CCTV - analogue or digital

cestor

Active Member
Am I right that you effectively get the same result with an analogue PTZ camera that offers a sufficient level of optical zoom, as a high-resolution digital camera?
 
No.
 
An analog camera these days is limited by SD resolution (480) unless you go high end.  HD digital is just that.  (720, 1080 so forth and so on).
 
The bandwidth requirments are much lower with SD analog versus HD digital. As you move up the price scale on cams you get the best of both worlds relating to good optics and good electronics.
 
Personally here upgraded the optics on my analog cameras.  Its still an SD (480) view but a nice crispy picture.  The optical zoom picture is closer but its still 480.  The nicer digtial cameras offer both an optical and digital zoom; much like your digital SLR camera does today.
 
Read here:
 
http://trinitycctv.co.nz/cctv/analogue-versus-ip-cctv/analogue-versus-ip-camera-resolutions/
 
You can also integrate analog PTZ with an HD cameras.  The OS appears to include PTZ by default on my HD IP cameras.
 
But if you zoom in, then at SD resolution aren't you still getting equivalent or more detail than with an HD camera further away? Of course your analogue image is now restricted to a much smaller area because of the zoom.
 
Yes and no.
 
Apples and oranges difference.
 
The pixel resolution is different.
 
480 optical zoom provides you with a 480 defined pixel size.
1080 optical zoom provides you with a 1080 defined pixel size.
 
Test this with your digital TV set.  Watch 480 content and zoom in the picture doing the same with 1080 content.
 
Or go to best buy and do a side by side LCD comparison of a zoomed SD 480 picture next to a non zoomed HD 1080 picture.
 
The best cameras will have great optics (all glass) and auto/manual shutters similiar to an SLR on both an analog or digital camera.
 
Best to check out yourself.  Many vendors allow digital streaming to check out cameras which are analog with zoom or just digital HD.
 
This can't be answered.
 
An analog camera has only so many LOR and the zoom will only go so far optically...digital has so many pixels and when you blow the image up, the pixel size starts to affect the scene and you start getting "pixel bleed" where smaller objects at distance are distorted by the relative size of the pixels vs. the FOV. Very common on wide megapixel cameras. Great for getting a large image and being able to zoom in on smaller areas, but the detail starts to suffer.
 
As Pete said, apples to oranges (or more so, lettuce).
 
I recall once a few years back a misnomer (more than once) regarding the use of PTZ-DVR-NVR stuff where clients assumed that they could use PTZ - Zoom functions on recorded media.  This was related to couple of projects.  The original request was for a few outdoor analog PTZ with Zoom cameras all going to an NVR.  Basically because of issues 24/7 security was hired.  I did mention that if there were eyes on the cameras then yes you could utilize PTZ and optical zoom.  That said the misnomer related to using PTZ and Zoom on recorded media. 
 
With a situation like this though you could go to a megapixel IP HD camera (with higher than 1080 resolution) a bit wider optical lens and do digital zooming on the megapixel recorded media.  Thing was you have to record that and that itself would utilize much disk space.  Here though you are talking about a much more expensive endeavor both on the camera side and the NVR side; IE: big budget stuff.  A mixture of using a high end IP HD megapixel camera with both optical and digital zoom would fit here; but at a cost.
 
Yup.
 
You can do a "digital zoom" of the images at the cost of image quality; you're limited to what you have in resolution recorded.
 
With IP, if you have enough pixel density and are realistic with the size image you're attempting to see, yes you can enlarge after the fact, but the baseline image is going to be large.
 
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