Digital or Optical Zoom what's the difference?
Digital Camera Consumer Buying Guide
The increasing popularity of digital cameras has made it one of the
fastest growing categories in consumer electronics. With more products, features and functions
available now than ever before, shopping for a digital camera can be quite overwhelming.
Finding the right camera is important, because once you enter the digital world, you will never look back.
Where do you begin? What are the questions that you should be asking? How much should you spend?
Often, the right question is as important as the answer. With the right research and the right
questions you can confidently embark on the road to digital photography and begin exploring the
There are three main considerations in purchasing a digital camera:
A New Resolution - how much is enough?
One of the first questions you need to address is how much resolution you want.
Simply put, resolution determines the size of the picture the camera can print
without sacrificing clarity. Your resolution requirements are linked to the size
of the pictures you were planning to print, both now and in the future.
How does it work?
Unlike our traditional film cameras that expose the film to light in
order to capture the image, digital cameras use light sensitive sensors
to convert information on the image into digital code.
The more light sensors the camera has, the more detailed the print will be,
and the larger the print can be before distortion.
Digital images are made up of coloured dots called pixels. The greater the
number of individual dots of colour used to produce the image, the clearer the
image. Resolution is about these coloured dots or pixels.
The key to understanding resolution is in the Mega-pixel capacity of the camera.
The Mega-pixels refers to the number of light sensors the camera uses to create digital picture.
This is one of those times where more is better, so the greater the Mega-pixels,
the larger the print the camera is capable of producing.
Let's run some numbers to explain this concept:
A 3 Mega-pixel camera is capable of printing images up to 8x10, while a
4 Mega-pixel camera is capable of printing images up to 11x14. Now,
most people do not regularly print themselves 8X10's of their holiday snaps,
let alone 11X14's, but the size of the whole picture is only part what you need to consider.
With digital photography, one of the most valuable elements of the technology is
the ability it gives us to edit the images we have. While you may not choose to
hang 11X14 prints on your wall, digital images allow you to crop, enlarge and
capture that single priceless expression or a close up of a family member who
looked good in your holiday photo.
The greater the Mega-pixels you have, the better the quality of the edited picture you produce.
If there is a "downside" to high resolution, it is that the digital code can take up a
lot of space on your camera's memory. To accommodate this, many cameras come equipped
with several different resolution settings. This allows you the option of lowering the
resolution in order to have smaller file size and fit more images onto the memory card.
Close up and personal - choosing the right Zoom
The zoom function on a camera allows you to "zoom" in on a specific part of
the picture you are taking with having to physically move closer to it.
Digital cameras use two types of zooms, digital and optical. Understanding how
these features work will help you select the combination that it right for you.
Optical zoom behaves in the same way that traditional film cameras do, using lenses
to magnify the image. In other words, optical zoom brings you closer to the picture.
This is the preferred method of taking a close up picture, mainly because optical zoom
does not negatively impact the resolution of the image. The general standard for optical
zoom is 3X (which indicated a threefold magnification of the image). Higher optical
zoom is offered on many models, although upgrading optical zoom will influence the price.
Digital zoom, on the other hand, takes a portion of the image, crops it and expands the
pixels to magnify the image and brings the picture closer to you. One of the negatives
to the digital zoom is that it diminishes the quality of the image by making the pixels bigger.
Close ups using digital zoom can also be done after the picture is taken using an image
manipulation software package (included with most cameras).
Memory - How Does Memory Work?
A digital camera uses memory to store the digital code that make up the images. The
more memory you have available, the more pictures you can store.
There are very few cameras on the market that offer built-in memory because it is
generally quite limited. Instead, most cameras today include a type of removable
memory to store images called a memory card. Think of the memory card as a re-usable
digital film. The size of the memory card determines the capacity of the camera to store pictures.
The resolution of the camera also influences the amount of memory required. The higher
the resolution of the camera the larger the file size of the image. Most high-resolution
cameras can take pictures at a lower resolution setting, allowing you to fit more images
onto your memory card.
Memory cards are reusable. In order to keep the images you must transfer them to another
form of media to free up the camera's memory card. A popular option is to transfer them to
CD-ROM, which is an inexpensive and reliable form of removable media.
