Why EX SDI cameras? digital, low latency, low bandwidth
Updated: Mar 19, 2020
EX SDI camera - Summary of benefits
1) EX SDI cameras make use of a signal that is digital, therefore
video quality level absolute (100%)
video signal is less prone to noise
video signal can be directly processed by an FPGA for image analysis, without ADC (analog to digital conversion) or other noise enhancing steps
2) EX SDI cameras have a video signal without (or hardly any) latency
3) EX SDI cameras have a video signal with lower bandwidth
allowing longer distances of signal transport if compared to HD SDI / 3G SDI /6G SDI
offering more flexibility in wiring
Industrial EX-SDI camera - Medical EX-SDI camera
skoopia offers more. Also operator productivity is fundamental in medical or industrial applications. Therefore, all skoopia EX SDI board cameras and skoopia EX SDI block cameras (often called EX SDI zoom blocks) support VISCA as a command protocol. Moreover, skoopia EX-SDI cameras have a very small form factor (e.g. 22mm x 26mm EX SDI camera 21C26S, see details below) making it very suitable to implement in space contained OEM camera products.
Finally, skoopia is well aware that a transfer from CVBS to EX SDI or even a transfer from regular SDI (HD SDI / 3G SDI / 6G SDI / 12G SDI) to EX SDI comes with questions from customers, adaptations and a legacy installed base. Therefore, all skoopia EX-SDI board cameras and all skoopia EX-SDI block cameras support CVBS and the regular SDI, minimizing the impact that comes with the transition.
skoopia ex sdi OEM cameras combine the advantages of ex sdi with the advantages of operator productivity and smooth transition from CVBS camera to EX SDI camera or from HD-SDI camera to EX-SDI camera.
EX SDI cameras introduction
skoopia markets several video outputs for cameras. Although skoopia market indsutrial IP cameras and medical IP cameras and skoopia has a wide range of industrial IP cameras in her portfolio, IP cameras have a significant latency, making them unsuitable for user / operator / medical doctor / surgeon assisted operation.
Comparison between different industrial cameras or medical cameras, all making use of compression enlarging efficiencies, Clinton Electronic, primarily active in the security camera business has made a very good video footage of the benefits of EX SDI cameras if compared to AHD cameras*, TVI cameras or CVI cameras.
* skoopia markets AHD cameras for settings in which EX SDI is not suitable or EX SDI is too cumbersome to implement. Nice to see in the "third party" video that although AHD cameras provide a lower quality compared to EX SDI caemras, it clearly outperformes (HD) TVI cameras and (HD) CVI cameras.
So, an EX SDI camera provides - alike 3G-SDI or HD-SDI cameras- the best image quality using regular coax. But EX SDI camera video output travels over longer distances. So what is EX SDI?
EX-SDI cameras or EX SDI cameras (sometimes written with sometimes without hyphen) stands for Extended Serial Digital Interface cameras. EX SDI cameras can transmit up to 4K - UHD - 2160p resolution for compressed video over coaxial cable.
Who is behind EX SDI camera technology?
Digital signal processor (DSP) chips supporting EX-SDI are developed and marketed by the South Korean company Eyenix.
Eyenix is a fabless DSP chip developer focused on high end industrial, medical and security applications.
To reach the compression Eyenix uses a technique called VLC (Visulally Lossless Codec). While latency of EX-SDI and HD-SDI/3G-SDI/6G-SDI is identical, the bandwidth of EX-SDI is lower.
video resolution 1080p30 1080p60 1440p30 2160p30
regular SDI HD-SDI 3G-SDI 3G-SDI 6G-SDI
bandwidth SDI 1.5 GHz 3 GHz 3 GHz 6 GHz
EX-SDI version v1.0 v1.0 v2.1 v2.1
bandwidth EX-SDI 250 MHz 500 MHz 500 MHz 1.5 GHz
Compression factor 6 6 6 4
Standard coax cable used for HD-SDI transmission (1.5 GHz) could therefore be used transferring 2160p30 (4K) video, as the frequency of the EX-SDI video signal has an identical bandwidth.
Eyenix has reported that EX-SDI 3.0 will support two output versions, a video output mode with a visually lossless (2160p30 at 1.5 GHz) signal and a video output mode with limited band width, but having visual losses (2160p30 at 250 MHz) in the video signal.
Visually lossless EX-SDI camera
Compression of video or images always generates a loss. Also EX-SDI cameras show a measureable loss in the video signal. However, this loss cannot be detected by the human eye.
