OK, so you've decided what you want to buy - the question now is where to buy it from! There are two things to look for - price and service. Price is easy - you're after the best possible deal, but sometimes that comes at a price - lack of after sales support. Here's a very interesting article about the potential pitfalls, and a list of things to look out for:
Bear in mind that goods bought in one country may not be compatible with your own country - check things like the power requirements, video standards and mobile phone network information carefully before you buy. Remember to find out what the warranty situation is, some manufacturers will only service goods bought in the US if they're returned to the US - and a few companies won't honour warranties unless you buy from an authorised dealer! Check what the situation is, and test goods before you leave the area... If you decide to buy online remember that you have to include the cost of shipping and more importantly any taxes you'll be liable for. For example (at time of writing) if you buy from the US and have your goods sent to the UK then you have to pay shipping, and then you'd be liable for 12.2% import duty and then 17.5% VAT on top of that! Not quite the bargain you were expecting was it? ;-)
Generally things are cheapest to buy either online in the US, or in places like Singapore - in other words where competition is relatively fierce. So, how much should you pay? The first thing to do is see if you can find some prices online:
Often those sites will give you the best prices available - but remember they don't search everywhere, sometimes there are even better deals out there.. OK, so you have an idea of what you should be paying - if you're in the US then you could just buy online, but remember to use your common sense - be cautious when dealing with a company that's new to you, and remember that scammers can have excellent feedback as well all it takes is some dishonesty... If a price seems to good to be true, then at least consider the possibility that it might not be true ;-) In most countries there's a certain amount of flexibility in pricing - even if you're in a country where haggling is not customary. If you're in an area with a high concentration of similar shops (like Funan IT mall) ask each store what the best price they can do is, make a note and move on. Once you have the best prices return to the stores that gave them and see if they're prepared to better them!
If you're thinking of buying abroad consider Singapore. There are several excellent locations - Funan IT mall and Sim Lim Square are the major places, although if you're after high-end camera equipment Cathay Photo in Peninsula Plaza might be a better bet! Generally places in the major shopping areas of Singapore are reasonably reputable. However you should always check that goods are new and actually in the box before you leave the store.
Online auction scams:
Another source of low prices are the online auctions like eBay. There are some additional things to beware of when buying from auction sites on the internet. Again if a price seems too good to be true think carefully about why the item is so cheap! Some possible scams and problems are linked here:> Scam tricks users into stealing @ zdnet.com
> The risks of online auctions @ photonotes.org
Make sure you're aware of the risks before you part with your money! According to this article at TheInquirer there was a loophole in eBay which allowed sellers to forge their own feedback - whilst I'm sure that loophole has been plugged dishonest people will always be looking out for the next opportunity...
Something else to consider, is the possibility of counterfeit goods. Memory cards and batteries are often encountered, but there are rumours of fake cameras/camcorders/phones floating around too. In Morocco I saw a number of 3800mAh Sony NiMH AA batteries for example. The funny thing is, Sony doesn't manufacture anything above 2500mAh yet. Reports of fake Kingston, Sandisk and Sony cards are particularly common, here are a couple of examples:> Fake Sandisk CF cards @ martybugs.net > Fake Sandisk SD cards @ members.shaw.ca
- Back to the top of the page -
Note: To transfer MP3 music files onto a player you need a computer of some kind. You will also need either some CD's and a CD-ROM (or DVD-ROM) drive and/or an internet connection to convert the music into a form your player can use. Be aware that there are possible legal implications in doing this, so I strongly recommend that you find out what they are before you start - particularly if you intend to download music from the internet. Also check that the player you're interested in is supported by your computer platform - most are rather Windows-centric, with the exception of the Apple iPod which has a Mac bias.
Important: If you're planning to use files from an online music store, bear in mind that there are a number of different formats in use - for example Apple iTunes uses AAC, Sony Connect uses ATRAC3, and Walmart/Napster/etc use WMA. If you've already downloaded music in one of those formats you'll need to choose a player that supports it. You might find it better long term to buy CDs and encode them yourself, although you should check that it's legal to do in your country before doing so! Also remember that not all artists are available from each store, so if you're planning to download music, check that your favourites are actually available and make your player decision based on that.
