advice picking between low light cameras? (DS - 2CD2135FWD I)

Discussion in 'Hikvision' started by Cjy, May 24, 2019.

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  1. Cjy

    Cjy n3wb

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    hi i was reccomended on this forum to get this turret dahua camera as an affordable low light camera Review-Dahua IPC-HDW2231RP-ZS Starlight Camera-Varifocal

    i was previously looking at the hikvision DS-2CD2135FWD-I
    US $107.0 |free shipping english version DS 2CD2135FWD I replace DS 2CD2135F I 3MP Ultra Low Light Network Dome Camera-in Surveillance Cameras from Security & Protection on Aliexpress.com | Alibaba Group

    both are similarily priced, the main difference is the lack varifocal and it being a dome(which i've heard has a lot of downsides) from hikvision but am i correct in thinking the hikvision will actually work better in capturing colour in low light?

    Both have 1/2.8” image sensor but in minimum illumination

    the hikvision says
    Color: 0.005 lux @(F1.2, AGC ON), 0 lux with IR

    the dahua turret says
    0.006Lux/F1.4( Color,1/3s,30IRE)
    0.05Lux/F1.4( Color,1/30s,30IRE)
    0Lux/F1.4(IR on)

    it doesn't explain the shutter speed on the hikvision but the dahua seems limited capturing colour during low light? 1/3s sounds bad but i'm not entirely sure how dark 0.05 to 0.006 lux is, like would i need to capture in such low light. As i stated i have no idea what shutter speed the hikvision would operate at either. any advice or experience would be greatly appreciated.

    i intend to use it for my takeaway shop which is well lit during opening times but also has some street lighting when closed. i'd love varifocal but evidence gathering is more important for my shop.

    thanks
     
  2. reeves1985

    reeves1985 Pulling my weight

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    This is my starlight dahua ptz
    Has roughly the same lux rating as the one you mention.

    Note:
    No extra lighting other than streetlights
     

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  3. Cjy

    Cjy n3wb

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    thanks for the reply,
    that looks pretty decent, street lights are on the other side from my shop however so its kind of dimly lit, could you link the model number so i can compare specs?
    also are there any issues capturing moving objects (faces and cars) at night?
     
  4. reeves1985

    reeves1985 Pulling my weight

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    Regarding moving objects l, if your sensible with your assumptions before you start and know what limitations the camera will have in terms of its ability then you can reach a happy medium.

    It will capture people walking past etc without too much trouble, but cars that move fast over 20mph then you will get some blur.

    Model number for the PTZ is SD59225U-HNI
    It's rated as low as 0.005 for colour @F1.6

    But the the turret I have which is IPC-HDW5231R-ZE is a tad better that that in low light.

    I don't have a snap handy of that one but I'll gladly post one up tonight if you want me to
     
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  5. aristobrat

    aristobrat IPCT Contributor

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    I'd think they'd both do well in low-light, but I'd give the Dahua a slight edge. One of the big things that helps with low-light image quality is the size of pixels... bigger pixels allow more light down to the image sensor. With both cameras having the same sized sensor (1/2.8"), but the Dahua having 1MP fewer pixels (2MP vs 3MP), that would make the pixel size on the Dahua a little bigger than the Hik's.

    One thing to read up on if you go with a dome is the potential for an issue with IR reflecting. If you have the dome setup in a manner where the IR that shoots out at night reflects back off of something (walls, large objects, etc) towards the camera, that can really wash out/ghost the image. Forum gets a couple posts a month with folks trying to solve this issue.

    Varifocal has a big potential to help you with gathering evidence. It will allow you to zoom in tighter on a key area, which increases the PPF (pixels per foot). The general recommend to ID someone that you don't know is that the PPF should be >= 100. There's a cool online tool that you can play with to see PPF in action ... IPVM Camera Calculator V3 ... if your'e going to be using this cameras on the outside of your shop, you can type in the address, let it pull up the Google Map image of your shop, add a camera to the image, change the camera model, drag the camera where you'd like it on the outside of the shop, then drag the little guy around to various distances... it should show you a simulated image which includes the calculated PPF. If you happened to add a varifocal camera to the map, you can change the zoom of the varifocal and watch the PPF increase/decrease. Also note that the width of the image will increase/decrease as you zoom in. One of the tradeoffs with zooming in to get a higher PPF is that the image will be more narrow and may not get everything in the shot. In this situation, it's not unusual to see folks use two cameras ... one zoomed in on a key area (i.e. high PPF on a door, gate, car in driveway, etc), then another camera with a much wider angle used as an overview camera. The overview camera won't have a good PPF (unless the person happens to stand very close to the camera) so it'd be challenging to ID someone with that camera <, but it's often useful to see a wide image.

    As for moving objects at night, ... these low-light cameras help reduce that a lot <compared to regular cameras>, but they're not magic -- it can still be a challenge to get blur-free motion in low light. A faster shutter speed helps reduce motion blur. The side effect of a faster shutter speed is that the sensor has less time to gather light, so images come out darker. Sometimes more IR is required to help with that.
     
    Last edited: May 24, 2019
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  6. Cjy

    Cjy n3wb

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    thanks for the info, it seems like all these cameras should a decent compromise on price performance, my shop sits on a cross roads with speed bumps so cars have to slow down anyway.

    The turret you have was also highly recommended, the dahua turret i posted was said to be like a smaller cheaper brother.

    nah don't trouble yourself mate, i trust your opinions ha

    cheers
     
  7. aristobrat

    aristobrat IPCT Contributor

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    If you haven't already stumbled across it, the 2231 has a decent review thread here:
    Review-Dahua IPC-HDW2231RP-ZS Starlight Camera-Varifocal

    For ordering, check out the Cliff Notes document and do a CTRL-F search for Andy (@EMPIRETECANDY). For years he's been getting kudos for being easy/reliable to order from, plus he ships worldwide using DHL. Awesome guy.
     
  8. Cjy

    Cjy n3wb

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    thanks aristobrat... again lol.

    i was just checking the shutter speed and 1/3s capturing a moving car i saw on youtube looked like a still image moving along the road.

    but yeah, i think i'm pretty much dead set on one of these turrets. The ipvm calculator sounds awesome and i'll look into it, again thanks for your time and input.
     
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  9. reeves1985

    reeves1985 Pulling my weight

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    That's exactly what I do.
    I've got the PTZ usually on overview and the turret zoomed into my front gate for aid of id if ever needed.
     
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  10. Cjy

    Cjy n3wb

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    hi there, this might sound like a stupid question but do you know what type/size cable gland is needed for the IPC-HDW5231R-ZE junction boxes(PFA130-e)? i just received the boxes and realised they don't come with any...
     
    Last edited: May 28, 2019
  11. reeves1985

    reeves1985 Pulling my weight

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    Measure the size of the hole and if you are UK based then that measurement is your Number for the gland size