The signal to noise ratio of contemporary cameras (skoopia sources source the best in world sensors from Sony (Sony Starvis Exmor R or Sony Preius Exmor R). Sony sensors provide a signal to noise ratio of approximately 43 dB, significantly better then old CVBS industrial cameras (typically at 38 dB). While these visual differences can clearly be observed, the difference between an EX-SDI video signal and an HD-SDI or 3G-SDI video signal coming from the same OEM camera (e.g. the industrial camera skoopia 128C42X or the skoopia 21C26S) can not be seen.
The compressed of the EX-SDI still has a signal to noise ratio of 56 dB, well above the 43 dB provided by worlds best sensors.. Effectively, only the identical noise level can be seen, not the image quality difference.
4K EX SDI camera
skoopia believes that the adoption of EX SDI is still at its infancy. Industrial and medical applications will continuously look for higher resolutions and/or longer/easier cabling distances. EX-SDI will be a suitable alternative. Particularly that one can upgrade from existing HD-SDI infrastructure to 4K-SDI without altering the cabling without any visual impact on the video appears extremely beneficial.
Video signal EX-SDI (MHz) S/N ratio (dB) Distance (m) HD-SDI (MHz) Distance (m)
1080p30 250 56 300 1500 80
2160p30 1500 56 80 6000 n.a.
2160p30 250 38 300 6000 n.a.
skoopia has released a blog on 4K EX-SDI camera for medical SDI applications, but also for industrial EX-SDI camera applications. Click here to read the blog. It's first medical 4K EX-SDI camera and industrial 4K EX-SDI camera has been released in December 2019.
EX SDI camera is digital.
EX SDI as a video output has the advantage of being digital. Although it has a higher bandwidth if compared with e.g. AHD cameras, the image quality is superior. Reasons are:
No video degradation over distance
Less susceptible to interference (electromagnetic noises)
The above two pictures show the impact of distance versus image quality. On the left you see the video quality gradually become worse over distance, which is very typical for any analog video transmission, such as video coming from AHD OEM cameras. On the right you see the video quality of a digital camera. Quality remains perfect up to the point that the signal cannot be transported, and the signal is lost. EX SDI board cameras or EX SDI block cameras will show such behavior (here 1000 foot, approximately 300 meter) implies that is is very likely a measurement made with an EX-SDI OEM camera, as HD-SDI or 3G SDI camera signals can typically not reach the described distances.
The above picture explains why analog video is more susceptible for noise, if compared to digital video. Whereas digital video is binary (0 and 1) in height and fixed in length of signal, the analogue video has different amplitudes as well as different length in time. Both make it more susceptible to noise, as can be seen in the pictures. Top is the signal without noise. Middle picture is the signal with noise. Last picture shows the difference between the original signal and the signal with noise. On the left is the analog signal. Ont he right is the digital signal.
Clinton Electronics, has made a great video to describe the benefits of Digital EX SDI cameras versus analog cameras (CVBS camera, AHD camera, TVI camera, CVI camera).
Back ground reading: SDI camera
SDI camera stands for Serial Digital Interface camera. At this very moment, SDI is vastly adopted in the medical and broadcast industry, and adoption in other industries is growing fast.
SDI as video signal has several sizable advantages over other digital transmission techniques.
Key advantages of SDI:
Low latency (alike CVBS)
Superb image quality as it is uncompressed
Plural options at the receiver side, SDI monitor, SDI grabber, SDI recorder
Support of Up the Coax - A smart cabling solution allowing power as well as camera control signals to use the same wires as the video transmission.
SDI has several frequencies providing different resolutions. Some resolutions have a specific name and are formally put into a standard by SMTPE, The Society of Motion Picture and TelevisionEngineers.
Bandwidths of SMTPE SDI cameras:
SD-SDI (480i60 or 576i50) - SDI as digital counterpart of CVBS (NTSC or PAL)
ED-SDI (480p60 or 576p50)
HD-SDI (1080i60 or 720p60)
6G-SDI (2160p30 or 1080p120)
24G-SDI (2160p120 or 4320p30)
Next to formal SMTPE standards numerous other resolutions and frequencies are available, and are often called identical names, such as:
HD-SDI (1080i50, 720p50, 1080p30, 1080p25)
6G-SDI (2160p25 or 1080p100)
24G-SDI (2160p100 or 4320p25)
Interestingly enough SDI is grouped on bandwidth, not on output resolution.
