Quoting from one of my CCTV supplier's catalogues .....

Lux                                                  Description

50,000                                             Summer sunhine
5,000                                               Overcast sky
500                                                  Well lit office
300                                                  minumum for easy
reading
50                                                    passageway / outside
wkg area
15                                                    good
main-road-lighting
5                                                      typical side-road
lighting
2                                                      minimum security risk
lighting
1                                                      Twilight
.3                                                     Clear full-moon
.1                                                     typical
moonlight/cloudy sky
.001                                                 typical starlight
.0001                                               poor starlight

Bearing in mind that the minimum illumination figure can also be massaged as
well for marketing reasons,  it's not a really good way to plan a
surveillance system.              In surveillance-speak,  'minimum
illumination' is the lowest amount of light that an object of X%
reflectivity can be identified through the camera.          Obviously,  a
black or dark green object will be harder to spot in poor light than a white
one.         For the 'min illum' figure to make sense,  the reflectivity of
the test object should be listed as well,  however most camera manufacturers
won't.

It sounds like you may be looking at one of the simpler colour dome cameras
that retail for AUD$1-200 in the surveillance stores.           Can I
presume that for home use,  you want to check the outside perimeter of the
house or the identity of the person at the front door,   before you get up
to answer the doorbell ?

Depending on the size of your house and your budget,   you may want to look
into B&W cameras - only cheapies and Infra Red spotlights.            Allow
for an effective range of 3-5m per camera and about 5-10m per IR spotlight.
The resultant picture is clear as a bell B&W video,  while to the prowler
outside,  it's still as dark as the inside of a brown dog.