The subject you are inquiring about is called "latitude" or "dynamic range" -- the range of illumination which can be recorded by a sensor with some detail, between the limits of total black and total white. For B/W film or color negative film, this range is roughly 8-9 f/stops. For color positive film, this range is much more limited, perhaps around 5-6 f/stops.
Try doing a simple test for yourself -- photograph a uniform or slightly textured surface at your meter reading and also several f/stops above and below, then examine the results. If you do your own printing, print the metered exposure so that it comes out medium gray, then print the other exposures the same, letting them come out brighter and darker. You will then know what to expect when photographing a scene with high dynamic range. If you shoot digital, or if you scan your film and print digital, you can simply read the {R,G,B} or Luminance values directly from the digital files and see how they vary with exposure.
To really understand this subject, reading an Ansel Adams book on the Zone System is highly recommended.
[a href=\"index.php?act=findpost&pid=122438\"][{POST_SNAPBACK}][/a]
Also your range will be reduced when you come to scan the negatives if you don't use a quality scanner. If printing direct from the negs this is less of a problem.
Exposure will depend on your subject and what you would like to achieve. If you think the brightest parts are more important bias your exposure to capture detail in them. An example would be a setting sun with a nice cloud formation, if you don't think burning out a lot of detail would help, then stop down some, this would not be very helpfull to shadow detail though, the choice is yours at the time of shooting.
A spot meter is a big help when deciding which tones to record and which to let go.
With neg you do have a huge range, I once exposed a roll of Reala at 800iso by accident, it was still printable.
I also think scanned negative has wonderful colour.
Kevin.