There are three main types of MP3 player - those that use flash memory, those using removable discs and those based on hard-disk technology. First choose which type you're interested in:
|Flash based||Removable disc based||Hard-disk based|
|Change storage:||Some models||Yes||No|
|Max capacity:||512Mb-8Gb||650Mb (4.3Gb with DVD)||4-200Gb|
|Skip potential:||Will not skip||Low>High||Lowish|
Note: 1Mb = ~1minute of near CD quality music. 1Gb = 1024Mb.
Almost all MP3 players can play MPEG1-layer3 (aka MP3) files, but some support other formats as well - WMA (Windows Media Audio) offers better sound quality for the same size of file, which means you can store more music in the same space. MP3 in this context is what's known as a codec, which in turn is an abbrievation of "coder-decoder", i.e. the way the music is compressed. As technology advances so do the codecs available. Choosing which codec to record with and a suitable bitrate is very important, there's a good article on your options here:
> Audio codec comparison @ extremetech.com
> 128kb/s codec comparison @ rjamorim.com
Some players have a built-in battery that cannot be removed - this is a problem if you forget to recharge, the battery becomes faulty, or you run out of power. Since the battery technologies in use are very similar to those in digital cameras I suggest you look at the Digital camera section of the FAQ for more information.
Flash based players
These can be divided into two broad groups - those that use removable memory cards, and those that don't. Generally removable memory cards are the best option for travelling, since you can buy a number of cards and change them to suit your mood. The usual range of memory cards are used, for more information about the options I suggest you head back over to the Digital camera section of the FAQ. My favourite player in this category has to be the:
Removable disc players
The most popular type of removable disc player uses CD-R (and CD-RW) to store MP3 files, they can also playback standard music CDs too. They're slowly fading from the market as flash players get ever cheaper though. In addition to CD, there are other types of removable discs - usually chosen for size, but they aren't anything like as popular. There's even a DVD based model available in Asia too, the Sony MPD-AP20U. You need to create a CD on your computer if you wish to use the MP3 playback feature though - one MP3 CD can contain nearly 11 hours of compressed music. As with normal portable CD players check that battery life and anti-jog features are suitable for your needs...
Hard disk based players
There are now two different types of hard disk players, "full size" and miniature - full size units can offer massive storage capacity in a very portable size, miniature devices have now been obsoleted by larger capacity flash based players.
If you don't want to change discs, you need something a less wide than a CD based unit, or you simply want one unit that does it all, then a hard disk based player is probably your best choice. Some can even act as backup storage for your digital camera, see the Storing Digital Images section of my On The Road page for more information! Currently the maximum capacity is 200Gb - enough to store a startling 138 days of continuous non-repeated compressed music! Unfortunately the main drawbacks of these units tend to be in the battery area - usually they use proprietary batteries, and some (like the iPod) have a non-removeable rechargeable battery built-in. The good news is that Apple now offer to replace the battery for 65USD - but they delete all data from them during processing... If you're on the move you need to have an idea how you're going to recharge them - if you can't power it, it's just an expensive paperweight.
- Back to the top of the page -
It's important to remember that all computing information has a short lifespan, what might be the most important hardware at the time of writing could be obsolete within a matter of days. For your reference this section was last updated 14Jun2007.
Note: Windows Vista has arrived. Whilst most current new laptops will run Vista in basic mode, if you want the high end features such as the Aero-Glass GUI to run, you'll need to invest in a machine with a higher performance graphics chipset - so look for the "Windows Vista Premium Ready" logo. Some machines may be Premium ready, but not marked as such yet - if you think a machine may qualify, check it against the specs on the Microsoft website:> Windows Vista hardware requirements @ microsoft.com
Unlike desktop computers, which are usually upgradeable in most respects, there are usually very few parts of a laptop that can be upgraded, so it's vital to choose the specification that's right for you now, and if possible try and consider your future needs too.
I tend to view the market as consisting of three major types, and they're size related more than anything. Firstly there are the ultraportable machines, lately branded as UMPCs they can be very small, and offer reasonable battery life - but they aren't the fastest machines, and they can be expensive. Next are the machines I call mid size - they're bigger than the true ultraportables, but they're still reasonably portable - they can be quite a bit cheaper than the ultraportables, they'll often be marketed as "slim and light" or something similar. The final category are the desktop replacement machines - they're big, relatively heavy, they are generally power hungry - but they offer the largest screens and the best performance. The first thing you need to do is decide what you need a laptop for, this should define the size and features that you need. If you're travelling a lot, then obviously smaller (and lighter) is generally better.
