We use Photomodeler for building recording in Southampton.
We had problems with definition at first, we found we needed megabyte-hungry
digital pictures to have any detail left when we zoomed in, and you do need
to zoom in on the pc to click on your fixed points with sufficient accuracy,
or the whole thing goes squiffy in places. Then again we were using it on
buildings and photographing from 10 to 15m away.
The computer has to be calibrated for every different focal length you are
going to use so set up takes some time. Pictures need to overlap so for a
building you have to be some way away, and preferably perpendicular to the
spot you are recording.
On the plus side the dealer at Aztec was very helpful and laid on a training
course for us, the minus side was the air was blue for two weeks as we
progressed the learning curve. We still find the manual incomprehensible
(but no change there).
The good point for us was that the final 3D photos could be imported
straight into Autocad as a layer. We could trace around features, hatch them
etc on a new layer without altering the photo.
Our experience would suggest you need to take quite a lot of pictures from
all different angles to make sure you end up with a good 3D picture. We
also found that if you took more pictures from one side of a building than
another, when you produced the final view some architectural elements were
skewed slightly to the side with more pictures. While you can spot this for
a building with strong horizontal and vertical elements you would not notice
it on a layer of undulating gravel. Possibly we need more practice!
We have not tried it for plan site photography, but it does depend on easily
visible points appearing in lots of shots. I suspect you would need to have
well-marked points close to the surface you were trying to model. A 1m grid
would be ideal as you could then check that the grid had rectified. A
markedly undulating surface, or a site with lots of upstanding walls would
be very difficult without lots of clearly marked supplementary points and or
lots of photos.
For simple sites it would be quicker to plan it with pencil and film. For
complex details rectified photos would save time on site, but might be just
as time consuming in the office. I suspect that the real value of rectified
photos would be for future researchers looking for things the original
excavator might have overlooked, and more visual aspects such as museum
displays and website use.