SD Cards: The Unsung Heroes of Video Surveillance

Uri Guterman

Uri Guterman

SD cards are small and tucked away, but we should never take them for granted as they can make a significant contribution towards end users achieving maximum benefit from their video surveillance systems. Here, Uri Guterman sings the praises of SD cards and provides some particularly useful guidelines on what to look out for when buying them.

SD cards are supplied in various formats for you to choose from, although your decision will obviously be affected by what your cameras’ memory slots are capable of accommodating. The good news here is that many of today’s HD IP cameras have slots which provide the option to use most – if not all – of the available SD card formats.

Why, though, are SD cards so important? The migration from analogue to IP network-based video surveillance solutions has created a common scenario whereby the recording and storing of images can be quite remote from a camera’s location. SD cards will help to keep data safe in the event of network disruption.

In this respect, if you want to avoid any gaps in what may be crucial video evidence, it’s recommended that, before buying, you take a close look at a camera’s specifications to check it has an Auto Recovery Back-Up. This feature will ensure that any activity recorded on the SD card during network disruption is automatically transmitted to the remote recording device when network service is eventually restored.

Edge-based applications

The massive processing power of the chipsets at the heart of the latest generation of HD open platform cameras provides the opportunity to run multiple on-board third party analytics applications such as ANPR, heat mapping and people counting in the same way apps are used on smart phones. These elevate video surveillance from just being a security system which assists in monitoring and detecting suspicious activity to a smart solution delivering so much more.

The data captured by these applications can be recorded on SD cards and remotely downloaded for analysis as and when required. End users should look out for cameras which have dual SD memory card slots. These will provide you with greater storage capacity, as well as the option to use one SD card for edge-based applications and the other for recording images.

Matters of capacity

I suspect there may be many end users who hold the perception that SD cards, including those which are capable of storing up to 256 GB of data, are too limiting in terms of how much information or video that can hold. While they’re not intended to negate the need for a Network Video Recorder, SD cards should have more than enough capacity to store the short term demands caused by network disruption and record analytics data, or perhaps store images which have been captured as a result of the triggering of a camera’s motion detection function.

Equally important, an SD card write speed should be taken into consideration. The large file sizes of images captured by Full-HD and ultra HD 4K cameras dictates that it would be wise to specify a Class 10 SD card that’s capable of write speeds of 100 Mbps. These are on offer from most of the well-known SD card manufacturers, such as SanDisk, who will also provide you with peace of mind in terms of quality and reliability.

The options available to today’s end users? SD: Up to 2 GB. SDHC: 4 GB to 32 GB. 3DXC: 32 GB to 2 TB.

Whatever you’re hoping to achieve from a video surveillance system, make sure you populate the SD card slots before the cameras are commissioned. Leave it until it’s too late and you might just miss out on recording some critical data.

Uri Guterman is Head of Product and Marketing at Hanwha Techwin Europe   

*Do you have some questions about SD cards to which you need answers? If so, e-mail Uri Guterman at

About the Author
Brian Sims BA (Hons) Hon FSyI, Editor, Risk UK (Pro-Activ Publications) Beginning his career in professional journalism at The Builder Group in March 1992, Brian was appointed Editor of Security Management Today in November 2000 having spent eight years in engineering journalism across two titles: Building Services Journal and Light & Lighting. In 2005, Brian received the BSIA Chairman’s Award for Promoting The Security Industry and, a year later, the Skills for Security Special Award for an Outstanding Contribution to the Security Business Sector. In 2008, Brian was The Security Institute’s nomination for the Association of Security Consultants’ highly prestigious Imbert Prize and, in 2013, was a nominated finalist for the Institute's George van Schalkwyk Award. An Honorary Fellow of The Security Institute, Brian serves as a Judge for the BSIA’s Security Personnel of the Year Awards and the Securitas Good Customer Award. Between 2008 and 2014, Brian pioneered the use of digital media across the security sector, including webinars and Audio Shows. Brian’s actively involved in 50-plus security groups on LinkedIn and hosts the popular Risk UK Twitter site. Brian is a frequent speaker on the conference circuit. He has organised and chaired conference programmes for both IFSEC International and ASIS International and has been published in the national media. Brian was appointed Editor of Risk UK at Pro-Activ Publications in July 2014 and as Editor of The Paper (Pro-Activ Publications' dedicated business newspaper for security professionals) in September 2015. Brian was appointed Editor of Risk Xtra at Pro-Activ Publications in May 2018.

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