2013 saw a growing trend towards smaller cameras.
As the cellphone industry has driven the development of smaller and more efficient image sensors, the surveillance industry has quickly latched on to the new technology. With multiple manufacturers releasing miniature cameras this year, I had to wonder: Is smaller really better?
Click here to view Figure 1.
As cellphone cameras continue to slowly replace point-and-shoots, consumer camera manufacturers are fleeing to higher ground. Nikon, Sony, and Canon have all begun releasing point-and-shoots with larger format image sensors. These new large-format point-and-shoots are typically heavier and bulkier than their predecessors but, in turn, offer near professional-level image quality, something cellphone cameras do not.
To understand why smaller image sensors result in lower image quality, one must first understand how image sensors capture light. Image sensors are made up of millions of light-sensitive spots called “photosites.” These photosites collect the light after it passes through the camera lens. The bigger the photosites, the more light can be captured.
Poor low-light performance
On smaller image sensors, these photosites are so tiny that they require an abundance of light in order to perform well. As light levels drop off, smaller image sensors are unable to collect enough light, creating images that are noisy and lack contrast.
Unfortunately, this problem will not soon be overcome. While image sensors may be getting smaller, the photons they collect will always remain the same.
Limiting lenses
With smaller image sensors come smaller lenses. These lenses are typically prime (or fixed) lenses and are usually of the wide-angle variety. Condensing so much information is a tricky job for these little lenses, and, consequently, image quality is often sacrificed. These tiny wide-angle lenses are prone to image quality issues like chromatic aberrations, loss of contrast, and vignetting. While vignetting might look impressive in an episode of Top Gear, it doesn’t have the same appeal in video surveillance.
Not all hope is lost though. Smaller image sensors do have their advantages. Aside from creating more discreet cameras, these sensors are extremely cost effective, as are the lenses that accompany them. With the added benefit, discreet megapixel cameras still perform significantly better than their analog counterparts. In addition, if you are one of those people who lie awake at night worrying about the polar ice caps, you will be happy to know smaller image sensors consume less energy.
Discreet cameras have their challenges. They will never boast the best image quality, and they are certainly not the right choice for every application. However, smaller cameras will always have a place in the surveillance industry, as long as that place is well lit.
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The trend in IFSEC over the last few years has been to make the cameras as small as possible, this article was interesting as the reduction in size has an impact on operational/output capacities.
For covert camera use or for areas where you don’t really have to worry about high resolution I can see the usefulness. For places like office areas where you don’t want larger cameras hanging from the ceilings I could appreciate a smaller footprint as long as the image quality is good when the lights are on. They might not replace every camera in every situation but I have yet to find a one size fits all camera in any format.
@Mike Clauss I agree with you. In my opinion size do matters but offcourse depending upon the situation it needs to be placed. I still feel we need to have tech where we get all the required functionalities and characteristics of a high resolution camera with as small size as possible. We might not be able to place big size cameras every where hanging down the ceiling. As you have pointed out we might compromise on few aspects but not on its main capabilities.
You’re right, Holmes. The topic of cameras going smaller has been covered extensively, and it’s refreshing and very informative to see a post that analyzes and discusses the impact of these reductions on performance.
A trade-off is definitely involved here, and it is up to the people in security to decide if they are worth making, given the limitations of smaller cameras while weighing down their benefits and advantages as well.
Good point, safeNsane. At this point, I don’t think there are one-size-fits-all cameras in existence yet that are of the size you want while being able to provide the features that you are looking for. You have to take each one and make considerations on a case to case basis.
I think it certainly depends upon the usage. We just cannot think or say that a standard device would serve a purpose for us. It’s just like we all wear various sorts of clothes and attach broaches with them. Till the time requirement is not adequately defined it would not be feasible to determine the sizes accordingly.
Another point here is that the much smaller cameras also use less expensive hardware so if you can put 3 or 4 of these in more strategic locations in the place of one higher resolution camera that is doing general duty they quickly start to make sense.
But while on the one hand some cameras have been getting smaller, and I think end users like this actually, there’s still some big cameras out there!
‘I have yet to find a one size fits all camera in any format.’ Hits the nail on the head doesn’t it really? But it’s certainly worth considering all the issues around surveillance ‘trends’ for the sake of a trend
Colin You comment that “While vignetting might look impressive in an episode of Top Gear, it doesn’t have the same appeal in video surveillance.” I have supplied a lot of HD minicams for use in Top Gear and I would say that they and the Broadcast Industry in general are a lot more critical of picture quality than anyone involved in CCTV. Vignetting, distortion and poor resolution at the edges and corners (Zones 2 & 3) are total no-no’s not to mention colour fringing and other light aberrations from poor quality glass. I do totally agree with your comment that there… Read more »
Small sensors can be made that do an excellent job. One company that does an excellent job of designing and manufacturing small sensors is Awaiba. Designed for chip-on-a-stick endoscopy, these small sensors, called Naneye, incorporate a thin chip lens and have an LVDS output. Unfortunately, the sensors used for the cellphone market and point and shoots are not of the quality used in endoscopy, military, scientific, or industrial applications. These are usually Grade 3 consumer sensors, with a lot of bad pixels, cross talk among the pixels, small dynamic range, and signal to noise ratio. To over come this, it… Read more »
How does one tackle the vendors of these poor quality ‘HD’ cameras with low-spec glass etc? A broadcaster is never going to be fooled, but a shop could. I suppose as you say it all comes down to price and reputation?
Is that as a result of multiple vendors forcing prices down over a number of years, do you think, or just securty being a traditionally hard-pressed budget?
I’d rather see several discreet cameras getting a more focused smaller area in detail than one, high up in one corner, seeing lots in detail but also potentially missing activity.
1) Image sensor optical format. Cell phones use tiny 1/7″ sensors, surviellance cameras use 1/4″ or, more commonly, 1/3″ sensors. Sometimes 1/2″. Why are surveillance sensors bigger? Because low-light sensitivty is a key spec for surveillance cameras, and the small sensors have teeny tiny pixels whose light-gathering capabilities are terrible. Great for filming Junior’s soccer game on a sun-drenched paddock, ineffective for seeing through the dark. 2) Lens focal length. Cell phones incorporate wide-angle plastic bubbles, surveillance cameras typically deliver much higher Modulation Transfer Function, a determinant of image quality. The surveillance lenses need to be larger. 3) Digital electronics.… Read more »
First point is spot on, something I think Colin agreed with right? These smaller form cameras are only ever going to approach useful in an extremely well-lit area.
Lighting is one of the big discriminators between surveillance and broadcast applications. In a broadcast studio, the lighting is carefully controlled, whereas surveillance applications demand both low-light sensitivity and wide dynamic range.
Impressive article and drives attention toward something that is not being examined as it should have been, I must say. Overwhelming desire and drive toward sleeker and smaller have often kept us from seeing what we are compromising for style and size. All these deficiencies of smaller cameras are relevant and worth considering for further scrutiny by security people.
@ safeNsane, it is very impressive indeed how you put sense into it. More than one small camera in strategic locations will also solve the problem of low light to some extent by recording from near the area. Besides, we never have enough cameras for better surveillance and face images, the more the better. As you have mentioned that cost will also not be a problem as these small lense cameras cost less.
‘More than one small camera in strategic locations will also solve the problem of low light to some extent by recording from near the area’
Will it? How so? Low light is low light?