Best image settings for 8MP camera

[kmb786]

Hi

I have a 8MP bullet camera installed - model DS-2CD2685G0-IZS

I have it configured so that the footage is in colour at night with the following image settings which you can see in the attached screenshots.

As it’s a 8MP camera, I’m not sure if I’m getting the best picture quality day or night so can someone please confirm if the settings in the screenshots are ok.

I have also attached screenshot of day and night picture.

Thank you

 

[JB1970]

The main issue is that if/when you have an incident the footage is unlikely to provide a decent still image without motion blur. This is because you have the shutter speed set at 1/25sec and that's not fast enough to freeze motion of anyone at walking pace. Try it for yourself - walk through the camera image tonight and then playback the footage tomorrow and pause the image. To prevent motion blur you have to speed up the minimum shutter speed. However raising it to 1/50sec will halve the amount of light reaching the sensor making the image darker, changing it to 1/100sec will halve the light again and so on.

Also I'd lower the WDR setting unless you need it that high as this can also cause issues with moving objects.

 

[kmb786]

The main issue is that if/when you have an incident the footage is unlikely to provide a decent still image without motion blur. This is because you have the shutter speed set at 1/25sec and that's not fast enough to freeze motion of anyone at walking pace. Try it for yourself - walk through the camera image tonight and then playback the footage tomorrow and pause the image. To prevent motion blur you have to speed up the minimum shutter speed. However raising it to 1/50sec will halve the amount of light reaching the sensor making the image darker, changing it to 1/100sec will halve the light again and so on.

Also I'd lower the WDR setting unless you need it that high as this can also cause issues with moving objects.

Hi

Thanks for the advice.

Previously I have tried to increase the shutter speed and like you say it changes the image darker and I’m not sure about what actually the WDR setting does and should I turn it off or not as if I turn it off then my night footage is in black and white.

If I leave WDR on then what setting should I have it set to as it’s on default 50 I think.
Thanks

 

[Dan]

Hi @kmb786

There really isn't a set of perfect settings which you can set the cameras to and get the best results because the same settings on 2 cameras in 2 completely different locations will give different results. it really is just a trial and error thing to see what combination works best for your scene.

WDR stands for Wide Dynamic Range and it works by combining multiple exposures, both underexposed and overexposed, to achieve an equally exposed image where you can make out detail in both the dark and light areas of the scene. With Hikvision the slider represents the balance of the exposure, so 0 will lean towards underexposed which is good for very bright scenes and 100 will lean towards overexposed for darker scenes. Most of the time being around the middle will deliver the best results.

In your case, if you are using 1/50 and image is darker then maybe pushing the WDR above 50 slightly will counteract some of that darkness. Also in regards to the WDR stopping the camera switching to IR/B&W, it may be worth walking through the scene at night with both WDR ON/colour image and WDR OFF/B&W image because sometimes the B&W image can deliver sharper clearer images than the colour image with the image enhancements enabled. (the image enhancements can increase pixelation/digital noise which can distort small details like faces)

 

[kmb786]

Hi @kmb786

There really isn't a set of perfect settings which you can set the cameras to and get the best results because the same settings on 2 cameras in 2 completely different locations will give different results. it really is just a trial and error thing to see what combination works best for your scene.

WDR stands for Wide Dynamic Range and it works by combining multiple exposures, both underexposed and overexposed, to achieve an equally exposed image where you can make out detail in both the dark and light areas of the scene. With Hikvision the slider represents the balance of the exposure, so 0 will lean towards underexposed which is good for very bright scenes and 100 will lean towards overexposed for darker scenes. Most of the time being around the middle will deliver the best results.

In your case, if you are using 1/50 and image is darker then maybe pushing the WDR above 50 slightly will counteract some of that darkness. Also in regards to the WDR stopping the camera switching to IR/B&W, it may be worth walking through the scene at night with both WDR ON/colour image and WDR OFF/B&W image because sometimes the B&W image can deliver sharper clearer images than the colour image with the image enhancements enabled. (the image enhancements can increase pixelation/digital noise which can distort small details like faces)

Hi Dan,

Thank you for your recommendations. I've been trying out the various settings for the last few hours but cant seem to get the right settig to work as like you said, the playback image of the object is pixelated. I've tried setting the exposure to 1/50 and 1/100 and turning off/on WDR but still the image is not that clear.

