30X HDCVI or 12X IP

[shdes 0]

What would resolve or produce better image at low light, a 30X optical zoom HDCVI 2mp or a 12X optical zoom IP cam 2mp? Noting IP cam being said to produce more superior image quality than HDCVI cam.

 

Just how bad is the HDCVI?

[ak357 0]

What would resolve or produce better image at low light, a 30X optical zoom HDCVI 2mp or a 12X optical zoom IP cam 2mp? Noting IP cam being said to produce more superior image quality than HDCVI cam.

 

Just how bad is the HDCVI?

U can't beat IP 2 MP 30X optical with IR

[shdes 0]

What would resolve or produce better image at low light, a 30X optical zoom HDCVI 2mp or a 12X optical zoom IP cam 2mp? Noting IP cam being said to produce more superior image quality than HDCVI cam.

 

Just how bad is the HDCVI?

U can't beat IP 2 MP 30X optical with IR

 

 

People in the past here have said HDCVI has bad image quality compared to IPs. But not sure if it is the HDCVI compression or the cmos sensor. And the tests were done using dahua manufactured CMOS. In dahua HDCVI PTZs.. they use the 1/2.8" exmor sensor instead of their own.. anyone has tried any of this? How does it perform? Is the image quality like that of IP? Or is it as bad as their own cmos.. due to HDCVI compression?.. what you think guys?

[SunnyKim 2]

Please note that there are have been three ways to send HD sized video information from camera to the place where it is being displayed and stored.

One way is to compress video information, before being fitted and transmitted over network cable. We call this IP Camera. You may need to put an equalizer(boosting & shaping up signal before re-sending) up to every 70~80 meter distance.

The 2nd type is to send video information without being compressed, over conventional cable,say RG59. The compression and display can be done at the DVR side. We call this as HD_SDI (serial digital interface: the digitally captured video data are serialized, in bit by bit & modulated before being transmitted). The problem lies in the fact that the amount of video data is huge, so carrying a very high frequency as a result. Thus HD -SDI can be limited to a cabling distance up to 100 meter. It may also need a fine tuning for the parameter settings at the receiver side (HD-SDI DVR). As HD-SDI needs a very high tech, what called SerDes, not many chip suppliers exist. Therefore, a bit high pricing.

The 3rd one can be grouped for 3 kinds, so far, HD-CVI (Daihua), HD-TVI (Hikvision and many others), and AHD (nextchip). These kinds are just adding/inserting more number of pixels to the conventional NTSC/PAL signal, not really though in fact. Thus, carrying a higher frequency component as a result, limiting the cable distance, as well. It claims 300 meters over conventional RG59. It may be true on the very high quality cable, say pure gold/copper/no cladding. But we observe the video quality getting deteriorated gradually from 30 meters on the cheap cables in our Lab. This type needs a DVR for the same kind --HD-CVI, TVI, AHD type cameras, respectively for storing video data and monitoring. But they are much cheaper than HD-SDI solution.

As thus explained, in terms of video quality, IP camera could be the worst, letting alone the price.

[shdes 0]

Please note that there are have been three ways to send HD sized video information from camera to the place where it is being displayed and stored.

One way is to compress video information, before being fitted and transmitted over network cable. We call this IP Camera. You may need to put an equalizer(boosting & shaping up signal before re-sending) up to every 70~80 meter distance.

The 2nd type is to send video information without being compressed, over conventional cable,say RG59. The compression and display can be done at the DVR side. We call this as HD_SDI (serial digital interface: the digitally captured video data are serialized, in bit by bit & modulated before being transmitted). The problem lies in the fact that the amount of video data is huge, so carrying a very high frequency as a result. Thus HD -SDI can be limited to a cabling distance up to 100 meter. It may also need a fine tuning for the parameter settings at the receiver side (HD-SDI DVR). As HD-SDI needs a very high tech, what called SerDes, not many chip suppliers exist. Therefore, a bit high pricing.

The 3rd one can be grouped for 3 kinds, so far, HD-CVI (Daihua), HD-TVI (Hikvision and many others), and AHD (nextchip). These kinds are just adding/inserting more number of pixels to the conventional NTSC/PAL signal, not really though in fact. Thus, carrying a higher frequency component as a result, limiting the cable distance, as well. It claims 300 meters over conventional RG59. It may be true on the very high quality cable, say pure gold/copper/no cladding. But we observe the video quality getting deteriorated gradually from 30 meters on the cheap cables in our Lab. This type needs a DVR for the same kind --HD-CVI, TVI, AHD type cameras, respectively for storing video data and monitoring. But they are much cheaper than HD-SDI solution.

