FOV or angle of view on the DS-2CD2342WD-I

[tomhanman]

Hello all you knowledgeable folk,

Can anyone help give me some definitive FOV angles for the 2.8, 4 and 6mm lenses on this cam?

I have found 90°,60°,46° from use-IP.co.uk
106°,83°,X° from networkwebcams.co.uk
X,69.9°,50° from a Chinese supplier I'm thinking of using; hofotech.com
106°, 83°, 56° from the Hikvision site: http://overseas.hikvision.com/us/Products_accessries_10508_i7593.html

Anyone have enough confidence to confirm any of those figures? And please god don't tell me there are various versions using different chips giving different FOV angles with the same lenses. I can't take any more variables!!

Thanks,
Tom.

 

[tomhanman]

I would never have believed that such an elementary piece of information could be so hard to determine.

 

[blake]

I know this has been coveted on here before somewhere. I would try googling fov calculator. That will give you a general idea.

 

[tomhanman]

I know that people have talked about FOV, and I know that calculators exist mostly for photography, but they depend on other information like EXACT sensor size etc. which I am not sure we have (1/3" is very approximate). I simply want the correct figures for this precise camera as I can't plan which to purchase to cover my site without this info. I don't really know why we even bother listing the focal lengths and resolution for these things when that is of no use if we don't have an accurate FOV.
Thanks anyway.

 

[Kawboy12R]

I find that my 3345-I 6mm is most accurate when using the FOV of IPVM.com/calculator when used with the 1/2.5mm sensor size. This measurement has been discovered/measured online with a disassembly of Hik cams rather than depending on their published stats of 1/3" for the sensor.

 

[tomhanman]

Thanks for that Kawboy. The site is great, lots of fun! But I find it hard basing such a big investment on the idea that the sensor is 1/2.5" rather than 1/3" as advertised. I'm sure you're right... but that's not to say it goes for all their cameras... I would find it easier to believe if they were using smaller sensors than claimed, but if they are using larger ones I'd expect them to be shouting about it.

Basically I understand that one can't believe much about this stuff... that is why I was hoping someone with one of these cameras could actually measure the angle and post it with their lens length... still hoping!

Cheers,
Tom.

 

[tomhanman]

I should add that using the calculator

with a 1/3" sensor gives:2.8mm=81° 4mm=62° 6mm=44°

Using it with 1/2.5" gives: 1.8mm=92° 4mm=72° 6mm=51°

Which if you compare to those listings I've already found around the web... don't match any!! So I now have at least 5 sets of figures to chose from!!

 

[Kawboy12R]

Fun fun... With any luck someone who has one might be able to measure the angle or, failing that, have one facing a straight line like a curb at 90 degrees to their camera and then be able to measure the distance to the curb and the edges of the field of view at the curb and somebody else can do the math.

 

[Kawboy12R]

Why not give up on that cam and buy something with a varifocal lens? Or maybe buy two with the closest lenses to what you need and repurpose the "losing" camera to a suitable different location? Or tell your seller your exact requirements and let them do the measurement legwork with the guarantee that they will take it back if they're wrong. Buying the two closest fixed length lens cameras or a varifocal is probably the fastest and gets a camera mounted the quickest if that has any benefit to you. You will kick yourself if you needed the camera but didn't have one because you were trying to find the exact perfect field of view without spending a few extra dollars. I don't think I've ever regretted a purchase where I bought something a bit better with a few more features than I thought I needed as a bare minimum at the start.

 

[tomhanman]

If it was just the one camera, I would do exactly that. But I've got to cover a building I've just bought which big - I'm trying to plan the install of probably a dozen cameras. I will need a mix of lens lengths... and I thought that asking the question here I'd have a load of people with these cameras that could each tell me the FOV of their device, bob's your uncle. But no!

The seller is going to be chinese because I can't afford to to spend Europe prices... so asking them (as I did to start with) is just asking for trouble!

 

[Kawboy12R]

I hear you there. Some will say anything to get a purchase. Many aren't but it can be a bit of a dice roll.

