just to note that hdr is not necessarily the act of producing overdone pictures.
hdr is the technique of combining several exposures within a single dataset, stop.
It is left to the user to pick a visualisation technique to display the dataset on a low dynamic range display.
most, for artistic purposes, use a colourful tone mapping.
and what is usually identified with the name of hdr is just tone mapping
you can get a very close result with a single image by using highlights and shadow enhancers, so no need of a tripod and mulyiple exposures.
you are talking about hdr (the combined dataset) for scientific purposes, then it is a more critical process as with any digital M pictures do not have an aperture exif tag (only the guessed one).
so you will need to add the aperture tag before going ahead and combining exposures.
some tools of the trade here:
to edit exifs
to combine pictures and display luminance values
some reference on the matter: