CIF vs D1

CIF and D1 represent different resolution standards in DVRs (Digital Video Recorders - they record analog cameras).

CIF DVRs have a 360 x 240 pixel resolution.

D1 DVRs have a 720 x 480 pixel resolution.

This means that D1 is roughly four the image quality level of CIF.Image quality can be very important and can be the difference between getting a blurry representation of someone and knowing exactly who it was. 

Our Econ line of DVRs record in CIF, while our Standard line records in D1.

CIF and D1 sample VIdeos

Make sure you click the white "four arrows" button near the SCW logo to see these videos in their proper resolution.

CIF Resolution
D1 Resolution

In case you didn't want to watch those video, here's an image from them.

CIF	D1

Why CIF and D1 aren't the only things that matter

Better Image Quality Does Not Always Mean Better Video Quality

Video Quality is dependent upon two things: image resolution and frames per second. Resolution improves image quality (which is why the videos above show a color swatch that doesn't move) while frame-rate improves video quality by preventing motion blur.

When purchasing a DVR it is always very important to also check the frame rate.Make sure it can record at 30 Frames Per Second (which is known as "realtime recording.")

Part of our 100% Satisfaction Guarantee is that All of our DVRs record at 30 FPS.

Buyer Beware: Some companies sell inferior "D1 DVRs"

Each DVR has a recording resolution and a live video resolution. D1 is currently the highest analog resolution used for both recording and live viewing, but many standalone DVRs are not able to record in D1 in realtime, which is 30 frames per second (fps). Because significant processing power is needed to record these high resolution images and it that much power wasn't available or economical then, D1 originally was not able to offer the same number of frames per second as CIF.

Nowadays with computing power being what it is, D1 DVRs can record at full 30 fps frame rates. However, some competitors obscure their frame rate by saying things like "FPS is 60" which makes their frame rate sound higher, however they often mean by that is "The Total FPS of all the cameras combined is 60." For example, if Total FPS is 60 than the frame rate is 15 per camera if there are 4 channels, or 7.5 FPS if there are 8 cameras.

Most people are unable to tell the difference between 30 FPS and above, so you don't have to go too much higher than 30 FPS, however, below 30 FPS can cause the video to be so "jerky" as to be unwatchable.

CIF and D1 aren't the only options

Nowadays, there are actually 4 resolution options for CCTV recording, but most DVRs can only handle CIF or D1. If you want HD recording, you will need to switch from analog cameras and a DVR to IP cameras (cameras with Internal Processors and which connect to a network and have IP addresses) and an NVR (Network Video Recorders - they record IP cameras).

IP cameras can record in 720p or 1080p (and also D1 and CIF).

Click here for a page similar to this one that compares 720p and 1080p resolution

The image below shows the relative size difference in image size (while keeping the pixel size constant) for CIF, D1, 720p, and 1080p. Each size increase is about 4 times as many pixels as the one before it. 

Note: your resolution won't prevent you from capturing a wide angle view, so you will be able to get a wide or narrow shot with any recording resolution. So, for example, you could record the whole scene below in CIF resolution, however, since it would only have as many pixels as are represented in the CIF area (360 x 240), it would be blurry.

 

How to decide if you need a CIF or D1 DVR

When purchasing a DVR, you should ask yourself if you need the higher resolution. If you do, you should ask if you need the frame rate to also stay at Full 30 FPS recording. Here's a flowchart of the CIF vs D1 decision making process, and here are some links to

CIF DVRs

D1 DVRs

Full D1 DVRs

www.truvision.co.uk