 

[Razer]

Well, it is hard to give you information as while I own tons of 2.8mm, 4mm, and 12mm cameras I do not have numbers for the specific fields of view as far as my angles achieved. I know what to expect and can eyeball what I want easily enough. The other part is for me using 3mp cameras the FOV changes roughly 6 degrees when in 2mp mode vs being in 3mp mode. (can't do that on the 4mp though) I have 4mp 4mm cameras and 3mp 4mm cameras and they seem to be identical in shots achieved. I can tall no difference between the two looking at my resulting images.

Here is my best example I can share of a 2.8 mm lens in a camera set to the widest view. This is cropped, sorry, but you can still see that the camera is in the corner and is getting say 92 degrees of view or so by my estimate. 90 at least, but really just slightly better. No way is it 106. Looking at your numbers I would say your first set is the closest if I were to guess. Sorry for my weak sharing of photos but I just can't share what I'd like to!

 

[CamFan]

https://www.ipcamtalk.com/showthread.php/2759-Hikvision-focal-length-angle-of-view-and-other-lies?highlight=FOV+lies

I measured and calculated the angles and focal lengths. Found my 2.8mm focal length lenses to be closer to 3.2mm. Yeah, wtf?

My math and process is good here.

And forget about sensor size based calculators, hik never uses all of the sensor in any format.

 

[hiky]

just by chance yesterday i was told the 2.8mm 2342 at full res is 109 degs which seems about right

 

[CamFan]

just by chance yesterday i was told the 2.8mm 2342 at full res is 109 degs which seems about right

For a 2.8mm focal length lens to achieve 109° diagonal FOV, the sensor size must be 7.85mm diagonal (6.84mm wide x 3.85mm tall). This is 1/2.3" sized sensor.

I thought the HIK 4MP were Omnivision OV4689 1/3" sensors.

 

[hiky]

maybe 1/3" is easier to print than 1/2.3" ?? at full res it is a bit fisheye and almost appears to look behind itself at the edges but does not stream well, so i drop to 1080 to get a reliable stream with less fisheye

 

[tomhanman]

Razer, thanks for the pic. I appreciate that it is difficult to post shots. Could you confirm that this comes from a 2342 with 2.8mm lens? FOV is clearly over 90° but as the cam is heavily inclined towards the floor it is difficult to judge by how much.... but it seems to reinforce info I got very kindly from Hiky.

Many thanks for the comments Camfan. I love maths and process, and your work is impressive. But none of that gives me the real horizontal FOV for the DS-2CD2342WD-I. As we are talking about a product from China, I don't think it is worth the bother doing theoretical maths work... it may turn out to be more like conceptual maths work. I just want some simple visual truth!

Thanks for that extra suggestion Hiky... I'm going to refrain from adding that to the list of possibilities... or I will go mad!

I bought two 3332 cams a couple of years ago, and before choosing lenses I got the FOV details and calculated my requirements, and the cams corresponded perfectly, it was simple. For whatever reason for this cam things seem more complicated.

I will not give up.

 

[CamFan]

Well, no answers for sure.

China can't violate the laws of science. Focal length is focal length. Meaning, it cannot lie. Now if they stuff the camera with something other than 2.8mm lens, then you can't trust it.

Unfortunately, the photo is not doing us any favors. It's not perpendicular to anything. Can you mount it flat on the horizon and still see both walls?

If you get me still images from the camera, I can measure the real FOVs of a flat grid (I can send PDF to print out).

Or tell me with certainty which sensor the camera is using.

 

[tomhanman]

OK, I've given up and placed an order with a Chinese supplier for an NVR DS-7716NI-E4/16P one of each 2.8mm, 4mm and 6mm DS-2CD2342WD-I, and a single varifocal DS-2CD2642FWD-I. Delivery is 2-3 weeks. But when I get them I will be back with some reliable FOV angles... it might help someone somewhere.

For info, supplier is Hofotech. Prices are outstanding... will report back on the service and merchandise (if and) when I receive it!

 

[tomhanman]

Right, as promised, I am back.
DS-2CD2342WD-I International packaging and firmware, running in full 2688x1520 resolution Horizontal angle of view or FOV:
2.8mm = 105°
4mm = 81°
6mm = 55°

For anyone interested, I ordered my NVR and cams from Hofotech in China (sales15@hofotech.com guy called Cola). Good prices, good packaging, and all perfect international versions with no funny business! I will return to them to purchase the five or six other cameras I need, I suggest you give them a try - cheaper than all alibaba suppliers. That is all folks, hope this info helps someone.