Optical and digital zoom can be used in a variety of applications from photography to graphic design to security cameras. In this brief tutorial, we explain the concepts of optical zoom versus digital zoom as related to security cameras during common uses like live observation or forensic investigation after an incident has occurred.
In this video and article, we are exploring optical and digital zoom as related to security cameras. And even in the security camera field, there are various applications as well such as when watching live video, using recorded footage, setting up a fixed camera with a varifocal lens or even using a pan-tilt-zoom (PTZ) camera in live, or real-time, mode. So, be sure to consult with our team or your security partner for more details as related to the device or software you will be using.
In the first sequence, we see Matt walking closer and closer to the object he wishes to see in more detail, in this case, a license plate. The lens in his eye has no way to optically or digitally zoom in on the object of interest, so he has to physically walk closer to see more details of the license plate.
In the second sequence, we are adjusting the camera’s physical lens to zoom in on the object during installation of the camera, just as you would with a DSLR camera lens for taking pictures. This security camera has a varifocal, or manually adjustable, lens range of 4.4 millimeters at it’s widest setting to 10 millimeters at its most telephoto, or zoomed in, setting. This means that within that range, you are seeing the image at maximum resolution of the camera. NOTE: This is where DORI considerations are most important to have been considered prior to purchasing and installing your security camera. See the information below about DORI.
In the third sequence, we are using Bosch Video Management Software (BVMS) to digitally zoom in on the object after it has been recorded. This means that we are zooming in on the pixels of the recorded video footage. As a result, with each increase in digital zoom, we are seeing an image that is more and more pixelated or blurry. Digital zoom may be required when the object you are trying to see is still too far away when using the maximum optical zoom of the camera’s lens. This is often helpful during forensic investigations when the object or person in question is simply too far away from the camera to gather the forensic evidence required from the recorded video footage.
Most pan-tilt-zoom cameras provide the operator the ability to optimally zoom in and out as an area is observed. If necessary, the operator can usually zoom in digitally in live mode once the optical range limit has been met.
Do you know DORI?
We have created an article and video explaining the concept of DORI which explains the reasons to select the proper lens for the desired camera task. Simply put, do you wish to DETECT that someone or something is present, do you wish to OBSERVE something in particular, do you desire to RECOGNIZE someone you’re already familiar with coming through a doorway, or do you wish to IDENTIFY someone or read a license plate in recorded footage with certainty.
Click here to access the DORI article and video >>
We hope this has been helpful.
You can always contact us at, support@midches.com
