Marker workflow / scale bars

[easty]

Hi. 
Context : > Ive taken a set of images ( building ) . I place 15 markers and create several scale bars that are based on several known distances from a site survey.

1 ) a couple of the markers ( survey points ) I enters X , Y Z values . Is Y up ? +Z to camera. Right now Its impossible to tell . What is the photoscan world coordinate system .

2) What is the correct workflow , do I align images first > then add markers >then realign images again ?

3) if I define some survey points X Y Z world. When exporting will that mean the point cloud is  Y up in a 3d package

4) Often I can add markers  in other images of course that point is not visible in another image.I then get what looks like a grey wisp of smoke , can they be left alone.

5) Is there a up to date workflow tutorial , as right now things seem still very fractured. I am after a video on markers / scale bars /

r

[bigben]

Z-Up
http://www.agisoft.com/pdf/PS_1.1_Tutorial%20%28IL%29%20-%20Coded%20Targes%20and%20Scale%20Bars.pdf