I'm going to see what the playback of recordings is like during the daytime and if thats ok then it's probably the night footage thats the issue.

I've also installed a 4MP ColorVu Turret today and have the same issue during the night footage playback so its definately to do with getting the right settings.

Any further advice would be much appreciated.

Thanks

 

[JB1970]

I don’t want to put a dampener on your expectations but I don’t think you’ll get that camera to produce the image you want on a night - certainly not in colour. The camera has infra red for a reason - to produce enough supplemental light to enable a correctly exposed image. Altering the settings to keep it in colour when there’s insufficient light will only make the image worse:
- Too slow a shutter speed will cause motion blur.
- Increasing the WDR can give a washed out image and produce ghosting/trailing images.
- The camera will have more visible noise in the image. By default the AGC or gain is set to 100 to enable an image in low light. That signal amplification is also amplifying the visible noise which will mask detail.
- Then there’s the DNR to contend with. The dynamic noise reduction will help “clean up” the noise in the image. It does that in two ways (that can be tweaked in expert mode). Time DNR - the processor compares the pixel to the prior one, and Space DNR - the processor compares the pixels to adjacent ones. It does this in an attempt to filter out the noise but in doing so can mask detail in the image.

You can certainly adjust the settings a little to improve the image but altering a setting to improve one aspect of the image can (and often will) negatively impact another.

To give yourself the best chance, my advice would be two cameras rather than one. By splitting that scene in two, and using a vari focal camera with a narrower viewing angle to bring the subject/target closer you’ll stand a chance of getting something more acceptable. Also either use the IR or use ColorVu to enable the correct shutter speed to be used.

 

[kmb786]

I don’t want to put a dampener on your expectations but I don’t think you’ll get that camera to produce the image you want on a night - certainly not in colour. The camera has infra red for a reason - to produce enough supplemental light to enable a correctly exposed image. Altering the settings to keep it in colour when there’s insufficient light will only make the image worse:
- Too slow a shutter speed will cause motion blur.
- Increasing the WDR can give a washed out image and produce ghosting/trailing images.
- The camera will have more visible noise in the image. By default the AGC or gain is set to 100 to enable an image in low light. That signal amplification is also amplifying the visible noise which will mask detail.
- Then there’s the DNR to contend with. The dynamic noise reduction will help “clean up” the noise in the image. It does that in two ways (that can be tweaked in expert mode). Time DNR - the processor compares the pixel to the prior one, and Space DNR - the processor compares the pixels to adjacent ones. It does this in an attempt to filter out the noise but in doing so can mask detail in the image.

You can certainly adjust the settings a little to improve the image but altering a setting to improve one aspect of the image can (and often will) negatively impact another.

To give yourself the best chance, my advice would be two cameras rather than one. By splitting that scene in two, and using a vari focal camera with a narrower viewing angle to bring the subject/target closer you’ll stand a chance of getting something more acceptable. Also either use the IR or use ColorVu to enable the correct shutter speed to be used.

Hi

thanks for your advice aswell. I’ve been looking at an old thread with recommended tweaks and it has put the picture in black and white mode so will see how it goes overnight and see what the daytime image is like. Basically the changes were

shutter speed set to 1/100
Contrast - 35
WDR - level set to 15
Smoothing level set to 1

Ive done this on both my cameras - the 8MP bullet and the 4MP ColorVu Turret I installed today to cover a different angle of my drive/property - maybe it’s just the quality I get during the night. The live footage is fine, it’s just when you playback the image of a persons face is bit blurry.

Also wanted to ask that if I set the frame rate to max and video quality to highest would that make a difference as currently frame rate is set to 25 and video set to medium.

Thank you.

