Shutter vs Frame Rate

By: John Honovich, Published on Feb 27, 2013

Shutter speed and frame rate are frequently confused. They are certainly related and here's the key point - a camera's shutter speed can never be slower than its frame rate but it can be much faster. In this tutorial, we explain how, why and the practical implications of this.

Shutter Fundamentals

Shutter speed refers to how long the camera's sensor is exposed to light. It can be exposed for 1/10,000s or 1/100s or 1s, even more or less sometimes. If the shutter speed is 1/10,000s than it could open many times per second (30, 60, etc.). However, if the shutter speed is 1/2s, it can only do it twice at most. When you have very little light, you want to open the shutter for a long time (like 1/30s, 1/15s or even less). However, when it is very bright out, you want to open the shutter very briefly (like 1/1,000s or greater). See our shutter speed tutorial for more.

Frame Rate Impact

Each frame needs its own complete shutter. If you created 2 frames from the same shutter / exposure, the two would have the exact same input and would product the same picture, everything else being equal.

Imagine you had the camera set a 1s shutter. Could you do 30 frames per second?

No, unless you cheated. You could simply generate 30 copies of the same image from that single exposure. However, if you wanted to have 30 unique frames where each image differed from the previous, showing any motion / change, you would need 30 exposures in a second. To get those 30 exposures, the shutter speed has to be 1/30s.

Key Takeaways

  • If your shutter speed is slower than the frame rate, the 'true' frame rate must drop or the camera must insert copies of the same frame over and again. If you care about maintaining the frame rate, be careful about slow shutter. Not only may it cause blur but it will drop the effective frame rate. For example, many Axis cameras out of the box, drop to 6fps in low light because they are programmed to slow down to a 1/6s shutter speed.
  • When it is bright out, a camera's shutter speed will be far faster than the frame rate and the user does not need to do anything. The camera will make sure it works without intervention.
  • If you use a 60fps camera (becoming more widely available with new chip generations) and want to maintain that 24/7, the slowest exposure will now only be 1/60s, meaning that the amount of light captured in low light will drop by half compared to 30fps cameras.

 

Comments : PRO Members only. Login. or Join.

Related Reports

Bandwidth Fundamentals For Video Surveillance on Jan 13, 2020
Bandwidth is the most fundamental element of computer networking for video surveillance systems. Because video surveillance can consume an immense...
Startup Spectral Edge RGB+IR Claims "Unique Low Light Performance Tech" on Apr 03, 2019
This UK startup, born out of university research, is boldly proclaiming that they deliver "Unique low light performance tech for video surveillance...
Speco Ultra Intensifier Tested on Apr 22, 2019
While ISC West 2019 named Speco's Ultra Intensifier the best new "Video Surveillance Cameras IP", IPVM testing shows the camera suffers from...
Average Frame Rate Video Surveillance 2019 on May 23, 2019
What is the average frame rated used in video surveillance systems? In IPVM's 2011 statistics, the average was 6-8fps increasing to ~10fps in...
Smart CODEC Usage Statistics 2019 on Jun 03, 2019
Smart codecs are now nearly a standard feature in IP cameras, but our statistics show integrator adoption has not increased at the same rate. In...
False Verkada 'Unrivaled' Low Light Performance Claim Removed on Jun 12, 2019
Verkada falsely claimed that it delivered 'UNRIVALED LOW LIGHT PERFORMANCE' until IPVM questioned. In fact, Verkada's low light performance is...
Lens Iris Tutorial on Aug 08, 2019
Cameras, like humans, have irises, controlling the light which hits the imager and impacting image details. However, cameras have multiple types of...
Wide Dynamic Range (WDR) Guide on Oct 01, 2019
Understanding wide dynamic range (WDR) is critical to capturing high quality images in demanding conditions. However, with no real standards, any...
Biggest Low Light Problems 2019 on Nov 08, 2019
Over 150 integrators responded to our survey question: "What are the biggest problems you face getting good low-light images?" Inside, we share...
Budget Covert Cameras Tested on Nov 26, 2019
Covert cameras under $100 are widely available online but are they any good? To see how these models really work in the real world, we bought...

Most Recent Industry Reports

"Hikvision Football Arena" Lithuania Causes Controversy on Jan 24, 2020
Controversy has arisen in Lithuania over Hikvision becoming a soccer team's top sponsor and gaining naming rights to their arena, with one local MP...
Axis and Genetec Drop IFSEC 2020 on Jan 23, 2020
Two of the best-known video surveillance manufacturers are dropping IFSEC International 2020, joining Milestone who dropped IFSEC in 2019. The...
Multipoint Door Lock Tutorial on Jan 23, 2020
Despite widespread use, locked doors are notoriously weak at stopping entry, and thousands can be misspent on locks that leave doors quite...
Avigilon Shifts Cloud Strategy - Merges Blue and ACC on Jan 23, 2020
Avigilon is shifting its cloud strategy, phasing out its Blue web-managed surveillance platform as a stand-alone brand and merging it with its ACC...
Verkada Paying $100 For Referrals Just To Demo on Jan 22, 2020
Some companies pay for referrals when the referral becomes a customer. Verkada is taking it to the next level - paying $100 referrals fees simply...
Camera Analytics Shootout 2020 - Avigilon, Axis, Bosch, Dahua, Hanwha, Hikvision, Uniview, Vivotek on Jan 22, 2020
Analytics are hot again, thanks to a slew of AI-powered cameras, but whose analytics really work? And how do these new smart cameras compare to top...
Intersec 2020 Final Show Report on Jan 21, 2020
IPVM spent all 3 days at the Intersec 2020 show interviewing various companies and finding key trends. We cover: Middle East Enterprise...
Vehicle & Long Range Access Reader Tutorial on Jan 21, 2020
One of the classic challenges for access control are parking lots and garages, where the user's credential is far from the reader. With modern...
Clearview AI Alarm - NY Times Report Says "Might End Privacy" on Jan 20, 2020
Over the weekend, the NY Times released a report titled "The Secretive Company That Might End Privacy as We Know It" about a company named...
Favorite Camera Manufacturers 2020 on Jan 20, 2020
The past 2 years of US bans and sanctions have shaken the video surveillance industry but what impact would this have on integrators' favorite...