Is there a way of determining which lens you have?

[Jan J]

DS-2CD2042WD-I camera....
Is there a way of determining which lens you have, after it's installed? Can't seem to find anything in configurations...

I'm looking into buying some more of this version camera (Seeing that I seem to know the in's and out's of this particular camera)
and I now finding that there are different focal lengths available.

Since camera 2 will eventually want to live on side of garage, aiming back 100' or so toward the house, doing dual use: House security and Animal capture on the hill to right between house and garage.... I'm thinking I may want narrower angle... than what I have on house aiming toward pond.... But I'd like to determine what I have now, and pre determine what lens would be best for new camera location....

Is there a mathematical calculation of 'left to right field of view distance' compared to 'distance measured from camera' that will give me a ballpark idea of determining the lens I have now, and to pre calculate the field of vision from a potential camera position????
I would think that this would be a good tool.... but can't find that, either... So I post here!!!

Thanks...

P.S. I'm impressed with Sysnology NAS allowing Video Capture from Still only Camera, and also liking the two different Motion Detect settings: One set in Camera for Still Picture Motion, and differnent setting in Sysnology NAS for Video Motion.

 

[Phil]

Hi, unfortunately no, there's no indication apart from on the label on the box or the camera - which should state the focal length as well as the model number and serial number.

The 2042 mini-bullet was available with:
4mm - Horizontal field of view: 83°
6mm - Horizontal field of view: 55.4°

The free calculator at IPVM.com might help you to envisage the coverage:
IPVM Camera Calculator V3

 

[Jan J]

Thanks... Calculator won't load. FireFox 64 bit V63.0 was used
should be a mathematical way of determining lens is from field of view, distance to measurement and aspect ratio of image.

 

[Jan J]

See Next Post... This post does not contain enough information to be useful!!


I would think that if you knew the aspect ratio of the image you are looking at, and, the width of the image you see, and the distance between lens and width measurements, you should get a rough lens size....

Every "Calculator" I've seen wants the sensor size and or lens size..... Lens size is what I'm trying to get at!!
Or, Height and Width.... Heck, Height is un-necessary if you know aspect ratio and width of image you measure!

OR, if you have:
The 2042 mini-bullet was available with:
4mm - Horizontal field of view: 83°
6mm - Horizontal field of view: 55.4°

and are "X" feet from the measured object, I should be able to pre-determine from field of view in degrees, what the measured distance should be, and compare that with what I measure.. and find the unknown lens information from that!

Anybody know the calculations for this?

 

[Jan J]

I think I figured it out... Sensor of camera is 1/3"
Therefore:
with Y being 30', then X:
is 36' wide with 4MM Lens
is 24' wide with 6MM Lens

I measure ~43' Then I realize camera mounted above ground level... and hadn't calculated the camera's diagonal angle length... Recalculate with Y as 36' and then it matches!!
I have a 4MM lens!

I'll want a 6MM Lens for the next camera

Used this to calculate: CCTV Camera Lens Field of View Calculator