cableguy2020
n3wb
I have a dumb question, but why would a 4mp cam be better than an 8mp? I'm just curios.
Thanks!
IPC-HDW3849H-AS-PV-PRO review
- Thread starter DanSan
- Start date
Thanks!
It's a tradeoff between daylight and low light capability. In daylight, I consider the 8MP to be better because it gives you clearer details and more digital zoom usefulness. In low light conditions the 4MP camera excels because its larger individual pixels capture more of the incoming light. I don't like to speak for others, but I believe that most of the forum members have decided for themselves that the increase in low light performance is more valuable than the details lost during the day.
^^^^
This
Yes, generally speaking, in daytime the 4K will provide a cleaner image, but by and large any $50 camera can provide a good daytime image.
Most of us are more concerned about nighttime image and getting good ID in low light is much much harder. Most bad things happen at night .
All things being equal, a 4MP on the same size sensor as a 4K will let in more light (bigger pixels) and perform better at night.
Now if you can light up the scene with high powered floods, and use the onboard white LEDs all night, the 4K can indeed work and produce a good image. It’s all about light.
Also as mentioned earlier in this thread, don’t be fooled by a bright colorful static image at night. The real test is a human passing in front of the camera. Bad guys rarely stop for 5 seconds to stare into the camera to assure you get a nice clean image with no movement. Once movement is introduced, you often see that bright pretty image become worthless as there is so much motion blur as to make ID impossible. We see that a lot with stickup cheap WiFi cameras.
This
Yes, generally speaking, in daytime the 4K will provide a cleaner image, but by and large any $50 camera can provide a good daytime image.
Most of us are more concerned about nighttime image and getting good ID in low light is much much harder. Most bad things happen at night .
All things being equal, a 4MP on the same size sensor as a 4K will let in more light (bigger pixels) and perform better at night.
Now if you can light up the scene with high powered floods, and use the onboard white LEDs all night, the 4K can indeed work and produce a good image. It’s all about light.
Also as mentioned earlier in this thread, don’t be fooled by a bright colorful static image at night. The real test is a human passing in front of the camera. Bad guys rarely stop for 5 seconds to stare into the camera to assure you get a nice clean image with no movement. Once movement is introduced, you often see that bright pretty image become worthless as there is so much motion blur as to make ID impossible. We see that a lot with stickup cheap WiFi cameras.
To add to the above, if you are going to be in low light conditions, it is critical to get ideal MP/sensor ratios and the 3849 and 3449 are on the same size sensor, which can also mean that the higher MP camera could potentially now be on an undersized processor.
We saw that with the previous generation demonstrating how difficult the 3849 camera is. Here is a thread of a person just a few months ago on the 3849 being burned on them.
And then these are a few of the threads made be people coming here because the 3849 camera was underwhelming.
IPC-HDW3849H-AS-PV issues
IPC-HDW3849H-AS-PV loses connection/reboots during the day
Replaced HDW5442TMP-ASE by HFW3849T1P
Dahua 8mp (TIOC): Full Colour, Active Deterrence & AI
IPC-HDW3849H-AS-PV Video Quality
The biggest problem with the previous generation 3849 camera is it was put on sensor designed for 2MP, so it needed 4 times as much light as the 2MP to produce the same brightness. And because they shoved 8MP on a sensor designed for 2MP, the sensor/cpu is undersized for 8MP.
At least they upsized the sensor in this next PRO generation, but it would still need double the light of the 4MP to produce the same image brightness. This could be the difference between the camera being able to run in color or not.
If you care about low light performance, you need a camera in green below for the MP/sensor ratio.
We saw that with the previous generation demonstrating how difficult the 3849 camera is. Here is a thread of a person just a few months ago on the 3849 being burned on them.
And then these are a few of the threads made be people coming here because the 3849 camera was underwhelming.
IPC-HDW3849H-AS-PV issues
IPC-HDW3849H-AS-PV loses connection/reboots during the day
Replaced HDW5442TMP-ASE by HFW3849T1P
Dahua 8mp (TIOC): Full Colour, Active Deterrence & AI
IPC-HDW3849H-AS-PV Video Quality
The biggest problem with the previous generation 3849 camera is it was put on sensor designed for 2MP, so it needed 4 times as much light as the 2MP to produce the same brightness. And because they shoved 8MP on a sensor designed for 2MP, the sensor/cpu is undersized for 8MP.
