Just out of curiosity, do the NTS maps specify the kind of aerial photos used or is this background information you'd get from other sources? At least the Finnish National Land Survey maps only state the year of the aerial photos used in map making.

That's what I'd suspect generally, but I finally found that map description that prompted the question and it was actually geological soil map - so I'm no longer certain that the more accurate scale refers to aerial photography (in this specific case). I only have the meta data and digitized soil information, haven't seen the printed original, which might give more clues.

Could you give a rough idea of what you mean by huge, and what kind of information from the point cloud do you need? I.e. only XYZ and intensity, which could e.g. be stored in blocked MultipointZM or also other attribute data which probably requires Point to get unique values for each separate point measurement?

Can't get at the legend at the moment, besides its in Finnish :P. The map is at the scale of 1:20000 and the legend says so. But descriptive text in the legend says that the map is based on aerial photographs and field work and the mapping (does not specify what part) was partly done at the scale of 1:10000. Maybe it's a reduction from drafts? I do have some literature on the specific kind of map, and was more interested if there is such a general concept as mapping scale as opposed to map scale in (pre-digital) cartography.