Photography has always had the potential to be an expensive hobby or business. Cameras are precision instruments with delicate components. Modern digital compact cameras are wonders of technology, often with multiple pre-programmed modes for different scenarios and face recognition technology to help focus on the person in the frame. That's always what you want to do after all, isn't it?
As Nobby Clark confirmed during his visit in Term 1, these days it is inevitable that you shoot with digital equipment. Everyone else does. Deadlines are tighter than ever. In the commercial world you are also expected to be able to turn around jobs very quickly. Having a CD-ROM of images ready for couriering virtually by the end of the dress rehearsal.
I believe that the best kit for theatre photography is a full frame digital SLR, such as the Nikon D700 (my choice) or Canon 5D and 'fast glass'. By that I mean lenses with wide maximum apertures. For zooms this is typically f2.8. For a fixed focal length lens (50mm or 85mm say) it can be as wide as f1.4. or f1.2.
The fast glass gives you the ability to capture the maximum amount of light. This is not only good for exposure but also gives you and the auto-focus system a brighter image to work with. The full frame means that each indiviudal light sensitive cell in the camera's sensor has more space to itself which leads to less noise at higher ISO values. I will happily shoot at ISO 6400 with the D700 and get acceptable results.
Entry level digital SLR cameras have, until recently, tended to max out at around ISO 1600. With their smaller sensors, this is no bad thing as they will tend to give quite noisy results, often from ISO 800 and above. Compact cameras, with their even smaller sensors, are limited to yet lower ISO values, if you want to keep the noise levels manageable.
People sometimes ask me about camera kit that they should buy. I always try and stress to them to buy the best and fastest lens they can. Great optics can bring out the best from a mediocre camera. Poor optics can render even the most expensive body worse than mediocre. Think of good glass as an investment in the future. If you stick with the same manufacturer then you will be able to upgrade the camera body but keep using the same lenses. One of my favourite lenses is a manual focus Nikkor 85mm f2, that is now around 30 years old. it is a great portrait lens and still works today in aperture priority or manual mode on the D700.
The only other piece of kit I use on a regular basis for theatre photography is a sturdy monopod, with quick release brackets already attached to camera body and zoom lens mount. For some really dark productions I've resorted to using a tripod but this can seriously handicap freedom of movement, and getting the actors and elements at the right angle is half the battle.