Common issues with camera image

Fishman57

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Thank You ! I`ll have to read this a few times but it covers so many common problems! Excellent.
 

Dave Lonsdale

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As reported by others wopi, many thanks for your very informative post. Having both starlight and non starlight 2MP Dahua cameras, I have a related query regarding sensor performance. The sensor sizes and other parameters appear to be similar and so I ask, is the huge 10x difference in the minimum illumination specification attributable exclusively to sensor performance?

If it was partly down to signal processing or whatever, could this be at the expense of compromises described in your post? In my rudimentary tests, by the way, differences in the starlight/non starlight low light performance don't seem to be as pronounced as I would have imagined.
 

Dave Lonsdale

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Hi wopi, I have 11 cameras around my home, all Dahua and are as follows:-

1 x SD3282D-GN (initial Dahua purchase in late 2013)
1 x HDW4221EM (focus not brilliant but the lens assembly is glued together in this model)
1 x SD22204T-GN
1 x SD29204T-GN
1 x HDW4300C
starlights:-
4 x HFW8231E-Z (purchased soon after Dahua launched starlights in 2016. I had ordered the HFW8281E-Z but was not available)
1 x SD59225U-HNI
1 x HDW5321R-ZE
 

Dave Lonsdale

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To add a little information about my very basic sensor comparison test, I think I recall reducing the shutter time by around 3x to get a broadly similar image brightness on the starlight camera (not 10x if it’s merely a simple linear relationship). However, without noise reduction, the image was more noisy. Doesn’t this also mean that some of the improvement is actually more gain?

Unfortunately, the test I did was a long time ago and I didn’t make notes. Of course, the cameras are not otherwise identical and I could easily have screwed up the settings. Although I guess I could climb a ladder etc to put two cameras together to have another go, I would have far more confidence in your expert appraisal wopi.
 

CCTVCam

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What about the effects of bitrate?
I guess that's going to depend on whether the OP has the footage wants to put the extra time in assembling it. The effect of shutter as I described above could also do with an example. Too fast a shutter looks almost like the Digital Aberrations where the car hops or stutters, except without the accompanying pixelation. Too slow will be blurry. Bit rate will show aberrations / artefacts if too low and if too high will eat storage space but with no real detriment other than storage and no noticeable improvement to the picture quality beyond what could have been achieved with a lower rate.
 

wopi82

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@Dave Lonsdale
This is, what you have in your cameras:
SD3282D-GN 1/3" 2MP
HDW4221EM 1/3" 2MP
SD22204T-GN 1/2.7" 2MP
SD29204T-GN 1/2.7" 2MP
HDW4300C 1/3" 3MP

starlights
HFW8231E-Z 1/2.8" 2MP (IMX290)
SD59225U-HNI 1/2.8" 2MP (IMX290)
HDW5231R-ZE 1/2.8" 2MP (IMX290)

So basically you were comparing old era sensors with first generation of Starvis, which is IMX290. I wouldn’t expect enormous difference between these, but obviously there should be clear distinction. Sensor performance is not about image brightness, but rather image clarity (noise level). If old sensors were described as 0.05lux and new one as 0.005lux, it means that if you rise GAIN of new sensor by about 3EV, you should get similar noise level. In other words, if an old camera was doing well at 1/30s exposure, the new one should achieve same quality at around 1/240s exposure, while maintaining same image brightness. The scale is logarithmic. Of course lens brightness also counts here.
 
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Dave Lonsdale

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Hello wopi, many thanks for your reply. As you have explained, it’s important for me to discover that (unfortunately) the scale is logarithmic when making comparisons. It’s also interesting to know that sensor performance has further improved. However, being a pensioner, unless my cameras die or I have a robbery I am unable to justify buying new generation cameras. I’ll have to make do with a bit more illumination.
Thanks again wopi.
 

Dave Lonsdale

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Useful information! I loved to read this and add some more when lost videos or photos on security camera. recovery can be done irrespective of the reason of the loss. I personally used software like **(edited by fenderman) which support all formats of images and video files that DVR/NVRs recover from Wi-Fi security cameras. Thanks!
Hello Jason. Did you drink at least two bottles of wine before writing your first post?
 
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jasonWM

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Hi Dave, Basically I read whole the post Common issues with camera images, and I just explained which I have observed in my experience regards camera issues!
 

fenderman

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Hi Dave, Basically I read whole the post Common issues with camera images, and I just explained which I have observed in my experience regards camera issues!
You are a garbage spammer. Dont you know what happens to spammers here?'
Anyone on the internet who finds this on a google search (they will because of the size of this forum) dont not use Stellar Photo recovery software, they are scammers, spammers and fraudsters.
 
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vcwannabe

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Thank you! Overall I have been happy with the results I have been getting, but your tips will help me know what I need to do to finetune each area.
 

wittaj

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I have referred to this post often since it was posted - excellent!

@wopi82 - I do have a question. You mention "Avoid leaving factory settings. Also avoid setting fixed shutter values like 1/200s or so. Operate on millisecond values and set ranges. If you want your camera to operate at night at 1/100s, set a range from 0ms to 10ms. This way the camera will have a potential to shorten the exposure if the scene gets too bright, so the image will not get overexposured."

Can you explain this in more detail - what does the lower end value mean or equate to and what does the higher end value mean or equate to.

Like one of my offbrand cameras has it set 10ms to 65ms - but I have no idea what that really means? And I haven't been able to find a good explanation using the search function.
 

aristobrat

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I think that lets the camera dynamically adjust the shutter speed between the ranges of 1/15 - 1/100 based on how bright the scene is. 1/15 = 64.93ms, so not quite 65ms but pretty close.
 
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