DS-2CD2387G2-LU 4mm 8MP ColorVu out of focus, black pixels when zoomed in?

triumph202

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Has anyone else got a 4mm version of the newish 8MP ColorVu turret? I just bought one and it seems to have been focused very poorly at the factory- that's testing it inside and not expecting anything really close to be in focus.

I also noticed when zooming right in on the NVR playback there were a few random black pixels. (Like dead pixels on the sensor?)
 
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triumph202

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Okay, an update- both of the problems appear to be related to the bitrate I'd set it up at. The focus could still be better IMHO.
 
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alastairstevenson

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The focus could still be better IMHO.
With the large aperture F1.0 lens, there is reduced depth of field over the usual smaller aperture lenses.
So the choice of focus point is a slight compromise, as is indicated by Hikvision now including it in the device specs.

From the Hikvision specs :
Depth of Field
2.8 mm: 3.1 m to ∞
4 mm: 3.6 m to ∞
 

triumph202

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With the large aperture F1.0 lens, there is reduced depth of field over the usual smaller aperture lenses.
So the choice of focus point is a slight compromise, as is indicated by Hikvision now including it in the device specs.

From the Hikvision specs :
Yes, I'm aware of the reduction in the depth of field with a larger aperture opening. I also checked the specs prior to buying and know about the 3.6m to infinity - I'm talking about the focus on things past the 3.6m distance.

I'll get it set up outside today and see how it looks (focus wise) then.

I've got some older fixed lens DS-2CD2335FWD-I and two of the varifocal model (edit ds-2cd2h35fwd-izs.) A couple of the fixed lens versions were out of focus new (or had soft focus in some areas), so I'm wondering if it might be the same case here? The varifocal model in that range seems to have a better quality lens.
 
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Uhdcam

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With the large aperture F1.0 lens, there is reduced depth of field over the usual smaller aperture lenses.
So the choice of focus point is a slight compromise, as is indicated by Hikvision now including it in the device specs.

From the Hikvision specs :
I’m quite a newbie to this but does this mean that anything less than 3.1m is out of focus?
 

wittaj

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I’m quite a newbie to this but does this mean that anything less than 3.1m is out of focus?
That would be correct. Some field of views will be more noticeable than others.
 

triumph202

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I’m quite a newbie to this but does this mean that anything less than 3.1m is out of focus?
Yes, as already mentioned anything closer than that range will go out of focus. Mine also has an issue with the far LHS of the frame being slightly soft in focus compared to the rest of the frame (at all distances.)
 

ljw2k

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Yes, as already mentioned anything closer than that range will go out of focus. Mine also has an issue with the far LHS of the frame being slightly soft in focus compared to the rest of the frame (at all distances.)
This could be a QC issue and the lens not seated proper over the sensor. Heat can sometimes cause this focus issue in corners especially in Hot countries where you are.
 

triumph202

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This could be a QC issue and the lens not seated proper over the sensor. Heat can sometimes cause this focus issue in corners especially in Hot countries where you are.
It's there all the time - be it over 30C or below 10C.

I could pull it apart and try to manually adjust the focus, but the luckily the side affected isn't within the area we're most concerned about monitoring. If it was on the RHS I would be looking into it further.

Edit: I've had similar issues on other low light Hik cameras with fixed lenses. Their equivalent varifocal models seem a lot more consistent with the focus being the same over the entire frame.
 

venturis

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It's there all the time - be it over 30C or below 10C.

I could pull it apart and try to manually adjust the focus, but the luckily the side affected isn't within the area we're most concerned about monitoring. If it was on the RHS I would be looking into it further.

Edit: I've had similar issues on other low light Hik cameras with fixed lenses. Their equivalent varifocal models seem a lot more consistent with the focus being the same over the entire frame.
Just picked up a 2CD2387G2-LSU/LU with 4mm lens last week. Its not installed yet for lack of time but on the bench for testing. Let me know if you have any tests you want performed to compare images. A standard test image is going to give the best comparison.
 

triumph202

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Let me know if you have any tests you want performed to compare images. A standard test image is going to give the best comparison.
It will be obvious when it's installed if there is the same problem. Mine looks out over my double width paver driveway, it's obvious the LHS of the screen has soft focus no matter what the distance. (When viewing the pavers, tree leaves etc.)

It will be interesting to see what you think once it's installed.

Did you buy it within Australia or from O/S?
 

venturis

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I've managed to do some side by side testing with my 2CD2386G2.

