Digital Photography

This is a guide to using and buying a Digital Camera. I have owned and used a Digital camera for more than six years starting with my first Olympus 1.3 Mega Pixel version to my current Canon EOS 300D SLR. While living in Malaysia I used to keep an active interested in the new camera market as well as teaching Digital camera courses. I have helped several people buy new cameras, and the following, lists the main difference between traditional and Digital cameras which you need to examine and understand.

1. Battery

Understanding the type of batteries a Digital camera uses is very important as the LCD screen on a Digital camera uses a lot of power. With any digital camera, it would be wise to either get a camera with a rechargeable pack or use Lithium batteries. You can also use your own rechargeable batteries but these tend to go dead more quickly than regular alkalines. So you end up doing a lot of recharging. Having two or more sets of batteries, in this case, becomes essential, especially if you intend to travel and don't have access to a battery recharger.

For example my Canon EOS 300D uses a Lithium-Ion that is rated for about 600 pictures with flash. It is the same battery as the Canon Video camera uses.

2. LCD

Digital camera with twist-tilt LCD monitor One of the best reasons for getting a Digital Camera is for the LCD screen and the instant playback. Screen vary in size from 1.8 to 2.5 inches and in quality. The most useful ones are the swivel and tilt ones found on te Canon G series. However, as mentioned previously, use the LCD sparingly, as it consumes a lot of battery power. Also note that Digital SLRs use the LCD screen only for playback, you can not use them to frame and take photos.

3. Delay when taking photos

Digital cameras have to do a lot of calculation and processing to create an image and this can limit the performance of many cameras, making them frustrating to use. Before buying a camera explore and test the following delays: :

Boot Time - how long it takes the camera to start up;
Prefocus Time - the delay from pressing the button to getting focus lock;
Shutter Time - the delay from pressing the button all the way down to the camera actually taking the picture
Recycling Time - The time for the camera to be ready again after writing to the media
The burst mode (the number of continuous shots)

Often I have seen people move the camera after pressing the button but before the camera has actually take the picture, resulting in a blurred picture. There are a number of steps that can be done to prepare for taking the picture which can speed up the last part of actually taking the picture but you can never use a compact digital camera for sports photography.

New SLR and semi-professional Digital camera now perform almost as fast as traditional camera.

4. ISO and light sensitivity

Most Digital camera allow you to change the ISO settings. Like with film photography, a similar problem results when doing low-light photography with digital - as you get "grainier" results from shooting with fast ISO films (like 1600 or 3200), you get "noisier" results from shooting in the high ISO modes of digital cameras. A camera with ISO equivalents such as 100, 200, 400, 800, and 1600 will give you a lot more flexibility when it comes to shooting in poor light.

Camera that support ISO 50 give very clean images and camera that support ISO 3200 can take pictures in very low-light conditions. With Digital SLRs you can also select faster lens (lower F-Stops).

I use the ISO setting alot and I would suggest you look for a camera that allows you to easily change the ISO settings from a button instead of having to wade through menus.

5. Digital Zoom, Zoom Lens and the multiplier

Many compact digital cameras have both digital and optical zoom. The digital zoom is nothing more than a software zoom of the picture and my suggestion is to disable this function if you can, only use the optional zoom. You need at least 3x optical zoom, 28mm-105mm.

With a digital SLR you can replace the lens with different zoom lens, for example on my Canon ESO 300D I use a Tamron 18mm-200mm zoom lens. However, most digital camera have what is called a multiplier, see the chart for more details http://www.dcviews.com/lenses/Digital-SLR-lenses.htm. My 300D has a multiplier of approx 1.6, therefore my lens actually functions like a 28mm-320mm. For this reason it is often difficult to take wide-angle photos.

Another very useful feature to look for in compact Digital cameras is the macro or close-up mode that allows you to bring the camera closer to the subject, for taking pictures of insects or flowers.

