The mirror on the bottom matchbox type compass does not allow one to use the mirror for other uses. It will only fall out at the angle necessary to view the compass needle.

The mirror on the bottom compass (Recta matchbox) does indeed have a clear bottom and can be used just like a standard Ranger compass on the map...the mirror slides out when needed for sighting, but slides back into the matchbox when using it on the map.

The matchbox is a great compact compass, with its only real drawback that the mirror cannot be used for any other purpose.

There is no way I would consider a lensatic compass for most any need. Neat they are but impractical, heavy and not anywhere near as easy to use with a map as a good Ranger or standard baseplate compass is.