Most folk buy their laptops ready built, but these days, if you're feeling adventurous, you can assemble them yourself. Usually this only applies to the larger models though. The advantages are that you can specify exactly what goes into the box, so if you want something with an unusual specification this might be the only option. Sometimes it works out cheaper than a ready built, but that's rare, if cost saving is the main reason, then I suggest you think twice. Anyway, here's an article on the subject:> Building your dream notebook @ tomshardware.com
What do the various options mean, and what's best?
Processor/Chipset - The processor, also known as the CPU, is probably the most important part of your computer. In my opinion the best current solution is the Intel Core2Duo. Although the Core2Duo clock speed is relatively slow compared to the Pentium4/D it's a more efficient design, so the actual performance of the chip is usually faster despite having a slower clock speed (GHz number)! The "Duo" in the name means that the processor has what are known as dual cores - basically that means two interconnected CPUs in one package. Dual core has the advantage that it adds responsiveness to the system - if you're doing something that bogs down one core, you can still use the other core to update the display and other background tasks.
Currently Core2Duo laptop processors (Merom core) have model numbers starting in "T". In case you're wondering what the difference between the T5000 and T7000 ranges are - T5000 series parts have 2Mb cache, and most T7000 series parts have 4Mb cache. More cache will generally give better performance at the same clock speed- but how much better depends on exactly what you're using the laptop for. Note: There are other Core2Duo processors designed for desktop or server use, so if you're getting Core2 make sure it's a laptop rather than desktop part! The latest platform "Santa Rosa" comes with a different processor socket "Socket P" and new chipset i965. Santa Rosa based machines should offer better Vista performance, and better battery life too.
As you may have gathered, my preferred laptop processor is currently the Intel Core2Duo. Unfortunately with their most recent processors Intel have introduced a confusing scheme of introduced model numbers. In general, the higher the model number, the faster the processor. For more information on the slightly cryptic model number scheme I suggest you have a look at the:> Intel Processor Number page @ intel.com
AMD: The main mobile challenger from AMD is the Turion64 x2. Unfortunately it's often slower and more battery hungry than the Core2Duo - but it is cheaper. Turion64 x2 parts are dual core. The easiest thing to remember is that dual core parts start with T, and single core parts start with M - higher numbers denote higher performance within that range. In other words a TL-60 is faster than a TL-40. If you're curious about the Turion model numbers there's a small explanation on the AMD site:> Turion 64 X2 Model Numbers @ amdcompare.com
A few laptops, particularly the UMPCs use VIA processors. Unfortunately whilst VIA CPUs have some nice features, small size and low power consumption being the two main advantages, they're usually by far the slowest as well...
Desktop CPU's. A few of the cheapest laptops use desktop processors like the AMD Athlon and Intel Pentium 4 - whilst they're cheap and fast, they're very power hungry, so battery life will generally be terrible, and the machine is likely to run hot, possibly uncomfortably so. Avoid.
3D graphics: Vista is the important keyword here. If you're planning to use Vista at some point in the future, remember that it requires more in terms of 3D performance than any previous version of Windows.
There are two main types of graphics - integrated, or discrete. For best 3D performance choose a discrete solution, like a Mobility Radeon or GeForce FX Go - higher model numbers generally indicate better performance within the model range.
Most integrated graphics solutions are shared memory designs, which are fine for 2D work but usually offer limited 3D performance. Shared memory takes away some of your system memory - for example a shared memory subsystem using 128Mb RAM on a 512Mb laptop will only leave 384Mb available for programs, and 384Mb is not really enough for Windows XP or Vista.
Screens are very important on a laptop, as they aren't really upgradeable. All current laptops now use active matrix (TFT) LCD screens. With some of the more expensive laptops LED backlights are starting to become mainstream, the advantages are they're slimmer/lighter, should last longer and use less power than conventional CCFL backlights.
Screen size will usually depend on the size of your laptop - some desktop replacement models have 17"+ displays, whilst UMPCs may be 8" or less. Check that you can work comfortably at the native resolution of your screen, some 15" panels run at 1600x1200 which is only really ideal for people with excellent eyesight - most people would find 1024x768 (or even 800x600) more comfortable - however on a panel designed for 1600x1200 those resolutions will appear blurry and blocky. For more detailed information have a look at the LCD display section of the FAQ here, pay particular attention to the information about void pixels!
