Yes like I said these cams provide phenomenal quality in a remarkable overall package but critically offer a lot of promise and opportunity for this range and it will be great to see where they go.
Worlds First Review - Dahua DH-IPC-HDW5849H-ASE-LED / IPC-Color4K-T - 2.8mm Turret
- Thread starter Wildcat_1
- Start date
@BadKarma, FYI, I have the same "dots" in the images of all of my Color4K's. They're only really noticeable in the darker areas of my scene at night. I figured they were either hot/stuck pixels or dust and simply part of the manufacturing hiccups I'd have to settle with buying a new version of a camera. I believe @wittaj mentioned in a post I read once that sometimes you can get hot/stuck pixels to reset by holding a sheet of white paper in front of the lens for a bit. I tried that and it didn't work for me, but maybe you'll have luck trying it. If you're going to try, I recommend taping a piece of paper to the end of a broomstick instead of climbing a ladder. If it's dust I suppose you could open it up and clean it, but that's beyond what I'm willing to do. I can slightly reduce their appearance by altering my settings but by doing so I don't end up with the video quality I prefer and regardless of my settings they're always there in the dark areas. Even though I can notice them on the screen at 1X, I have to "zoom" in for them to really be apparent. Since they don't affect the evidentiary purposes I have the cameras up for they just aren't bothersome enough for me to do anything about. For reference, I've attached a screenshot of one of my Color4K's where you can see the "dots"; most easily in the dark area in the upper left of the image, but when zoomed in you'll see they're everywhere. I've also attached a screenshot of one of my Color4K's with the lens covered. I imagine if you cover yours, you'll see something similar...
Edit: I realized I should've noted that the "dots" on the vehicles are predominately old paint, dirt, and bird poop, but I do see some of the "dots" you're referring to on the vehicles as well. Also I haven't noticed them truly getting worse but I do remember kind of feeling that way for a day or two after I first noticed them, but I think that was just a trick of the mind as I was really focused on them during that timeframe. Now that some time has past, I've grown used to them and they just don't bother me. I also typically have the mindset of not letting perfection be the enemy of good enough, but your standards may differ. Of course if one of the more experienced fellows says to check something, I'd defer to them and follow their recommendations myself...
Attachments
Last edited:
BadKarma
Getting the hang of it
On a 4K monitor, it is much more noticeable. My concern is that if this problem continues to worsen after the camera's warranty has expired, I will be forced to purchase a new camera.
There is no point in spending money on a decent camera if it has manufacturing flaws; it should, in my opinion, function as intended. However, since I have other issues with my camera and mine is only a few days old, I'm going to send it back for a replacement.
Was the newer iteration a better one?
That trick for getting hot/stuck pixels to reset with the sheet of white paper was more for the cameras with infrared capabilities, so you were essentially blinding the camera with the IR bounce off the white paper and that would cause them to sometimes start working again. I have also seen that done with projectors where you send it an all white image followed with an all black image and then all white again.
I guess a similar procedure could work with a full color camera if you have the LED lights on full as the white paper comes up to it.
So I just looked back at my 4K-T images when I was testing it and trying to see how dark it could be before the image was useless.
I didn't notice before, but yes mine has some of those white dots too in the darker areas of the image.
I guess it is always possible they had a full production run of a bad batch of sensors or dust in the "pixel" screen, but it would seem unlikely.
I think it is probably some noise generated from the algorithm in dark scenes and/or some dead pixels. Maybe it could be a firmware fix to address this issue if it is indeed not dust or dead pixels.
Similar to you, I do not really see them unless I digital zoom. They certainly do not detract from the purposes of IDENTIFY a perp in the image and they can be mitigated with enough light. YMMV
It certainly isn't enough that I personally would send back, especially given the light I have.
But as I have mentioned many times with these full color type cameras (regardless of who makes them), if someone doesn't have enough light or is unwilling to run the built-in white LEDs, then they need to either go with a camera that has infrared capabilities or accept the "compromises" that come as a result of pushing the capabilities of a camera. These cameras are not magic and do need light.
I run many of my older cameras in color because I prefer color, but I recognize I am pushing it beyond the capabilities of the camera so I mitigate and minimize to the extent possible the blur, noise, etc., but I recognize there will be some based on not having enough light.
looney2ns
IPCT Contributor
I see the white dots on my 4k-t as well, fairly prominent in dark areas.
CCTVCam
Known around here
- Sep 25, 2017
- 2,831
- 3,709
Could it be they forget to remove these at the factory? As I understand it, you do get rogue pixels in a sensor but they use firmware tuning to tune the rogue pixels out of the image by telling the firmware to ignore them. That's why there's a difference in size between the actual sensor and the recorded picture eg a 4mp camera may actually have a 5mp sensor. Could be wrong and pleased to be corrected. Maybe Andy knows more on this subject.
BadKarma
Getting the hang of it
My shutter speed is 0-5ms, and it appears to be spreading around the entire screen, even where there is a lot of light. Tomorrow I'll try to cover the camera to see if that fixes the issue. My Annke nc800 makes use of a 1 1/2 sensor that doesn't produce any white dots anywhere.