There are many different types of memory as well, including Compact Flash, Secure Digital,
Memory Stick, and XD. These various shapes and sizes operate in a similar fashion, and the
type of memory card you use is generally dictated by the type of camera you select.
While one memory card is not necessarily better than another, these types of memory are beginning
to appear in many other electronic devices so it may be in your best interest to keep things compatible.
An idea to consider is the purchase of an additional memory card, an extra one to use as backup.
Here again, more is better; and the more memory you have available, the greater the number of
pictures you can store on your memory card before it is full and needs to be downloaded to your
computer or transferred onto CD ROM and made into prints by a photolab.
The ability to store a large number of images without having to download is especially useful
if you are away on vacation.
If you prepared in advance you could have previously purchased a digital wallet.
This allows you to download your images into a 5, 10 or 20 gig portable hard drive
which fits conveniently on your belt, then delete the images on the card and continue to photograph.
While purchasing additional memory cards can be expensive, they are a worthwhile investment
because they can be used over and over again.
Demand for Power:
There is also the issue of batteries. Digital cameras use battery power, and should
the batteries deplete, the cameras will stop functioning. Granted the digital cameras
is more demanding on batteries however if prepared, you can overcome the power demands of the camera.
There are several options for power used by digital cameras.
Some cameras come with rechargeable batteries. Even those that don't can be retrofitted
with rechargeable batteries that are available as an add-on purchase for almost all cameras.
Since digital cameras are quite power hungry appliances, rechargeable batteries are generally
considered to be the most economical way to go.
Some cameras come with proprietary rechargeable batteries that offer convenience and often a
long lasting lithium ion battery. Lithium ion batteries, similar to camcorder batteries, have
little memory effect, which means that you can recharge the battery at anytime without having
to fully drain the battery.
They also offer a long lasting charge to maximize the use of your camera between charges.
The drawback to these systems is that, despite the longer life of these batteries, they can
be expensive to replace and are specific to certain camera models. If you select a camera
with a proprietary rechargeable battery it is recommended that you buy a spare to avoid losing
power at an inconvenient time (like in the middle of a vacation).
The other power option that digital cameras use is AA size batteries. Due, however, to the
previously mentioned power hungry nature of digital cameras, standard AA size alkaline batteries,
both disposable and rechargeable, only last a few hours in the camera with average use.
The best option for digital cameras is a high-output nickel metal-hydrate rechargeable system
The advantage to these cameras is that in a pinch, if your rechargeable runs out of juice,
a AA battery can do the job until you can get recharged.
Lithium disposable batteries also make excellent back-up power on the road due to
their long shelf life and reliability, so make sure you carry a set to all your important events.
Most cameras also have capabilities for AC adapters. For convenience, why waste battery
power while you transfer your images to your computer or view your images on the camera's LCD screen at home.
When it comes to accessories, it can be fun finding out which ones are compatible,
which ones are beneficial and which ones are right for you.
Memory Card Readers - Can simplify the process of transferring images to your computer
and save battery power in your camera. Rather than connecting cables from the computer
to your camera, a memory card reader is permanently attached to your computer.
Simply remove the memory card from the camera and put it in the reader and the
image files show up on your computer, just like any other drive, ready to be
Memory Card Adapters - Similar to memory card readers, memory card adapters plug into PC card slots,
and your memory card plugs into the adapter. PC card slots are found on most notebook computers and
offer an alternative to Memory Card Readers, which plug into a USB port on your computer, which may
Add-on Lenses - Some digital cameras have the capability to add on either telephoto or wide-angle
lenses to the existing lens. The telephoto lens can add 2x more optical zoom to your existing zoom,
so a current 3x optical zoom becomes 6x! A wide-angle adapter can allow you to fit more into your image.
Wide-angle add-ons are available in .5x.
Camera Bags - Most digital cameras do not come with bags, leaving you to choose a bag that
best suits your needs. Be sure to protect your investment as bags can protect your camera
not only from impact damage, but from weather elements as well, such as moisture and humidity.
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