Although a decent resolution is necessary, investing just on resolution does not necessarily make sense. When 2-3 MPixel camera is sufficient for most of us, I have seen people put hundreds of dollars into getting a 6.3 MPixel one.
There are two places where higher resolution comes in handy:
Printing : When you are going to develop your photos to huge prints, higher resolutions come in handy. But ask yourself, how many times are you going to print larger than 5x10? To help you make a decision, here is a table of Resolution to printable size table:
- Digital Camera Resolution ChartCapture ResolutionVideo Display*Print Size***2x3"4x5"/4x6"5x7"8x10"11x14"16x20"320x240AcceptableGoodAcceptablePoorPoorPoorPoor640x480 -
0.3 MegapixelGoodExcellentGoodPoorPoorPoorPoor800x600ExcellentPhoto QualityVery GoodAcceptablePoorPoorPoor1024x768ExcellentPhoto QualityExcellentGoodAcceptablePoorPoor1280x960 -
1 MegapixelExcellentPhoto QualityPhoto QualityVery GoodGoodPoorPoor1536x1180Excellent**Photo QualityPhoto QualityExcellentVery GoodAcceptablepoor1600x1200 -
2 MegapixelExcellent**Photo QualityPhoto QualityPhoto QualityVery GoodAcceptableAcceptable2048x1536 -
3 MegapixelExcellent**Photo QualityPhoto QualityPhoto QualityExcellentGoodAcceptable2240x1680 -
4 MegapixelExcellent**Photo QualityPhoto QualityPhoto QualityPhoto QualityVery GoodGood2560x1920 -
5 MegapixelExcellent**Photo QualityPhoto QualityPhoto QualityPhoto QualityExcellentVery Good3032x2008 -
6 MegapixelExcellent**Photo QualityPhoto QualityPhoto QualityPhoto QualityPhoto QualityExcellent
- Cropping: When you have not enough optical zoom to zero into the subject, or you want to take a photo which is not of regular size (like panoramic ones), you might want to take the photo and later crop (delete portions of it from borders) the photo on a computer. From my experience, after the first few months of buying the DigiCam, you won't have time to do cropping most of the time. For long distance photography, it's better to invest on a camera with good optical zoom. For Panoramic photographs, there are digital cameras (at least Canon has this feature) which allows you to take wide panoramas in stitch-assist modes (each shot is aligned to the next shot on the screen).
- Optical Zoom:
A lot of lower end digital cameras claim significant digital zoom. Some of them increment the zoom factor by multiplying Digital and Optical zooms ( i.e. a camera with 3x optical and 4x digital zooms claims to have 4X2=8x total zoom!!). It is better to discount the digital zoom part totally, as, it is effectively extrapolating your pixels (and losing details in the process). To do digital zoom, your photo editing computer will be much more effective than your camera. It's better to invest in a camera with good optical zoom that other bells and whistles.
- Shutter Delay:
A regular film camera operates in the following mode: when you press the shutter, the barrier between the outside world and the film gets removed for a brief period of time, allowing the chemicals on the film to react to the external light, thus capturing a 'photo' of it. On the other hand, a digital camera has a sensor plate (CCD or CMOS) in place of the film. As soon as the shutter is pressed, the barrier gets removed in the same manner as the film camera for a minute amount of time. But, instead of chemicals reacting to light (which can happen all over the film simultaneously), a processor starts reading the info from the sensor plate. This, depending on the capabilities of the camera, can take a significant time, causing a shutter lag (delay between pressing the shutter and capturing the photo). Research the shutter lag of the camera you are planning to buy before committing on it.
- Night Shot:
You'll have one of the major set-backs while shooting at lowlight with a digital camera. In case of a film camera, the shots taken at lowlight can be dim, but they will always be smooth. Whereas for digital cameras, the image taken at lowlight will not be smooth but significantly grainy, giving it that ghostly look. Do a little research on the nightshot capabilities of the camera you are going to buy. Another major disadvantage of digital cameras is significant red-eye. This phenomenon is present in the film cameras too. But digital cameras, being smaller and smaller, the distance between the lense and the flash has reduced, enhancing the red-eye problem.
- Battery Type:
This is of not much concern if you are buying and using the camera in the same geographical region. But if you are buying the camera, say in USA, and sending it to, say India for your kid brother, you might take the battery type used by the camera into consideration. A replacement of the proprietary rechargeable batteries used in the compact digital cameras may not be available everywhere.
Also, you might want to consider buying a spare battery for you. Going on a long camping trip, you don't want to run out of bettery. If you go for long trips to back-country, away from civilization (meaning BestBuy, CircuitCity or Frys!!), you might want to consider cameras that take standard (AA/AAA) batteries.