Worlds First Review - Dahua - IPC-Color4K-X / DH-IPC-HFW5849T1-ASE-LED - Full Color 4K Camera

Vaikis

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would like to see Night and Day profile settings, anybody can share ? Is there any benefits for this cam to have such ? :)
 

wittaj

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I have found this camera to be so good that it is my only camera that runs the same profile day and night. The shutter can be ran so much faster on this camera. YMMV.
 

wartex11

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Hi guys,

Which is the 5442 camera with colour at night in the comparison videos?



I've purchased the first one (black and white at night?), and a IPC-Color4K-X from Andy, looking to get another colour one for the front of the house

Thanks a lot,
 

NightLife

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I have found this camera to be so good that it is my only camera that runs the same profile day and night. The shutter can be ran so much faster on this camera. YMMV.

I'm also using the same profile day/night. I run 'Night' settings full time, with the modest supplemental dusk to dawn light bulb I'm using.
 

Alaska Country

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Hey guys, The 6mm will be released next month.
Will the 6mm have a close focus distance in the range of 23 to 25 Feet? i.e. the 2.8mm is rated at 10.2 feet and the 3.6 mm at 17.7 feet

Is it possible to adjust the lens (take apart the camera) and refocused to a closer distance of 10 feet as an example? Can see why folks may like this camera in a variable focal model in addition to the present fixed lens models.
 

quest100

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When I saw the possibility of the Color-4k-X (5849) being available with a 6 mm lens I thought perfect! I want one! Or two or...

Then I started looking at the FOVs for this camera and other Dahua cameras with fixed 2.6, 3.6, and 6 mm lenses. I wanted to make sure the the FOV would be correct for my applications.

I created the following table where I calculated the HFOV and VFOV for 1/2.8, 1/1.8., and 1/1.2 inch sensors versus the three fixed focal lengths used by Dahua. I then added the FOVs from some Dahua data sheets. This is what I get:

Lens ➡
⬇ Sensor or Camera
2.8 mm3.6 mm6 mm
Sensor - (H, V) mmFOV - (H, V) degrees
1/2.8” - (5.57, 3.13) mm89.7 x 58.475.5 x 47.049.8 x 29.2
IPC-HFW4239T-ASE 87 x 47 (Garage Left)54 x 20 (Corner)
1/1.8” - (7.80, 4.41) mm108.6 x 76.494.6 x 63.066.0 x 40.4
IPC-HFW5449T-ASE-LED 107 x 6095 x 5158 x 31
IPC-HDW5442TM-ASE 113 x 6089 x 4856 x 31
1/1.2” - (11.14, 6.26) mm126.6 x 96.4114.2 x 82.085.7 x 55.1
IPC-HFW5849T1-ASE-LED112 x 6191 x 50 (Garage Right)

Now I am confused as to what the FOV will be and what it actually is for my existing cameras. My calculations don't come close to what the data sheets show. Even worse, the FOVs don't increase as I would expect as the sensor gets larger. Look at the specs for the cameras with 3.6 mm lenses. Each camera has a HFOV close to 90 degrees (87, 95, and 91 degrees). The FOV should be increasing as the sensor gets larger (75, 95, and 114 degrees).

I don't expect the sensor sizes are wrong or that the lenses being used have enough distortion to have this effect. Could Dahua be using some sort of equivalent focal lengths, much like how digital cameras often use 35 mm film equivalents?

I compared the images from my 4239 and 5849 cameras on the sides of my garage. Both are supposed to have 3.6 mm lenses. The FOV of the 1/2.8" camera should cover exactly half of the image from the 1/1.2" camera - same size pixels, twice as many horizontally and vertically. Instead the 1/1.2" camera seems to have just a slightly larger HFOV, agreeing with the spec sheet.

Anybody else notice this and/or have an explanation?
 

wittaj

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Not specific to this camera, but it has been noted before the differences. Here is one such thread

 

tigerwillow1

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I don't expect the sensor sizes are wrong or that the lenses being used have enough distortion to have this effect. Could Dahua be using some sort of equivalent focal lengths, much like how digital cameras often use 35 mm film equivalents?
This was my conclusion when I went through the FOV calculation exercise a year or two ago. There are too many unknowns to do much but actually measure the camera's FOV. The stated sensor size is normalized to the equivalent size of old TV image tubes. Then it's rounded to a close common size, like 1/2.8. And I suspect that Dahua is doing some fudging to help with camera spec comparisons. Bottom line for me is to use Dahua's FOV spec, hoping it's correct. Andy's published specs are a lot more reliable than some other vendors. I think some of the ebay vendors list the first specs they can find, not caring if it's actually for the camera it's listed with.
 
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