Hard disks: Absolute minimum for a modern laptop is around 40Gb, some are now available with drives over 200Gb in size. Generally the higher the capacity of the drive the better. Spin speed (RPM) and cache size are factors though, particularly in the high performance sector - higher spin speeds are generally faster (7200RPM being the current fastest for a laptop), and larger cache size is normally better too - 16Mb is the current maximum.
Note: Solid state drives are starting to replace hard disks at the very portable end of the market, usually these drives are quite small - between 16Gb and 32Gb in capacity at the moment. Key advantages: Lower power, shock resistant. Disadvantages: Expensive, may have limited write/erase lifetimes.
There are also hybrid drives becoming available gradually, they're mainly hard disk based, but they have a certain amount of flash memory on board to cache frequently accessed files. This should mean better battery life, and longer working life. Products include the Seagate Momentus PSD range.
RAM: 1Gb is a good minimum (do not get a machine with less than 512Mb), and if you're using memory intensive applications consider getting at least 2Gb - some laptops now support 4Gb+. Remember that to access all 4Gb you'll need a 64bit processor, and a 64-bit operating system.
Battery: All new laptops use a Lithium-Ion rechargeable battery, the higher the capacity the better, although higher capacity batteries are often larger. If you're buying a used laptop check the battery holds charge - even in some one year old machines the battery can be failing, they're expensive to replace, most are between 50-100GBP (~90-180USD)
Pointing devices: There are two main types of pointing devices available at the moment, trackpoint (aka stick thing, wobble bobble, little red nubble) which is my preference and the the trackpad (aka glide point) which is basically a small pressure sensitive rectangle. This is more a matter of personal preference than anything else. I stongly suggest you try them both before you buy. Some laptops have a touchscreen display, this is particularly common in the UMPC sector.
Removable storage: CD/DVD/Floppy. Don't assume that the laptop has any or all of these built-in. Smaller machines don't tend to have any of these built-in, and may come with one external device... Most machines now have DVD writing capabilities, even some ultra-portables! Some laptops, usually the larger models, support interchangeable bays - so if you wish to you can replace the DVD-ROM with an extra battery you can. Floppy drives are very rare in modern machines, so if having one is important to you this may be the determining factor.
The next generation of removable storage is just starting to appear in laptops now - Blu-Ray (BD-ROM) and HD-DVD, although currently you'll pay a rather heavy price premium for them.
Interfaces: The latest laptops are shipping with ExpressCard slots, these come in two widths 34mm and 54mm, but are electronically identical. Ideally get a machine with 54mm slots as you can fit both sizes of card into it. With cheaper laptops there is usually at least one (type II) PC card slot (formerly PCMCIA), if there are two check that they are aligned vertically so you can use a type III card if the need arises. If you are interested in video it may be worth chosing a laptop with a Firewire (i-Link, IEEE1394, DV) connector on board (almost all Sony laptops have them). Check that the machine has a number of USB2 ports, this can then be used for Mice/Keyboards/Parallel/Serial and many other uses. Some laptops have built-in modems and/or network cards, choose whichever you think is most likely to be useful to you.
Keyboards: Unless you intend to use the laptop solely with an external keyboard check that you can type well on the keyboard of your shortlisted models. Keyboard size and quality can vary tremendously between different manufacturers, some sub-miniature laptops have very small keys which can make typing difficult. Some of the current ultraportables don't have a keyboard at all!
Software: Most machines will come with an operating system, most likely Windows XP or Windows Vista. I'm running Vista without any major problems, but if you're not a computer person, then I suggest you wait until Service Pack 1 arrives before taking the plunge - not least so that everyone will be trained and ready to support you. There are two main editions of XP, Home and Professional, which you need will depend on your usage (see: Which version of XP @ microsoft.com). There are rather more versions of Vista. The good news is that if you choose the wrong version of Vista, you can upgrade - the bad news is, it'll cost you ;) Sometimes the manufacturer will "throw-in" some additional software, decide if you would find the software useful before allowing this to influence your decision in any way. Most computers do not come with MS Office, so don't forget to factor that into your buying process too!
