughts
A portable video player may be right for you if:
- You’re a TV lover with time to spare (e.g., you spend a lot of time traveling by air or train).
- You can find enough things to watch from an online store like iTunes, or by converting TV recordings from your computer or TiVo.
If you don’t fall into both of these categories, you may want to wait until video content becomes very easy to find and competition drives the price of players down.
Resources
General Information
News Sites
- DAP Review: Covers digital audio and video players — frequently updated.
- PMP Maniac: Another good source of information on portable media players.
- PVP for You: Good, but sporadically updated.
Individual Product Reviews of Popular Players
- Ars Technica’s review of the 5th generation iPod with video.
- ZDnet’s review of the Archos AV500, a portable video player which can record from a VCR or other video source.
- Good Gear Guide’s review of the Cowon iAudio A2, another recording portable video device.
Posted by moetting at 2:27 PM