LTS vs. Dahua camera comparison

[tigerwillow1]

I have a 4MP LTS CMIP9142W matrix IR (EXIR) camera that I've been not-to-thrilled with since day one. I tried a similar Dahua DH-IPC-HFW4431M-I2 camera, and wow, what a difference.

Stability: I've been fighting with the LTS configuration. If the bit rates are set too low, the image quality (to be expected) suffers. If the bit rates are set too high, the main stream disappears. No such problem with the Dahua camera. H264zip+ isn't worth using, too much image corruption sometimes with motion.

Features: Dahua has more features: Gamma adjustment, auto exposure mode, and much nicer setup for motion events. It also has several additional event types I haven't tried.

Image quality: The most important thing for me, and the Dahua camera is significantly better. Here are two crops for comparison. The cameras are side-by-side, so the images are from the same place, same time. The clearer images are the Dahua camera. The license plate is in the ROI area, the bush is outside the ROI area.



Any explanation other than the Dahua camera is just better?

 

[alastairstevenson]

The cameras are side-by-side,

What focal length are the lenses?

 

[Kawboy12R]

Hik 4mp main stream works fine at higher bitrates. Something's wrong with your install somehow. What're you using to view/record? What happens if you switch a Hik with a Dahua and use the same cables? Bitrate/bandwidth problems follow the camera or stay with the position?

 

[tigerwillow1]

What focal length are the lenses?

They're both 6 mm. The LTS camera has a slightly larger FOV. Its resolution is 2688x1520. Dahua resolution is 2560x1440, pretty close to the same aspect ratio.

 

[tigerwillow1]

Hik 4mp main stream works fine at higher bitrates. Something's wrong with your install somehow. What're you using to view/record? What happens if you switch a Hik with a Dahua and use the same cables? Bitrate/bandwidth problems follow the camera or stay with the position?

I'm recording with an LTS 8916, and viewing via the NVR or the camera's web interface. Behavior is the same either way. I have 2 LTS cameras that behave the same, for instance, right now today they work as follows:

CBR max bitrate 16,384, 10 FPS, I-frame 10, main stream is ok.
Change to 4 FPS, main stream disappears.
Change to bitrate 8,192, main stream re-appears.

When the bitrate is "too high" for the image, the main stream just stops. It depends somewhat on the image content. A more complex image will work at a higher bitrate. The main stream can disappear or reappear with changes in the image complexity. When I added the Dahua camera I put it on the cable that the LTS camera was on previously. The Dahua camera constrains to a maximum bitrate for a given FPS and I-frame interval. The LTS camera lets me set to anything I want, shows a green check mark, then cuts the main stream if it doesn't like the setting. Set the bitrate too low, lose quality. Set it too high, lose the main stream. And what works one time might not work another time (e.g. day vs. night, or bare ground vs. snow).

 

[Kawboy12R]

Seems strange but 16kbps at 4fps isn't exactly normal or needed. Sounds like you need a call to LTS anyway though.

 

[tigerwillow1]

Seems strange but 16kbps at 4fps isn't exactly normal or needed. Sounds like you need a call to LTS anyway though.

Agreed, it's just a way to isolate the issue. I've had the main stream drop at 10 FPS and 8,192 bitrate at times, it's not consistent. The only safe setting I've found is to use VBR at 8,192 or lower, with zip+ off. I'm overall pretty unhappy with all the bugs. I didn't mention the NVR bugs to keep it simple. I find myself switching between the web interface and two different PC clients because things that work on one don't work on and/or crash the others. And now that I see a different brand camera has a much better image without the bugs, I'm wanting to turn back the time machine and start over.

 

[zero-degrees]

I've never seen that much image degradation with LTS hardware - that almost looks like sub stream. I'd be curious what the full image capture looks like vs. being cropped down.

 

[tigerwillow1]

Here are a couple of full images. The biggest difference is in the tree and shrub branches, and the snow texture. That sub stream comment got my attention. I'm "assuming" I'm recording the main stream. I don't see anywhere on the NVR to select otherwise. The live views are similar to the recordings and I know for sure when they're main vs. sub stream. The LTS image falls flat when there are low contrast features. On high contrast areas, like the double yellow on the road, it does better.

 

[nayr]

looks like the dahua might have WDR on and is running at a higher shutter speed by looking at tires, definitely more detail

 

[tigerwillow1]

looks like the dahua might have WDR on and is running at a higher shutter speed by looking at tires, definitely more detail

Wow, good eye! My first thought was to make all the image/exposure settings the same on the 2 cameras, which doesn't work because the images end up looking very different. So I went to making them have a similar appearance. In the samples 2 posts above, LTS was at 1/250 shutter and Dahua was on auto. I took some new more carefully controlled snaps today to send to LTS. With new snow and sunlight, the best LTS shutter speed was 1/1000. To get a similar image on the Dahua I had to use 1/4000. The biggest challenge was trying to get the color balance the same. I think I could spend the rest of my life fiddling white balance and never get identical colors.