Maybe I missed it in the video, but I was meaning what it looks like looking towards the camera itself at night with the LED on. Is the LED going to be annoying to everyone else in your neighborhood?
Generally you're looking at a couple of things that can cause this ('dots on screen conversations above'). I'll break down what I've seen personally in my experience across different cams and manufacturers below, and ways in which I have personally mitigated the issues if I see these. The algorithm related one is very much more prominent on full color cams based on tech being used and the AGC processing being used to bump the performance or output from full color cams at night.
HTH everyone
1 - Algorithm Related - Due to the tech employed by the algorithm itself on full color cams you do see digital elements such as the white dots on these full color cams in very dark or pitch black areas. Testing for this would be to raise exposure super high during the day and/or at night (basically creating a very dark scene), look for where the identified dots show up and see if they're static (never move on screen). If you see them 'sparkling' and / or if you see them change position on screen within the FOV, this is generally algorithm related.
MITIGATION - Can be mitigated by reducing gamma (in my experience try 35-40) when in brighter night FOV's, or by increasing light on scene in darker night FOV's and reducing gamma just slightly, say 45. The combination of both should assist along with reducing gain, try dropping 4 points so 0-45 first and see how you get on
2 - Digital Noise Related - Generally seen as crawling or pulsing, depending on where it's seen on screen may appear bright or dark
MITIGATION - Can be mitigated by increasing noise reduction (do it gradually and certainly for night would try and stay around 40) and / or reducing gamma (similar to above, I would try between 35 to 40)
3 - Dead / stuck / hot pixels on Sensor - Can occur but is usually limited by batch and if spotted (and aren't tons of them on screen) can be resolved - Generally can be identified by super high exposure during the day (again creating a dark FOV) or of course by waiting for night and again increasing exposure until dark enough to see black screen (prefer this to covering the lens) and see if you see the pixels show up AND critically if they are in the same place each time (screen grabs from each are good for a before / after).
MITIGATION - You can usually resolve these (again assuming there isn't a ton) using Pixel Mapping. @CCTVCam believe this is what you were referencing as well. Absolutely the can be done. This is generally done at a factory (if noticed on batches in production and not related to a larger issue) but can be completed with FW tuning as well. Basically the FW will look for and identify defective pixels. It then marks these and can ignore or work around them. It does all of this by calculating the data captured by other pixels surrounding defective ones. In registering these it 'tunes' or eliminates those used.
MITIGATION 2 - Another mitigation here so they are not as prominent seen is to again reduce gain BUT critically only by small amounts as you don't want to ruin your capture. Therefore in a well lit night FOV consider dropping to 0-30 but I wouldn't push down any lower than that. You can also adjust noise reduction up a little to see if that assists (again can assist in making them less prominent) but no than to 42 or so, again don't ruin your overall image
4 - Dust / Contaminants On Sensor - Will generally show as blurred areas of the optic itself and impacting the image rather than just bright white dots present on screen.
MITIGATION - Inspect the overall lens optic for opportunity to clean BUT if this is inside the sealed unit only a replacement would resolve this
With ALL of what I said above, for @BadKarma above with these 'moving around', this looks more to me like the Algorithm Related piece I mentioned above in my experience. Settings can assist here for sure in terms of mitigation. @BadKarma feel free to DM me each settings page and a) I'll mock up your settings and then b) recommend what I feel you should have yours set for and you can then retest. I can also jump on your system and dial in so we can take a look together if you wishHTH everyone
Last edited:
Well that depends on how you have them configured, they are bright for a reason but Warm in color. If you set to AUTO or MAX then of course these can go full bore brightness but you can set your manual LED brightness level to compensate for your install location. These are certainly no more impactful that a motion activated spotlight would be if thats what you're asking. If you look at the video you can see what the spill pattern looks like and based on my distance markers can see how that would play into your location. These are small but powerful LEDs' so they are certainly not going to be the big bright circles of light you see from PAR38 bulbs for example. Also remember that if you don't want to use on-camera light (I don't advocate that you do) then even adding coach lights (depending on where you're installing) or other off camera lights of your choice that you control (I advocate for this) is another option. HTH
sebastiantombs
Known around here
I'd say those LEDs, at best, are more like a powerful cell phone LED used for a flashlight, but there are two of them. I have mine set at 5% to provide fill light in a shadow area near the camera. Yes, they can be seen but they are nowhere nearly as bright as a flood light or bulb.
sebastiantombs
Known around here
In regard to the "white dots" situation. I went and examined the scene carefully and found lots of them. They appear in dark areas predominately, in my case. and some even appear and disappear as I am watching. That lead me to think it's algorithm related or setting related. I played with gamma, saturation, gain, compensation and noise reduction and got no significant results. Where I got results was improving the lighting by raising the LEDs up to about 60%. That removed almost all of the "white dots".
I'll leave it to Wildcat for the real reasons behind all this, but I think I can say it's scene lighting dependent with a fair amount of confidence.