As thus explained, in terms of video quality, IP camera could be the worst, letting alone the price.

 

Tnx.. for PTZ especially zooming.. does the lag of IP cam be more disadvantageous than the more real time HDCVI?

 

But the dahua HDCVI has bad image quality (see archives here) compared to their IP equivalent.. could it be because of the proprietary sensor they are using.. but in their PTZs.. they use the sony exmor sensors.. how does the image quality differ in them.. anyone?

[SunnyKim 2]

Lag could be an issue for IP cameras. But this could be improved if you apply proper parameter setting to your camera, if permitting. One more issue for IP cameras could be that a single bit error in compressed bit streams during transit could destroy all video data of 1~2 second duration.

As said, high data rate of hd sized video means high frequency in communication. High frequency is getting destroyed as the cable length gets longer.

The bad quality of HD-CVI could be coming from the long cable, as there are no reason for IP cameras to use a better sensor.

If the distance is short, the video quality of HD CVI could be OK, not much degradation.

[shdes 0]

Lag could be an issue for IP cameras. But this could be improved if you apply proper parameter setting to your camera, if permitting. One more issue for IP cameras could be that a single bit error in compressed bit streams during transit could destroy all video data of 1~2 second duration.

As said, high data rate of hd sized video means high frequency in communication. High frequency is getting destroyed as the cable length gets longer.

The bad quality of HD-CVI could be coming from the long cable, as there are no reason for IP cameras to use a better sensor.

If the distance is short, the video quality of HD CVI could be OK, not much degradation.

 

No. Don Stephens tested IP side by side with HDCVI using short cable. I also saw it at

the showroom. The HDCVI are more faded in colors. Don himself wrote:

 

viewtopic.php?f=53&t=40736&hilit=hdcvi+quality&start=15

 

"There's a color difference between their IP and CVI. The IP cameras appear true to color while CVI is slightly "grayed" for a lack of better word. Other than contrast, they look pretty similar."

 

"You can really only see the change in contrast on the building across the parking lot where the cameras transition. It's a dull area as far as color is concerned. It gets much more obvious when you look at brighter colors."

 

----------------

If you guys will compare IP side by side with HDCVI. the HDCVI are more faded in colors even with short length cable so it is not the cable.

 

I wonder if it is the poorer sensors dahua themselves made in their fixed lens HDCVI. However, note their PTZ zoom HDCVI uses the sony exmor lens. Anyone has tested this lens. Is the color better or still as faded as their fixed lens HDCVI?

[SunnyKim 2]

You got the point. We also observed color fading in HD-CVI. That would be the same for HD-TVI and HD-AHD Types, though we have not tested them. They probably tried to reduce high frequency before putting signals on the cable and to increase the cable length possibly. My guess is that for reducing high frequency components, they probably applied a kind of low pass filter, thus hurting contrast. They may also have allocated a bit smaller bandwidth for delivering color components. So the color quality would be a bit worse, as a result.

I tried to explain whys. But it is up to you which one to choose.

[shdes 0]

You got the point. We also observed color fading in HD-CVI. That would be the same for HD-TVI and HD-AHD Types, though we have not tested them. They probably tried to reduce high frequency before putting signals on the cable and to increase the cable length possibly. My guess is that for reducing high frequency components, they probably applied a kind of low pass filter, thus hurting contrast. They may also have allocated a bit smaller bandwidth for delivering color components. So the color quality would be a bit worse, as a result.

I tried to explain whys. But it is up to you which one to choose.

 

But we are not yet sure if it's the no-brand generic sensors dahua used in the fixed lens HDCVI. Have you also tested the PTZ Hdcvi (which uses the exmor sensor)? same color fading?

[SunnyKim 2]

I do not think Daihua uses a generic no brand sensor. They may have erased the original labelling to protect their intellectual property, just in case. Most of sensor manufacturers are chip giants, much bigger than Daihua. Daihua is trying to establish their brand name. No reason to save pennies on sensor.

We never have used PTZ_HD-CVI. PTZ is just up to motor control. No relation to image sensor or video quality.

[shdes 0]

I do not think Daihua uses a generic no brand sensor. They may have erased the original labelling to protect their intellectual property, just in case. Most of sensor manufacturers are chip giants, much bigger than Daihua. Daihua is trying to establish their brand name. No reason to save pennies on sensor.

We never have used PTZ_HD-CVI. PTZ is just up to motor control. No relation to image sensor or video quality.

 

Why have you never used PTZ_HD-CVI? You mean you only use PTZ IP based? In my country, there are only dahua PTZ HD-CVI (see http://www.dahuasecurity.com/products_category/ptz-camera-489.html). There is no PTZ IP (because these are more expensive).