 

[JB1970]

shutter speed set to 1/100
Contrast - 35
WDR - level set to 15
Smoothing level set to 1

Those settings are similar to what I would start with. The 1/100s shutter speed will help reduce motion blur. If you play with the contrast setting while the image is in monochrome, you'll see that lowering it will help to lighten areas in shadow much like WDR does. Only use the WDR at all if you need it - if you add it when it's not needed it'll negatively impact the overall image. Where the effect of the WDR may be visible is between the hedge and car - it will lighten that area evening out the exposure. The smoothing setting will push up the bit rate of the camera so it may be best not to push it all the way to 1.

The live footage is fine, it’s just when you playback the image of a persons face is bit blurry.

That's not to be unexpected. A persons face in the view that you've shown may not be resolved by a sufficient number of pixels for the detail that you want especially on night when the camera has insufficient light. Don't use the digital zoom to assess the image quality. If the face isn't large enough in the image then digitally zooming the image beyond it's native resolution will make it look worse. If a face is too small in the image when the image is viewed at it's native size, then that's not a failing of the camera, you've simply selected the wrong lens or in the case of your variable focal model set it too wide.

Also wanted to ask that if I set the frame rate to max and video quality to highest would that make a difference as currently frame rate is set to 25 and video set to medium.

Maximum frame rate and 25fps are the same. The higher the frame rate you use, the higher the bit rate that's required. The lower the compression level (higher quality) you use, the higher the bit rate that's required. Use a lower frame rate if that's all you need with a higher quality (lower compression level) and higher bit rate. There's no perfect frame rate. How many still images do you need in one second in order to capture what you need. If a target was moving across the field of view, perhaps a high rate might be necessary but if the target is moving toward the camera (as in your example by the looks of it) not so necessary.

A question that's often seen on here "Whats the best camera - I need to be able to identify faces and read number plates on a night". It's unrealistic unless you have very deep pockets!

Looking at the spec - the 2685G0 dark fighter you've used has a minimum illumination of 0.011 which isn't the best. The newer G2 models work down to 0.003. While I'd be careful reading too much into the manufacturer's spec, they may be some use when comparing models.

 

[kmb786]

Those settings are similar to what I would start with. The 1/100s shutter speed will help reduce motion blur. If you play with the contrast setting while the image is in monochrome, you'll see that lowering it will help to lighten areas in shadow much like WDR does. Only use the WDR at all if you need it - if you add it when it's not needed it'll negatively impact the overall image. Where the effect of the WDR may be visible is between the hedge and car - it will lighten that area evening out the exposure. The smoothing setting will push up the bit rate of the camera so it may be best not to push it all the way to 1.


That's not to be unexpected. A persons face in the view that you've shown may not be resolved by a sufficient number of pixels for the detail that you want especially on night when the camera has insufficient light. Don't use the digital zoom to assess the image quality. If the face isn't large enough in the image then digitally zooming the image beyond it's native resolution will make it look worse. If a face is too small in the image when the image is viewed at it's native size, then that's not a failing of the camera, you've simply selected the wrong lens or in the case of your variable focal model set it too wide.


Maximum frame rate and 25fps are the same. The higher the frame rate you use, the higher the bit rate that's required. The lower the compression level (higher quality) you use, the higher the bit rate that's required. Use a lower frame rate if that's all you need with a higher quality (lower compression level) and higher bit rate. There's no perfect frame rate. How many still images do you need in one second in order to capture what you need. If a target was moving across the field of view, perhaps a high rate might be necessary but if the target is moving toward the camera (as in your example by the looks of it) not so necessary.

A question that's often seen on here "Whats the best camera - I need to be able to identify faces and read number plates on a night". It's unrealistic unless you have very deep pockets!

Looking at the spec - the 2685G0 dark fighter you've used has a minimum illumination of 0.011 which isn't the best. The newer G2 models work down to 0.003. While I'd be careful reading too much into the manufacturer's spec, they may be some use when comparing models.

Many thanks for this info.

I will give the contrast settings another tweak when it’s dark but may have to wait as we’ve had heavy snow so the footage will probably be in colour tonight on the bullet camera with all the white covering of snow etc.

