I have a feeling I shouldn't be doing this...

[sublime]

But, whenever I have bad lighting, I just make the exposure longer. Does anyone else cheat lighting this same way, or is this simply unacceptable? Sometimes I just can't get good lighting.

Anyhow, I'll stop making excuses. My question is if there are any negatives to longer shutter speeds - so long as everything in the picture remains still - as a substitute for lighting.

If the question is absurd, please forgive me. However, you should be accustomed to me asking absurd questions by now...

[Jason Dunn]

Longer shutter speeds are the correct way to compensate for low lighting - you'll probably want to try a few different exposure times though when doing it just in case the first one isn't quite correct.

[Lee Yuan Sheng]

Well, yes, there's camera shake to worry about if the camera is not on a tripod. If the shutter speed is too low you'll get unsharp photos.