Some of the most interesting laptops are only released in Japan, which is frustrating, however there are companies that specialise in importing and converting these machines. An example of which is:> www.dynamism.com
For some more general reviews I suggest you have a look at:> Notebook reviews @ cnet.com
For end-user opinions, I suggest you have a look at:> Core2 Duo laptops @ epinions.com
At the end of the day, ergonomics can make or break a laptop, so I really suggest you try the machine before you buy...
- Back to the top of the page -
There are three main types of camcorder available today, MiniDV, HDD and DVD. They all have advantages and disadvantages. MiniDV can typically record for 60mins per tape. By contrast DVD can only record 20-30mins per disc at similar quality. Both can be edited digitally, although DVD has the key advantage that the discs can be played back in many standard DVD. Hard disk based (HDD - not to be confused with HD, high definition) camcorders usually have a non-removable hard disk. Check the maximum storage capacity, particularly if the hard disk is non-removable, you don't want to carry a camera on a long trip, and find you can only use it for an hour ;)
Some camcorders record to memory card instead - and quality is variable, depending on the codec and bitrate used. Generally speaking, since they have far less storage available, the quality is lower too.
HD - Allows you to record "high definition" video, i.e video with a higher resolution than PAL/NTSC - although you should check the manufacturer's definition of the term carefully, as the term can have different interpretations. More on that High-definition video @ wikipedia.org
PAL/NTSC/SECAM - Are display standards, you need to make sure that your equipment is the same standard. See: The television section.
Firewire/iLink/IEEE1394/DV - Most digital camcorders support digital I/O which means that you can edit without any loss of quality. Look for both in and out - for tax reasons DVin is often disabled on European models. If you're planning on doing some editing on your PC you need both in and out.
AV in/out - If you're planning on connecting to a TV you'll need some sort of analog connection, most camcorders offer analog out, but if you're planning on transferring analog video to your camcorder you'll need AV in as well.
S-video in/out - Offers better image quality than AV in/out, so if your other devices support it this is better than AV in/out.
RF out - This means that you can connect to any TV using the same standards. Useful if you have an older TV set without any AV inputs.
Optical zoom - This allows you to zoom in on a subject without losing (much) image quality. See: The lenses section of the FAQ.
Digital zoom - Use as a last resort. Allows you to zoom in on a subject but you lose image quality - small amounts shouldn't affect image quality too much, with larger ranges image quality will suffer badly.
3CCD - Uses seperate image sensors to record each colour R/G/B, should result in better quality images.
LCD screen - Gives you a larger colour display to shoot with, advantages - ideal for playing back scenes and collaboration, disadvantage - can be very hard to see in strong sunlight.
Image stabilizer - ideal for reducing shake on longer shots, there are two types optical and digital - optical is preferred.
Digital still - Means that the camcorder can take photographs as well as moving images, some use the video tape - others use seperate memory cards. The results are usually worse than pictures taken with even cheap digital still cameras.
Battery type - Important to choose a good running time. More info on camcorders can be found here:
There are some good shortlists here:
> Best list 2006 @ Camcorderinfo.com
There's also a good FAQ on digital camcorders and NLE (non-linear editing) here:
> Digital Video topics @ Cspry.co.uk
- Back to the top of the page -
There are two main types of consumer scanner, flatbed and film. Flatbed scanners are designed to read in documents and often photographic prints, film scanners negatives and slides. Some flatbed scanners can also scan film however. So, what are the important things to look for in a scanner?
Resolution (measured in DPI - dots per inch) gives you an idea of the finest object the scanner can see. Note, things aren't always what they seem - there are two types of resolution Optical and Interpolated. Optical resolution is the maximum amount of detail the scanner can actually resolve, interpolated resolution attempts to "guess" what's between the dots! As you can imagine of the two the optical resolution is the more important. Another thing to watch for is wildly mismatched horizontal and vertical resolutions - say 300x2400, unless you really want everything to look stretched the lower number is the more important - in that example 300.
For most document scanning uses 300dpi is ample, the only time you need higher is if you're planning on using a transparency adapter to scan film with it.
If you're looking at a film scanner then 4000dpi is probably the highest useful resolution - above that and you'll be scanning a lot of grain, but not much actual image data.