I did just check the daytime playback just now and the image quality is much better so it’s just the settings that I need to get to the best as possible.

thanks

 

[kmb786]

Currently my bitrate settings are as follow for main stream/sub-stream

8MP bulltet = 5120 kbps/2048 kbps
4MP ColorVu = 6144 kbps/2048 kbps

Are the above OK or should I increase them?

Also, Smoothing level set to 1 - What should I realistically set this to?

Thanks

 

[fullboogie]

There's a chart floating around on here about what type of main stream bit rate you should need based on camera specs. I found it to be very good. Keep in mind that "maximum bitrate" does nothing directly to the camera's settings. It only sets a ceiling - a limit - on the bitrate.

 

[kmb786]

There's a chart floating around on here about what type of main stream bit rate you should need based on camera specs. I found it to be very good. Keep in mind that "maximum bitrate" does nothing directly to the camera's settings. It only sets a ceiling - a limit - on the bitrate.

Thanks - I’ve just googled and found it so will have a look. I’ve attached it

 

[JB1970]

Currently my bitrate settings are as follow for main stream/sub-stream

8MP bulltet = 5120 kbps/2048 kbps
4MP ColorVu = 6144 kbps/2048 kbps

Are the above OK or should I increase them?

Also, Smoothing level set to 1 - What should I realistically set this to?

Thanks

You don't mention your frame rate there with regard to those settings but the table provided is a good starting point. I believe that's based on medium quality setting, so if I set mine to Higher I generally add about 30 percent to the figure given - that's for the main stream. Whatever bitrate you set, even when using variable, the camera will eat it up. Don't imagine you'll be able to set it high enough that when you check the statistics while live viewing, the actual bit bit rate will be lower than what you've set - never happens. It'll fluctuate and burst above your setting to some extent. Be careful with the smoothing. I've previously recommended setting this all the way to 1 but have found that this setting along with setting the quality to highest (as @Dan has detailed in a previous post) can cause the bit rate to burst way too high on the 8MP cameras and cause issues - dropped frames, lack of resources for other connected cameras potentially.

Sub Stream bit rate - WAY TOO HIGH! The sub stream is what you're going to be looking at while out and about on your mobile device - a small phone screen. As such it needs to be low enough for use on the mobile network or the flakey WiFi in the pub (definition: pub/boozer/public house - an establishment where one could relax, have a beer, socialise and watch the football - unavailable for safe use since early 2020). While we all have 4G these days, there are frequent occasions where despite showing all the bars, the download speed is too low to support that connection, due to the providers network. I tend to leave mine on H264, constant bit rate (more predictable actual bit rate on an unknown network), 12 FPS (more than enough) and 768 kbps. Better to have the sub stream low - you can always switch stream if necessary during remote viewing.

In summary:

Main Stream - use the tables as a starting point, increase by 20-30 percent if using Higher, watch your Smoothing level.
Sub Stream - H264, CBR, keep below 1024 kbps to avoid connection issues on mobile.

 

[kmb786]

You don't mention your frame rate there with regard to those settings but the table provided is a good starting point. I believe that's based on medium quality setting, so if I set mine to Higher I generally add about 30 percent to the figure given - that's for the main stream. Whatever bitrate you set, even when using variable, the camera will eat it up. Don't imagine you'll be able to set it high enough that when you check the statistics while live viewing, the actual bit bit rate will be lower than what you've set - never happens. It'll fluctuate and burst above your setting to some extent. Be careful with the smoothing. I've previously recommended setting this all the way to 1 but have found that this setting along with setting the quality to highest (as @Dan has detailed in a previous post) can cause the bit rate to burst way too high on the 8MP cameras and cause issues - dropped frames, lack of resources for other connected cameras potentially.

Sub Stream bit rate - WAY TOO HIGH! The sub stream is what you're going to be looking at while out and about on your mobile device - a small phone screen. As such it needs to be low enough for use on the mobile network or the flakey WiFi in the pub (definition: pub/boozer/public house - an establishment where one could relax, have a beer, socialise and watch the football - unavailable for safe use since early 2020). While we all have 4G these days, there are frequent occasions where despite showing all the bars, the download speed is too low to support that connection, due to the providers network. I tend to leave mine on H264, constant bit rate (more predictable actual bit rate on an unknown network), 12 FPS (more than enough) and 768 kbps. Better to have the sub stream low - you can always switch stream if necessary during remote viewing.