All skoopia SDI cameras support HD-SDI and 3G-SDI. All skoopia EX-SDI cameras, whether they are EX SDI board cameras or EX SDI block cameras, also support HD-SDI and 3G-SDI.
skoopia EX SDI cameras
This section describes skoopia's portfolio of industrial EX SDI cameras as well as medical EX SDI cameras.
SDI camera Dimensions Sensor
skoopia name l x b x h name Video output
board camera (1080p / Full HD)
21C26S 26mm x 22mm x 3mm IMX290 EX SDI, 3G/HD-SDI, CVBS
21C42S-LL 42mm x 42mm x 3mm IMX385 EX SDI, 3G/HD-SDI, CVBS
128C42X 42mm x 42mm x 3mm IMX226 EX SDI, 3G/HD-SDI, CVBS
block camera (1080p / Full HD)
20Z10S-NF 43mm x 44mm x 60mm MN3422 EX SDI, 3G/HD-SDI, CVBS 20Z30S 50mm x 60mm x 93mm MN3422 EX SDI, 3G/HD-SDI, CVBS
20Z30L 50mm x 60mm x 93mm MN3422 EX SDI, 3G/HD-SDI, CVBS
22Z36S-LL 54mm x 64mm x 128mm IMX385 EX SDI, 3G/HD-SDI, CVBS
block camera (1440p / Quad HD)
60Z36S-LL 54mm x 64mm x 128mm IMX178 EX-SDI, 3G/HD-SDI, CVBS
Short descriptions of each camera
Full HD, very small, single board 22mm x 26mm EX SDI camera | 21C26S
skoopia 21C26S is a unique camera. It is the first-in-class camera single board EX SDI camera having a board size of 22mm x 26mm providing Full HD output based, as well as CVBS. This EX- SDI camera provides HD-SDI, 3G-SDI and EX-SDI output, in paralle to CVBS, offfering Pelco-D in parallel to VISCA over UART 3.3V. EX SDI camera sensor is the Sony STarivs EXmor R IMX290.
Full HD, IMX385, single board 42mm x 42mm EX SDI camera | 21C42S-LL
skoopia 21C42S-LL is a single board EX- SDI camera (42mm x 42mm) providing Full HD output having the 1/1.8" super sensitive Sony Starvis Exmor R IMX385 sensor.
4K, EX-SDI, IMX226, single board (42mm x 42mm) | 128C42X
skoopia 128C42X is unique. It is the first camera world-wide that provides 4K SDI over regular coax. This is because it offers EX-SDI in 4K. It is based on the super senstive Sony IMX226.
Full HD 10x EX SDI block cameras | 20Z10S-NF & 21Z10L
skoopia has designed, engineered and produced two types of 10x optical zoom EX-SDI block cameras. 20Z10S-NF having EX-SDI, next to 3G -SDI, HD-SDI, AHD and CVBS output. 20Z10L having EX-SDI, LVDS and CVBS output.
skoopia markets the EX SDI block cameras as replacements for the obsolete Sony FCB-EX11 and Sony FCB-EV7100 series.
Full HD 30x EX SDI block cameras | 20Z30S & 20Z30L
EX SDI block camera 20Z30S has EX-SDI and TVI output, next to HD-SDI, 3G-SDI and CVBS meeting the exact dimensions of the Sony FCB-EV7500 series. EX-SDI block camera 20Z30L has identical dimensions, but supports -next to being an ideal EX-SDI zoom block - also LVDS and CVBS.
skoopia markets the EX SDI block cameras as replacements for the obsolete Sony FCB-EV7500 series.
Full HD / Quad HD 36x EX SDI block cameras | 22Z36S-LL & 60Z36S-LL
The EX SDI block camera 22Z36S-LL is a block camera with 36x optical zoom and super senstive sensor (IMX385). Alike the 22Z36S-LL, the 60Z36S-LL is also an EX SDI block camera with 36x optical zoom but offering Quad HD output (1440p30)
The EX SDI block camera 60Z36S-LL has the super sensitive sensor Sony IMX289 on board. It is a viable alternative in case you require higher resolution while keeping high optical zoom capability of 36x.
Both 36x EX-SDI block cameras offer EX SDI, 3G-SDI, HD-SDI and CVBS output. They are alos available as 36x EX-SDI block camera with EX-SDI, LVDS and CVBS output. The EX SDI block cameras are then called 22Z36L-LL respectively 60Z36L-LL