6. Mega Pixels and Compression

Image adapted from the Microsoft Press book Sharing Digital Photos: The Future of Memories, by Dane M. Howard

The Mega-Pixel war is still raging, what does this all mean, and how many pixels do you actually require? Read the following article.

http://www.kenrockwell.com/tech/mpmyth.htm

The larger the number of pixels, the larger the file size - an important consideration if you are emailing them as attachments. The following chart shows sample file sizes, typical resolution and maximum print size for different pixel counts stored as high-quality JPEG files:

Pixels	File Size	Resolution	Print Size
1.2	480k	1152 x 864	4 x 6 inches
2.0	980k	1600 x 1200	5 x 7 inches
3.0	1.2M	2048 x 1536	10 x 8 inches
5.0	2.3M	2592 x 1944	11 x 14 inches

Another related factor with image size, which is selectable from the camera, is the amount of compression used to store the image. On higher end models you have the option of storing in RAW or uncompressed format, however, this requires a lot of storage space. Most cameras give you the option of selecting fine, medium or low, this is the amount of JPEG compression to apply to the image, the higher the compression the lower the image size, the lower the quality.

7. White Balance

White balance is the process of calibrating your camera so that it can correctly interpret colours under different type of lighting. Many compact Digital camera offer basic setting for daytime, fluorescent and tungten, but for maximum flexibility and accuracy, manual adjustment is needed. One easy way to set the white balance is to keep a white business card in your camera bag and set the white balance using this car. If you shoot in raw mode you can select a different white balance at the processing stage.


Correct white balance	Bluish image

8. Storage and memory

Memory and Storage selection is a big concern not only when taking photos but storing them afterwards. Normally your camera will Digital Camera Memory Guide only support one type of memory card but you can select the size and speed of the card. If you intend to use your camera on long trips so it is very important to either buy sufficent memory for your camera or have a method to off-load pictures onto an alternate storage device, such as a laptop or digital wallet. One of the nice options with a Digital camera is taking multiple photos of the same scene and then deleting them, but remeber to delete these unwanted photos. One other consideration is what are you going to do with the finished photos, if you are not going to print them then do you need to keep them all the largest format or RAW mode?

The other concern is long term storage. As Mega-Pixels rise the storage options reduce. For example, I used to be able to keep 6 months of photos on one 700Mb CD with my old Digital camera. Now, I use more than 1 CDs worth in a single shooting session. Another problem is with the reliablity of data storage. Hard disks crash, CD and DVDs scratch and CDs lose their data over time, therefore its import to keep your photos in multiple places.

9. Models and Costs

There are a staggering number of Digital camera on the market at the moment and more appearing all the time. Therefore when buying a camera you need to make a few decisions as to what your major uses will be, and where you will be using it. There is no point in buying a SLR if you mostly take pictures at parties and dinners, in this case it would be better to have a ultraportable model.

The other problem is cost, they are expensive compared to traditional camera. There is this notion that over time Digital camera pay for themselves as you don't need to buy film or process pictures, however this is not true as you may still want to process pictures and you need to storage the images somewhere!!

In my opinion Digital camera are fantastic because they provide instant feedback, no waiting for the roll of film to be finished before you see the results, you can download and review the images the same day. You can also take multiple shots of the same scene varying the settings and then delete the unwanted images. I learnt more about photography using my digital camera then I ever did with my traditional camera, as I was afraid to experiment and try different angles or settings.

I would suggest that you buy a well known brand and at least a semi-professional mode that gives you the option of going fully manual if you want to. Make sure you have at least 3x optical zoom, that the camera has good battery life, supports at least 4M Pixels, and is fast to start and quicky to take photos. Slow camera are the most frustrating aspect for people going from traditional to Digital. Finally look at the other features, such as TV out, USB, movie modes, etc and looks for modelsthat have lots of buttons instead of menus etc. Decide what is important upfront to narrow your search.

10. Useful Websites

Camera Sites

The best site on the web for a detailed, sometimes too detailed, review of all new Digital cameras.
www.dpreview.com and includes a buyers guide to help with the decisions http://www.dpreview.com/reviews/compare.asp

Its always best to read a few reviews on your potential purchses and here's another useful site
http://www.steves-digicams.com/ and http://cameras.about.com/

New buyers guide, what to look for http://www.opticsplanet.net/memory-card-digital-pictures-capacity.html and http://www.betterphoto.com/digital/buying-best-digital-cameras/01-intro.asp