Balluff MATRIX VISION mvBlueGEMINI Technical Manual page 38

e = g + h + b
h equals 0 with a single lens.
Figure 6 Setting level
The parameter h is usually not known. With lenses, normally used in combination with the
mvBlueGEMINI, h is usually very small.
For this reason, the formula without h is used in test setup concepts.
It should be possible to set every lens to infinity. In this case, the
Distance between lens and image = focal length
Therefore, each lens should be fixed in a different way. To avoid this, camera classes have fixed
distances, called flange focal distance. C-mount lenses, for example, have a flange focal distance
of 17.5 mm, which is independent from the focal length (CS-mount = 12.5 mm). With the help of
adapters, lenses with longer flange focal distances can be mounted on cameras with shorter
distances. This will not work vice versa because you will not reach infinity then.
mvBlueGEMINI Technical Manual (EN) v2.6
37
APPENDIX