Questions for the expert

[dubber]

Hi All

I have a 4KT and the new MINI PTZ.

My 4KT can only be used with 1/120 or 1/60 at night. If any other shutter speed, I'll see the horizontal rolling lines.
My mini I can use it 1/75,1/90,1/100 etc and no horizontal rolling lines.

My Garage flood light is turn on a at 40% brightness. I switch it to 100%, same issue, with 4KT.

Both camera are looking at the same FOV and are side by side.

May I ask if someone could explain why one camera behave different vs the other?

Please see attached picture of my driveway for reference.

 

[wittaj]

As I mentioned previously, I think the rolling/pulsing is a byproduct of the 4K/T pushing the limits of what can be achieved in color with low light and faster shutters. They are trying to squeak as much out of it as they can since the camera doesn't see infrared.

The mini can see infrared so the firmware isn't pushing as hard to maintain color as it can go to B/W with infrared.

They are different chipsets and firmware each tailored to the strength of the camera. Same reason a chevette isn't as fast as a corvette even though they were both Chevy lol.

There is some chatter about this very topic in the 4K/T thread and some have been able to mitigate it by dropping sharpness.

Worlds First Review - Dahua DH-IPC-HDW5849H-ASE-LED / IPC-Color4K-T - 2.8mm Turret

What about if you reduce sharpening?

ipcamtalk.com

 

[CanCuba]

I put up my new LED panels last night and had rolling black bars on my Color4K/X, as well. Setting the shutter to 1/60 or 1/120 fixed it. Oddly enough, if I set the shutter to a smaller fraction of 1/120 (4.16ms which is 1/240), I still had the black bars which I found odd. Doesn't matter as the image was far too dark.

1/120 with 25 gain will have to do, I guess. Great image with excellent detail at about 35 feet with a 2.8mm lens. This is an overview cam so being able to make out clothing details including shoewear will be helpful in the future.