In summary:

Main Stream - use the tables as a starting point, increase by 20-30 percent if using Higher, watch your Smoothing level.
Sub Stream - H264, CBR, keep below 1024 kbps to avoid connection issues on mobile.

Hi

Thanks for this which I will also try out.

The cameras are set to 25fps

What Smoothing level should I set or shall I keep the default which is 50.

Does viewing from mobile device/mobile data automatically use the Substream or do I have to do something ?

Dan has also replied to another thread of mine regarding video quality settings etc so I’m just waiting for a reply from him on a few queries.

Thanks

 

[JB1970]

Hi

Thanks for this which I will also try out.

The cameras are set to 25fps

What Smoothing level should I set or shall I keep the default which is 50.

Does viewing from mobile device/mobile data automatically use the Substream or do I have to do something ?

Dan has also replied to another thread of mine regarding video quality settings etc so I’m just waiting for a reply from him on a few queries.

Thanks

I found in improvement in lowering the smoothing toward clear but it does have a large impact on bit rate - the I frame seems to be much larger (the I frame is a full frame refresh of the frames in between them are only updating changed pixels) If you can't notice any difference then leave it as is.

It depends on what you are using for remote viewing. In Hik Connect - Basic would use the sub stream whereas HD uses the Main Stream. You just select that in the lower left hand corner of your phone while viewing the image.

 

[kmb786]

I found in improvement in lowering the smoothing toward clear but it does have a large impact on bit rate - the I frame seems to be much larger (the I frame is a full frame refresh of the frames in between them are only updating changed pixels) If you can't notice any difference then leave it as is.

It depends on what you are using for remote viewing. In Hik Connect - Basic would use the sub stream whereas HD uses the Main Stream. You just select that in the lower left hand corner of your phone while viewing the image.

Thanks - yes I’m using Hik Connect using HD mode as the BASIC mode doesn’t give me good quality.

 

[JB1970]

Thanks - yes I’m using Hik Connect using HD mode as the BASIC mode doesn’t give me good quality.

The resolution for the sub stream is quite low around 4CIF - which in the early days of IP was considered to be "analogue equivalent" for those of us who'd been used to specifying resolution in TV lines for the previous 20 years! It still should be fine for normal usage on your mobile even if it looks a bit "soft". You rarely need to be pixel peeping on your mobile when you're looking at your cameras.

 

[kmb786]

The resolution for the sub stream is quite low around 4CIF - which in the early days of IP was considered to be "analogue equivalent" for those of us who'd been used to specifying resolution in TV lines for the previous 20 years! It still should be fine for normal usage on your mobile even if it looks a bit "soft". You rarely need to be pixel peeping on your mobile when you're looking at your cameras.

Thanks - is there much difference between Higher and Highest video quality and if there is, how much percentage should I add to the bitrate figure in the recommended chart for the mainstream setting running at 25fps.

 

[JB1970]

Thanks - is there much difference between Higher and Highest video quality and if there is, how much percentage should I add to the bitrate figure in the recommended chart for the mainstream setting running at 25fps.

I don't see a big difference to be honest. I've previously set a camera at Highest quality and maximum bit rate one night and changed it to Higher with a much lower bitrate the next and compared motion and still images - not a great difference. The law of diminishing returns applies - you can use a lot more bandwidth for a negligible improvement in quality. You'll get differing opinions on how high to set the bit rate - some recommend setting at to the max but I never have. I usually use that table and then add an additional 25 percent if I use higher and 50 percent or more if I use highest. The camera will try and use the bit rate that you've set so if you set a bit rate too low for the quality selected you could end up with a worse image while using a Higher quality setting. The bit rate used/required will be dictated by the amount of the motion in the image (proportional to the full image), the frequency of that motion and the compression level (Quality). That's why there are no magic settings as every scene is different. I wouldn't get too hung up on the numbers - as long they're higher than those in the chart you won't go far wrong.