I'll leave it to Wildcat for the real reasons behind all this, but I think I can say it's scene lighting dependent with a fair amount of confidence.
A neighbor will definitely notice it LOL. One of the many reasons why people don't use the built-in light and instead rely on other ambient lighting (in addition to the exposure issues with using it).
Think about a couple of cellphone flashlights pointed at you - the white LED is bright looking straight into them.
Here is what it looks like with the LED at 100%. Camera on the left, a flashlight in the middle, and a cellphone on the right.
And with just the camera on the left and a cellphone flashlight on the right.
Yes sounds Algorithm Related in your case as well especially if moving and if they tend to 'sparkle' when you see them.
The lighting is assisting since the algorithm isn't having to bump light artificially through Auto Iris + other adjustments (some of which expose further noise) to compensate for the darker scene.
The above is just one piece of what these cams do in the backend code, others are the way they then shift color (showed this and how to correct in my 4K-X 6mm video) in efforts to 'enhance' overall image, but this has to be done subtly as I mentioned before and had to work with Dahua to tweak so they had this correct. Dynamic contrast adjustments are also a part of the algorithm (that also was tweaked as it was too aggressive) plus things like the SW based AA filtering applied. All of the above runs the risk of adding further noise and artifacts which is why noise reduction is also tackled under the hood, separately and intelligently away from the user facing options as well. With the added benefit of brighter optics a lot of this is assisted greatly by those which means the algorithm doesn't have to be as aggressive (hence a lot of the tuning I discussed before made to the FW). This is also why the SOC is so important in the package especially for these 4K cams and is why the 4K-T is running on that edge I mentioned but the good side of that edge in providing an amazing end result.
HTH
Hahah nicely done got your hired help to assistThe neighbor's kid LOL
Thanks for your trying on this all-black scene, I talked to dahua , without any fill light, the gain will be pulled to a highest level, the problem of white DOT on the sensor side will appear, this can be handled by the software, but it will affect the clarity of the general scene. Because this all-black scene is rare, it is not recommended to modify it. So can remove the dot, but will effect the normal pic badly.
So in the nighttime when light situation is not good, the gain will increase a lot to make the pics as best as they can, this dot actually will be found on all cams, why before ones not easy to find? Because most of them use IR, black and white, why 4K easier to watch? Because it's using the 4K with 1/1.2cmos, we get the best full color pics compare to those 2mp or 4mp cameras.
So that is why daytime you will never see those dot.
@looney2ns place has very low light, so i always test low light capacity at his place, so he found the dot can explain why.
These full color cameras has big improvement compare to the old camera tech, but still need light to offer the best full color pics. And @wittaj post the light to max, most place not really need the strongest light if you are not at deep dark place, if has some light around the camera led will not even turn on.
I try to do some testing and prove the findings.
1. Warehouse is in bit low light, light even can't see the face 6ft far away, You see the left upper corner not dot, it's big white blocks,-------The camera's LED and warehouse light was shut off.
2. LED light on, so you see the left upper side, things much better change. But when we digital zoom, still find some dots nearby the light at the dark area. ------Camera LED was on.
3. I turn warehouse's light on.
Last edited:
Yes this is exactly what I mentioned here in point 1 Andy, algorithm related.
Worlds First Review - Dahua DH-IPC-HDW5849H-ASE-LED / IPC-Color4K-T - 2.8mm Turret
That's strange considering you're adjusting gain and contrast rather than focus. At least my eyes were correct in my assessment, X has the edge in day, T at night. Always good to know you're not going senile at my age! Be great to see how these evolve over time. Both very good cameras but no...
Yep, I took that picture looking back at the camera at full LED so that someone would see worse case. People tend to favor a bright image and you can certainly get that in certain fields of view with the LED on at 100.
As pointed out, all but the darkest of places wouldn't need full blast.
Mine is in a dark place on the side of the house with no light, until the field of view gets past the front of the house and gets some minimal coach light spill in the side yard at that point and I can run it at around 20 and still capture great images.
The actual "light glow" standing in the back yard looking forward is minimal. You almost cannot tell the LED is on.
But LEDs looking straight into them will appear brighter than they are.
For a backyard where there isn't a house backed up to you, the white LEDs would be fine.
On the front of the house, it would get to be a matter of the angle and what your neighbors will tolerate LOL. But if you have some coach lights on, you wouldn't need the built-in LED.
As pointed out, all but the darkest of places wouldn't need full blast.
Mine is in a dark place on the side of the house with no light, until the field of view gets past the front of the house and gets some minimal coach light spill in the side yard at that point and I can run it at around 20 and still capture great images.
The actual "light glow" standing in the back yard looking forward is minimal. You almost cannot tell the LED is on.
But LEDs looking straight into them will appear brighter than they are.
For a backyard where there isn't a house backed up to you, the white LEDs would be fine.
On the front of the house, it would get to be a matter of the angle and what your neighbors will tolerate LOL. But if you have some coach lights on, you wouldn't need the built-in LED.