Ask Engadget

Alright, time for another Ask Engadget. Last week Dan wanted to know what stuff people kept on their USB keychain drives, this week reader Martha B. has a question about digital cameras:

I have a small digital camera which I love (the Pentax Optio S), but for taking nicer pictures I'm still using a regular SLR film camera. It's starting to show its age, so I've been thinking about taking the plunge and buying one of those new digital SLR cameras, and am at a loss about how to choose one. Are the cheaper ones like the Canon Digital Rebel good enough, or is it worth spending the money for a more professional camera? What else should I look for? If I buy a Nikon will I be able to use all the lenses from my old Nikon SLR?

Any advice?