Adjusting Night Time Shutter Speed On A Dahua Camera

I’m sure the options available would also depend on the exact model.  Some have more flexibility than others. 

I believe the cameras already switch between day/night mode on their own off of ambient light conditions. Lux gets too low, IRs turn on.

We have setup a few Dahua cams to catch license plates and always have to tweak the shutter speed and other settings to do so. I do not remember actually setting a schedule, instead just configured the night profile and left everything else the same.

I just looked into this on one of our Dahua cameras (N25BB5Z) and the profile does not change when changing into day/night mode. I think the schedule tab might be your only option. A quick google search shows people having similar problems and having to use a script/utility to change profiles at certain times.

I assume you are looking to make sure the shutter speed never drops below a certain level, regardless of light levels, as the camera is adjusting the shutter speed up and down based on ambient lighting. On recent firmware revisions of many Dahua cameras, there is a manual exposure mode where you can set upper and lower bounds for shutter speed and gain control, and set a fixed iris. The settings depicted here are from a 6MP Dahua varifocal bullet running v2.622. The shutter is set to be as fast as needed when the scene is bright, but never slower than 1/90. We have experimented with the gain control and found that if you allow it to range too high you get a lot of noise in a dark scene. On the iris, we keep it fully open and as long as the shutter can go as fast as needed then you don't white out the picture on a bright day. On some of the recent Dahua PTZ's (like the SD59230U or SD49225T) the iris can also be set with a range, and for that we put in the full range, 0-100.

The right settings will vary with the camera you are using and the scene, but we have been able to improve our night images in many cases using this new range of settings.