At least they upsized the sensor in this next PRO generation, but it would still need double the light of the 4MP to produce the same image brightness. This could be the difference between the camera being able to run in color or not.
If you care about low light performance, you need a camera in green below for the MP/sensor ratio.
cableguy2020
n3wb
cableguy2020
n3wb
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cableguy2020
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cableguy2020
n3wb
Thank you all for such detail information, newer doesn't always mean better!
another question please, lets say I have a camera with 8mpx with 1/1.8" sensor, so ideally that would be 4mpx, so the question is, if instead of making it work at 8mp cant i reduce the resolution from 8mpx to 4mpx then it would be same image quality as a camera with 4mpx with 1/1.8" sensor ?
Nope! Native resolution will always win.
Downrezing a camera does not work - It is still using the 8 million pixels - the camera doesn't change the "pixel resolution screen" on the camera when you go from 8MP to 4MP. The sensor still needs 2 times the light going from 8MP to 4MP, so the native 4MP camera will result in a better image at night. The firmware will make some algorithm attempt at downrezing it, but it could be a complete crap image or a somewhat usable image, but if there is a concern that the 8MP isn't performing or wouldn't perform well at night, then it is better to go with the 4MP.
I have a 4MP and 2MP on the same 1/2.8" sensor and the picture quality is quite different between the two and the 2MP kicks it's butt at night.
In most instances, you want to get a camera that will perform at your location for the worse situation, which for most of us is at night when it is dark and there is little to no light. If a camera performs at night, it is easier to tweak settings to make it work during the day than it is the other way around.
My 2MP cameras outperform my neighbors 4K (8MP) cameras....why....because they are both on the same size sensor.
When we had a thief come thru here and get into a lot of cars, the police couldn't use one video or photo from anyone's system but mine. Not even my other neighbors $1,300 8MP system provided useful info - the cams just didn't cut it at night.
My neighbor tried the "I will just downrez the 8MP to 2MP" and the image was a soft dark mess.
His system wasn't even a year old and after that event has started replacing cameras based on my recommendation and seeing my results. He is still shocked a 2MP camera performs better than his 4k cameras and he cannot figure out why downrezing from 8MP to 2MP doesn't work properly... It is all about the amount of light needed and getting the right camera for the right location and downrezing doesn't change the physics of the camera.
Thank you that really makes sense, as far as i can conclude from my search that currently there are no affordable ir camera 8mpx with 1/1.2" sensor, so the best current option for ir camera is a 4mpx on a 1/1.8" sensor.
or is there is something better yet still affordable withing $200-$300 ?
The best bet is the 54IR (Dahua 5442) series cameras:
EmpireTech IPC-T54IR-ZE-S3 1/1.8" CMOS 4MP IR Starlight 2.7mm–12mm Var
White color is expected to arrive in the US in 2 weeks; expedited shipping is not supported. 4-MP 1/1.8" CMOS image sensor, low luminance, and high definition image. Outputs max. 4MP (2688×1520) @25/30 fps. Built-in IR LED, and the max. illumination distance is 40 m. ROI, SVC, AI H.264/H.265...
empiretech01.com
Thank youThe best bet is the 54IR (Dahua 5442) series cameras:
EmpireTech IPC-T54IR-ZE-S3 1/1.8" CMOS 4MP IR Starlight 2.7mm–12mm Var
White color is expected to arrive in the US in 2 weeks; expedited shipping is not supported. 4-MP 1/1.8" CMOS image sensor, low luminance, and high definition image. Outputs max. 4MP (2688×1520) @25/30 fps. Built-in IR LED, and the max. illumination distance is 40 m. ROI, SVC, AI H.264/H.265...
out of curiousity how would a native 2mpx camera on 1/1.8 sensor compare to 4mpx on 1/1.8 sensor ?
Yeah. Nothing wrong with good light sensitive 2MP especially for distant target observation, but nighttime ID it's just too low res for my liking.
I use 2MP for LPR as do many and the Triple Sight is an awesome camera, but again more for observation than critical ID
The again, with enough added light, any camera can do reasonably well