Michelle - Most higher end DSLRs have around a 5-6 stop usable range. I think I would put RAW images closer to print film with JPEG being closer to slide.

What I think the speaker was referring to is the whole "exposing to the right" technique that many employ - I think we had a thread about that a while ago. Just remember to watch it closely. Clip your highlights on any channel and that data is gone for good. Keep in mind that the histogram you see on most consumer level DSLRs is a composite one so, while your overall "average" histogram may look good you could be clipping the R, G or B channel and not know it.

Also, make sure if you do "expose to the right" that you do not use the compressed NEF format as it would seem that it throws away a great deal of the info that resides there for its compression.

-=>Donald