There are two common sensor types in use on flatbed scanners these days, CCD (charge coupled device) and CIS (contact image sensors). Usually a CCD based scanner will provide better resolution, but CIS is cheaper to manufacture - so CIS is usually a feature of low end flatbed scanners.
Density, usually quoted as the "D" value determines the range of shadow and highlight that the scanner can resolve - the higher the value the better in general. If this isn't listed in the specifications perhaps the manufacturer has something to hide...
The human eye can perceive roughly 16.7 million colours (i.e 24bits of colour information - 8 per channel), so look for at least that. Many scanners can scan to greater colour depths, but unless you're planning to do a lot of colour/contrast adjust in Photoshop 24bit is probably sufficient.
Scanners can throw a lot of data around - for example a high res slide scan can result in upwards of 100Mb of data, this has to get into your computer somehow... For consumer flatbed scanners the most common interface is now USB, which is relatively common on PCs and Macs these days - however USB 1.1 isn't very quick, so it's been superceded by USB 2.0 - if your computer doesn't support USB 2.0 you'll need an adapter card to get the full speed advantage, they start at around 20USD. Older high-end scanners used SCSI, but today's high end models tend to use Firewire (aka iLink/IEEE1394) - both USB 2.0 and Firewire cards are relatively inexpensive for the PC so you shouldn't be put off by them unless you're on a very tight budget, or are using a system which cannot be upgraded.
If you're looking to scan a lot of typewritten documents then you should make sure that the scanner comes bundled with a current OCR (optical character recognition) package. Some scanners also come with various image processing packages, if you're very lucky you might get a copy of Photoshop.
> Film scanners @ imaging-resource.com (up to 2001)
Scanning is a memory hungry activity, and editing those images is more so - so make sure your computer has ample RAM. RAM is cheap these days, so install some more if you can - it will often speed things up.
- Back to the top of the page -
Many people choose LCD displays for their main monitors these days - there are a number of reasons for this. The most important are that they take up less space, use less power, and they emit less radiation. Here's a list of things to look for, and descriptions of what the terms actually mean:
Display size: This is the actual visible size of the display measured across a diagonal - this size is usually measured in inches. According to most manufacturers a 15" LCD is equivalent to a 17" CRT in viewable area. Prices have come down significantly over the past year, and 19" is probably the sweet spot now.
Number of pixels/resolution: Unlike a CRT based display an LCD display is actually made up from individual pixels - this is called the native resolution (usually 1280x1024 for 17" panels) - you must run at this resolution for the image displayed to appear sharp. Some panels are better than others for displaying other resolutions, but I would recommend you only use the native resolution. Remember that screen modes other than the native resolution will appear blocky or out of focus, so it's vital that you choose a resolution/size that works well for you! There are terms for common resolutions that might prove handy:
|Name:||Res (h * v):|
Note: The resolutions listed above are fairly constant, although I'd always check the manufacturer's website to make sure that they use the same definition. For example QVGA can mean quad-VGA (1280x960) or quarter-VGA (320x240).
Technology: Modern LCD displays are TFT (thin film transistor aka active matrix), there are a number of different variations though - which is best for you depends on what you're planning to use the display for. For more information about the different types out there, check the wikipedia article:> TFT LCD variants @ wikipedia.org
True colour: Check that the display supports it, usually defined as 24bit (16.7 million colours). Anything less and areas of images which should be smooth may show visible steps. Beware: Some displays are advertised as being able to display "16.2 million colours" this is flexing the truth slightly - actually they're usually capable of 18bit (262,144) and use a form of dithering to "recreate" the other colours, do not use this type of display for image editing or colour critical work. Some older displays may offer fewer colours, unless you have a specific reason for buying one I would avoid them.
Connection type: An LCD display is digital, so ideally you should connect it to a digital signal source - that means using a DVI connector if present (or ideally buying a graphics card with a DVI connector if your current card doesn't have one). You can use a VGA-style connector with most displays, but the image quality isn't going to be as good. DVI has maximum resolution limitations - not normally a problem, but some displays (like the IBM T220) require multiple DVI connections to work. Remember to check which connectors a display has before you buy it!
Response time: Usually quoted in ms (milliseconds) - lower is generally better, most modern TFT LCD displays are fine for normal daily use. Games and fast moving images require a low number here. If you're interested in fast moving images it's a good idea to test how well the screen can display them before you buy - this is one of the few areas where older CRT type displays can be a better choice.