Whilst the 2387G2 focus does look consistent across the entire image, the 2386G2 gives a much sharper image with more detail. See attached images which have been cropped from the full image frame and zoomed. The cams are at different vantage points and the 2CD2387G2 is a couple of metres further away from the target..

Fine details such as number plates can be read at 20meters with the 2CD2386G2 but not remotely possible with the 2CD2387G2.

The 2CD2387G2 is definitely a softer image. Using identical settings for bit rate, frame rate, resolution etc on both cams. H265+ on and identical 4mm lenses on both.

Brief testing at night reveals the 2CD2387G2 produces a vastly brighter image but not confirmed yet if brighter necessarily means better if it is at the expense of loss of details. Definitely less ghosting of moving objects and still a good amount of brightness even at higher shutter speeds.

I purchased the camera from Aliexpress. Was $300 Australian shipped with a discount voucher and cashback. Took around 2 weeks to arrive. I couldn't bring myself to pay the $480+ asking price of local retailers.

mpv-shot0001_cropped.jpgmpv-shot0002_cropped.jpg
 

wittaj

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TBH both of those images look poor. Almost looks substream or too much macroblocking because of using H265+.

Can you try H264 and 10,000 bitrate at 15FPS and post those results?
 

venturis

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TBH both of those images look poor. Almost looks substream or too much macroblocking because of using H265+.

Can you try H264 and 10,000 bitrate at 15FPS and post those results?
Just to be clear,both images have been cropped from a full frame. What you see in the samples are only 5% or less of the full scene. It was intended to show the level of detail discernible of objects at a distance.

Both samples were taken using the same video settings of full 4K, 15fps, h265+ average bitrate 4096 (max 8192), highest quality, noise reduction 50%

What it shows is that the 2cd2386g2 image is much sharper than the 2cd2387g2 for the same conditions.

It could be one cam is better focussed or just the consequence of the different sensors and lens aperture?
 
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triumph202

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Try out plain H265 and h264. I think I've got mine set to h264 as the detail is clearer. Your bitrate is low for an 8MP camera, but I guess your FPS is lower too. I've got mine set to variable at around 11000.
 

venturis

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I did try plain H265 and it made no difference to image quality so bumped it back to H265+

The purpose of the images was to gauge the clarity of the image against a known benchmark to see if it was as least as good, same or worse. I deliberately used the same settings in both cams to rule out the settings influencing the results.

What it shows is that the 2CD2387G2 image is softer than the comparable 2CD2386G2. I would have to say the 2CD2387G2 is probably slightly out of focus.

Generally, when looking at the whole frame for the 2CD2387G2 there is less crispness in the image. The lines between the pavers my driveway are not as sharp as well as other tell-tail indications the focus is not optimal.
 
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triumph202

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Are you using an NVR? With H265+ and H264+ I've always had bizarre issues crop up after a couple of days (corrupt frames etc.) Give H264 a go and see if it's better, do you have enough bandwidth to bump the bitrate up too? My NVR limits me to an average of around 10000 per channel.

I don't have another 8MP camera to compare mine to. Apart from the LHS of the frame mine seems focused okay to me. It replaced a 3MP varifocal "powered by Darkfighter" camera.
 

venturis

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Are you using an NVR? With H265+ and H264+ I've always had bizarre issues crop up after a couple of days (corrupt frames etc.) Give H264 a go and see if it's better, do you have enough bandwidth to bump the bitrate up too? My NVR limits me to an average of around 10000 per channel.

I don't have another 8MP camera to compare mine to. Apart from the LHS of the frame mine seems focused okay to me. It replaced a 3MP varifocal "powered by Darkfighter" camera.
Yes. connected to a 7608NI-I2/8P NVR. Never had issues with H265+. I have G1, G3 and now G5 platform 8MP cams connected to the unit and not had issues (touch wood).

I deliberately stay away from H264 since it consumes too much bandwidth/storage for my liking.

I will give the higher bitrate a go and see it there is improvement.
 

triumph202

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connected to a 7608NI-I2/8P NVR
That's the same as mine. You've got 80Mbps total incoming bandwith- so 10Mbps per channel (averaging it.) Increasing the bit rate will improve the picture detail.


I did a screen capture (jpg) on the NVR to show the LHS focus issue, it doesn't really show it up as much as the live view on a 55" TV. Compare the two circled areas. (It's a jpg so the overall quality isn't as good as the actual picture.)

8MP Colorvu focus - Copy.jpg
 
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