Resolution
Generally, a camera with 3 to 5 million megapixels can print upto A4 size. Digital cameras with 6 million pixels or more can print upto A3 or higher. Many cameras offer the facility to change the resolution if a low resolution image is required i.e. for web pages. Images are commonly saved in the JPEG (Joint Photographers Expert Group) file format which allows the digital camera or computer to compress the image to maintain quality and reduce file size.
Zoom Lens
Most point and shoot digital cameras have a 3x zoom lens which goes from semi wide angle to short telephoto & is usually the equivalent of a 35 - 105mm zoom lens on a 35mm camera. These lenses can go wide enough to shoot small groups and then zoom in for a portrait at the telephoto end. A small range of mostly high end cameras offer larger zoom ranges although Canon does provide 4x zooms on many of its budget series "A" Powershot cameras such as the A530 and A540. Digital SLR cameras have interchangeable lenses which provide the greatest choice from spectacular super wide fish eye lenses to huge telephoto lenses.
Shutter Lag
This is the time it takes to press the shutter and for the actual picture to be taken by the digital camera. Pressing and holding the shutter halfway before releasing it fully can reduce the time dramatically on most point and shoot digital cameras. Unfortunately there are still many digital cameras that can take .5 to 1 second to take a photograph. Shutter lag is virtually non-existent on digital SLR cameras and on some compacts.
Many digital cameras, especially point and shoot, offer limited control by including scene modes such as portrait, night, flower, snow, beach and many other categories. These are usually in addition to the program mode.
Flash
A small built in flash is a common feature on nearly all digital cameras and can light up a subject when lighting levels become too low. The flash range is normally 3 to 5 meters. Some prosumer and professional digital cameras have a hot shoe which allows a more powerful flashgun or studio flash to be attached.
Viewfinder
Digital cameras are dominated by four types of viewfinders:
| Optical - a small window which can feel like looking through a small tunnel. | |
| LCD. - a small TFT screen on the back of the camera ranging in size from 1.5" to 3". Many LCDs today accurately frame a picture by showing 100% of the scene. Some cameras offer both optical and LCD viewfinders. | |
| EVF - Electronic viewfinders are used on some prosumer cameras with long zooms with most showing 100% of the scene. They can suffer from a slight lag when any movement is involved. | |
| Pentaprism - most SLRs use a pentaprism or pentamirror to project an excellent and clear image to the eyepiece. |
Manual Controls
Options such as aperture priority, shutter priority and full manual control are available on higher end digital cameras and some low cost enthusiast compacts. These features allow a photographer to take control of the camera's exposure and are a great learning tool for the amateur and enthusiast. All digital SLR cameras come with manual controls for greater photographic control.
Battery Life
There are a wide range of proprietary batteries used by camera manufacturers with some cameras using the commonly available AA batteries - both alkaline and Nimh rechargeable. Proprietary batteries are often rechargeable but can be expensive. It is advisable to carry a spare battery - even for digital cameras with a long battery life of 300 shots or more.
AF Assist Lamp
This helps the digital camera to focus in low light conditions. Cameras without an AF assist lamp usually struggle to focus in low light.
Memory Cards
These come in all shapes and sizes ranging from 16mb to 4gb. Some of the most commonly used formats include compactflash, secure digital (SD), XD, memory stick & multimedia (MM). Most cameras come with small memory cards such as 16mb which only allow you to take a handful of shots before they fill up. Buying a larger card such as 256mb or higher is often necessary.
Movie Mode
Digital camera movie modes used to vary enormously but now, many cameras offer unlimited VGA movies at 30 frames per second (fps). Unfortunately even a 10 to 15 minute movie will quickly fill up a 1gb memory card. Cameras offering MPEG4 movies allow high quality movies to be more efficiently compressed. A 1gb card can record one hour of MPEG4. Digital SLR cameras do not have movie modes. Some cameras are now offering high definition video at resolutions of 1280 by 720 but these take up enormous amounts of space on memory cards.
Other features which may be of interest to some users include:
| Weatherproofing - allows cameras to be used in the rain or on the beach as they have weather proof seals. Some cameras are also waterproof upto a certain depth while camera housings can offer this facility to other cameras. | |
| Image Stabilization - this allows a user to handhold a camera (especially with a long lens) in lower light than a standard camera. Optical and CCD shift image stabilization cameras are more effective than digital stabilization which just involves raising the ISO and therefore making the pictures more prone to grain. | |
| USB - the universal serial bus is the most common way to connect a camera to a PC to download images. USB is available in versions 1.1 which runs at 12mps and version 2 which runs at 480mps. As you can see, USB2 is the preferred option as it is 40 times faster than USB1.1 and is also backwards compatible with 1.1. |
1 comment:
Keep up the good work.
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