Contrast ratio: is the ratio of intensity between the brightest point on the display and the darkest. Higher is generally better.
Brightness: Sometimes referred to as Luminance, this is the maximum intensity of the display - usually measured in cd/m². Higher is generally better.
Viewing angle: This usually refers to the angle (in degrees) through which the contrast ratio remains accurate. Higher is better - particularly if you have a large display, or want other people to see what's on screen.
Backlight: Most displays use CCFLs to backlight, but in some laptop and high end LCD displays LEDs are now used. The LED backlights should last longer, are thinner and more energy efficient - currently they cost more though.
HD: As increasing amounts of High Definition TV/video become available, HDTV capability is increasingly important in LCD displays. The copy protection subsystem HDCP may be required to display video in high quality going forward. Also look out for HDMI ports.
IMPORTANT: Stuck pixels: (dead pixels, void pixels). Many panels are imperfect - making them is difficult, and if any dust etc gets into the display during manufacture then due to the nature of the technology there will be stuck pixels. They manifest as either bright spots or dark spots. Check the display carefully with a whole page of Red Green Blue Black and White, ideally before you leave the store - each colour should be uniform with no spots. If you can't check before you buy, specify "no stuck pixels" as a condition of purchase. Why? Well as I mentioned making a flawless display is hard, so most manufacturers have "acceptable" limits as to how many stuck pixels a panel has before they'll take it back. Stuck pixels are particularly noticable on a moving image. For more information about this issue check out:> Penalty: An Autopsy of Dead Pixels @ tomshardware.com
Reviews:> TFT displays @ epinions.com
- Back to the top of the page -
When buying binoculars the most important piece of information is the "n x nn" number. So what do these numbers actually mean? The first number is the magnification factor, and the second number is the size of the front lens in millimeters - so for example a pair of binoculars with a 10 x 40 rating magnify everything by 10x, but what's the use of the second number? Well, the size of the front lens determines how much light enters the binoculars - this is very important in low light conditions - a larger number means more light gets in, but it also means that the binoculars are bigger and bulkier!
However increasing the size of the front element is only useful up to a point. To find out at what point it stops being useful you need to consider the exit pupil of the binocular, which can be calculated by dividing the front element diameter by the the magnification factor - in the example 40/10 = 4. This number should be the same as the maximum pupil opening of your eye - for a young person this might be 7mm, for older people it could be 5mm or less.
Another thing that can significantly determine brightness is the use of coatings on the surface of the lens - an uncoated lens can lose 5% of the light available to it in reflections (compared to less than 0.5% for a multicoated lens), and there can be up to 16 lenses in a pair of binoculars - some of the best binoculars transmit over 96% of the light available! Of the options available "fully multi-coated" is best.
Something that people often overlook is the close focussing ability of the binoculars - particularly useful if you're planning to look at butterflies as well as birds. Lower numbers are better.
As magnification increases the effects of your body shake will become more apparent - to reduce this some manufacturers have added optical image stabilization to their top end products, it's useful but expensive technology... Sometimes increasing the field of view will reduce the appearance of shake somewhat, but that usually requires a larger front lens (for a specific magnification), so you trade-off weight against field of view - for reference: Field of view is either measured in degrees or as number of metres (or feet) width visible at 1000 metres (or yards), obviously this is dependant on the magnification of the binoculars...
Another option for reducing shake is to put the binoculars on a monopod or a tripod - if you're planning to do this, make sure that they have a tripod mount!
If you need to wear glasses there is one final thing you need to consider - eye relief. Eye relief is the distance (in mm) that the image is sharp for beyond the eyepiece. A value of at least 10 is desirable - otherwise you may never achieve proper focus whilst wearing glasses.For more information and reviews I suggest you read:
> Birding Optics @ birdwatching.com
There's also a nice detailed FAQ on the subject here:
> FAQ @ Optics4birding.com
High end binoculars are reviewed here:
> High-end comparison @ allaboutoptics.com
Finally check out the end-user reviews at:
> Binoculars reviewed @ Epinions.com
Support this site! If you're planning to buy anything from Amazon, please buy through one of my links. It shouldn't cost you a penny, but it should get me a small referral fee!
Click here to buy Amazon.co.uk Giftcards | Click here to buy Amazon.com Giftcards