I agree that snow is highly reflective but even with dark skies and no moon light and no ambient light the camera simply shocked me with that capture. It out preformed the DS-2CD2347G2-LuU to my surprise.
Hikvision ColorVu + 4K (DS-2CD2087G2-L)
- Thread starter ZeeCam
- Start date
sebastiantombs
Known around here
Snow makes a VERY significant contribution to that video. I have a 5442T-AS that I normally run in B&W at night because of little ambient light in the scene. I set it to color, we've had snow cover for the last two weeks, and it looks brighter than daylight with the slowest shutter speed set at 1/120. Take away the snow and it'll be back to B&W.
I agree. Once again I had less than optimal enviromental lighting. Even with the reflective snow, the amount light in the scene is very minimal. TDLR, it's a dark scene even with the white reflective snow. I'll wait for the snow to melt to do a comprehensive overview video.
And this is a picture taken with my S21 Ultra which really depicts how dark my scene is
And this is a picture taken with my S21 Ultra which really depicts how dark my scene is
Attachments
ljw2k
Known around here
If you update to the latest firmware V5.5.160 build 201103 then you won't be able to go back to the original V5.5.150_200927 or at least that's what I am experiencing at the moment.
I upgraded and downgraded twice from 5.5.160 to 5.5.150 but I have the ds-2cd2047g2-lu and no issues at all for me
I tried to downgrade and could not on the DS-2CD2087G2-LU. That was when I was thinking new firmware stole the gain control
Many thanks for replying wittaj. If you take the effects of noise reduction out of the argument, are you able to provide a technical explanation please? I just don’t see how ghosting can occur as a result of even the highest gain setting, or that shutter speed is a factor that we all normally associate with motion blur.
cool... with the day/night switch set to auto I got:
<Gain xmlns="" version="2.0">
<GainLevel>100</GainLevel>
</Gain>
with the camera day/night switch set to night and gain set to 75 I got:
<Gain xmlns="" version="2.0">
<GainLevel>75</GainLevel>
</Gain>
ljw2k
Known around here
Still puzzled why you can not downgrade 
Here is the original firmware DS-2CD2087G2-L(U) | ColorVu Series | Network Cameras | Hikvision | Hikvision
Here is the original firmware DS-2CD2087G2-L(U) | ColorVu Series | Network Cameras | Hikvision | Hikvision
By itself gain isn't the sole reason for ghosting, but a camera could be adjusting the NR with a higher gain. This thread below says it best and explaining how the various parameters all contribute to it. As we saw in @ljw2k example video several posts up that even at the highest gains, he has enough light that the ghosting isn't there because he is able to run a faster shutter and lower noise.
In laymen terms, I think it is easiest to say that most of us set our parameters based on what we see on a static image and we inherently add NR and makes the static image not have the dancing noise pixels. Then we up the gain and are like "cool now it is even brighter" but we see more noise, so we crank it up and then it is to a point that then with motion we get ghosting. A cause and effect. If you crank the gain too high and the noise too low, you can eliminate the ghost, but then it is a noisy mess and none of us would go with that either.
And then the cameras that do this automatically and you cannot control then results in the horrible motion videos we see. Some worse than others. My Dahua PTZ doesn't show ghosting, but if I up the gain too high and it ghosts and I didn't touch NR. Some cameras may just up the NR in response to a higher gain...or maybe the ghosting was present at a lower gain, but the gain amplified it??
Common issues with camera image
Here is a quick guide to what might go wrong with the image of your cctv camera, and how to fix this. MOTION BLUR: This is probably the most common issue, new camera owners run into. Many times on this forum I've seen posts like: "I bought a set of cameras recently. The image looks great on...
Last edited:
As promised 1/120 Exposure With 80% Gain Hik Vs 1/125 Exposure 80% Gain Dahua. Neither gets a thumbs up from me yet, but it's on the edge .
.wittaj, many thanks once again for taking the time to correspond. Although I was seeking a technical explanation and not layman’s terms, it looks like your reply and the link verifies my opening words on this topic - gain does not cause ghosting, it‘s exclusively noise reduction. Shall we leave it at that.By itself gain isn't the sole reason for ghosting. This thread below says it best and explaining how the various parameters all contribute to it. As we saw in @ljw2k example video several posts up that even at the highest gains, he has enough light that the ghosting isn't there because he is able to run a faster shutter and lower noise.
In laymen terms, I think it is easiest to say that most of us set our parameters based on what we see on a static image and we inherently add NR and makes the static image not have the dancing noise pixels. Then we up the gain and are like "cool now it is even brighter" but we see more noise, so we crank it up and then it is to a point that then with motion we get ghosting. A cause and effect. If you crank the gain too high and the noise too low, you can eliminate the ghost, but then it is a noisy mess and none of us would go with that either. And then the cameras that do this automatically and you cannot control then results in the horrible motion videos we see.
