This depends on the RH% of the plant matter being vaped, the % of compounds in that plant matter, whether it's grinder and how, and what you describe as a "hit". Low temp "hits" will produce no visible vapour.
Some people will grind and leave the resulting material rest, spread over an open surface, for 12-24hrs before vaping with it.
B
That is the biggest difference I noticed. Bud straight out of bag gave dense hits. The remnants in tray gave off less the next day. Moisture content and temp must be biggest factors.