Common issues with camera image
Here is a quick guide to what might go wrong with the image of your cctv camera, and how to fix this. MOTION BLUR: This is probably the most common issue, new camera owners run into. Many times on this forum I've seen posts like: "I bought a set of cameras recently. The image looks great on...ipcamtalk.com
Cheers
Dave
Is it also possible to view the live exposure time? The exposure time we set in the web GUI is the minimum exposure time I've learned, if the light permits, he will use a better exposure time but it would be interesting to see when and if he does that.
That picture is maybe too bright, I would not use the 'low illumination' mode for moving objects. The brighter the picture, the more blur, noise, etc.. you will introduce. I think that's what everyone is doing at the moment with these cam's, finding the balance between a clear picture and a focused picture, if possible, all depending on the environment.
alastairstevenson
Staff member
To be honest - I don't know.
I suspect it's reporting the setting as opposed to the actual value the DSP is using.
I wanted to see how bright I could actually make the video in a totally dark setting. I was just conducting a quick first test after I had literally just installed the camera. I have been fine turning it over the last several days and have gotten better captures.
CCTVCam
Known around here
- Sep 25, 2017
- 2,815
- 3,683
My understanding is roughly the above but slightly different.
A sensor records the image as an electronic signal, in other words a photon of light striking the sensor induces an electric field in the sensor which the image processor then turns into a visible picture based on the electronic signal supplied. As Wittaj says, in addition to photons of light producing an electronic signal, you have "noise" which is transient current induced in the sensor by nearby electronic components. These are small electric signals that are much smaller in amplitude than eg the signal from a photon striking the sensor in daylight. As the amount of light reduces, so does the strength of the photon striking the sensor and so the amplitude of the electric current produced is smaller too. There becomes a point in low light where the signal from the photon striking the sensor becomes too weak for the processor to process, so the picture becomes black. In order to get around this or enhance a weak signal, the unit amplifies the signal it receives to make it strong enough to process. This is called the gain. However, the amplification process cannot distinguish between the actual signal and the electronic tranisent signals induced by nearby electric components as a weak signal in low light can have an ampitude not disimilar to that from the background noise of these transients. As a result, both get amplified and processed resulting in rogue pixels as the processor can't distinguish the genuine signal from the amplified background noise due oto their similar amplitude. These rogue pixels are seen in the picture as artefacts because they don't match the colour or shape of nearby pixels and so stand out as "snow". Now I don't completely understand the mechanism of ghosting but at a guess, I'd guess what is happening is the signal of the person who's moving in the picture is so weak due to their movement that the signal is intermittently too weak to be processed. As a result the person has missing pixels where the camera can't process the signal so these appear black. As these change from frame to frame, with pixels in some and not others at certain places in the image, the image takes on a transparent appearance as one frame the pixel is there and the next it's gone, then back etc. As a "video" image is a series of frames per second at a fast rate, if certain frames are missing, the object may adopt a less than solid look. I'm pleased to be corrected if anyone can offer a more accurate explanation.
I believe therefore the antidote to ghosting is to reduce the gain and if the subject can't be seen add more light. Again I defer to those with more experience if they have other successful solutions.
@CCTVCam - very well said! It is amazing how much light cameras need. The sensors are small and need light.
I suspect that ghosting is probably present even at lower gains, but they just are not registered or visibly seen until the gain is cranked up.
I have not touched noise reduction and will see ghosting just by cranking up the gain.
And we do not know the algorithms of these cameras - some or all could change the noise algorithm based on a setting and maybe because gain amplifies the noise, the algorithm automatically adjust the NR to a different scale, even if we can control the NR. So a NR at say 30 and gain at 40 may be a different NR scale for a gain at 80 and even though it may show 30 as the NR level because you didn't touch it, you probably have to crank it down as a result of the higher gain?
I suspect that ghosting is probably present even at lower gains, but they just are not registered or visibly seen until the gain is cranked up.
I have not touched noise reduction and will see ghosting just by cranking up the gain.
And we do not know the algorithms of these cameras - some or all could change the noise algorithm based on a setting and maybe because gain amplifies the noise, the algorithm automatically adjust the NR to a different scale, even if we can control the NR. So a NR at say 30 and gain at 40 may be a different NR scale for a gain at 80 and even though it may show 30 as the NR level because you didn't touch it, you probably have to crank it down as a result of the higher gain?
ljw2k
Known around here
Here is 3 clips from same time with the below settings
1st Clip 1/60th Sec Shutter & 100 Gain
View attachment 160 th 100 gain.mp4
2nd Clip 1/60th Sec Shutter & 50 Gain
View attachment 160 th 50 gain.mp4
3rd Clip 1/175 Shutter & 50 gain
View attachment 175th 50 gain.mp4
1st Clip 1/60th Sec Shutter & 100 Gain
View attachment 160 th 100 gain.mp4
2nd Clip 1/60th Sec Shutter & 50 Gain
View attachment 160 th 50 gain.mp4
3rd Clip 1/175 Shutter & 50 gain
View attachment 175th 50 gain.mp4
Last edited:
