Why shouldn’t I buy a $69 webcam for my machine vision application?

IDS uEeye camera

This is a question we get asked frequently: “Why should we pay $200 plus for your board level machine vision camera when we can just get a webcam for $69?”

A great question and maybe you can, but what ARE the differences?

Basically, there are just a few questions you need to answer to see if you should use a webcam for you machine vision application which are as follows:

  1. Do you need to program to integrate the video into an application with processing or control?
  2. Do you need consistent image quality?
  3. Are you doing computer vision (the computer is making decisions based on the images) or are you just viewing the images visually?
  4. Do you care if the camera specifications change over your product’s life cycle?
  5. Is the object under inspection moving?
  6. Do you need to control when you take the picture or interface to a trigger or strobe?
  7. Do you need to be able to choose what lens you will need?

If the answer to any of the above are YES, then a webcam will NOT work well or at all for your application. If the answers are NO, then by all means, you might be able to save money and just use a webcam. (You can stop reading here if you want, or continue for more details below).

Machine Vision Camera Software

Webcams do NOT come with a SDK as they are made to show video only. They normally provide a universal video driver, and also an application for viewing video.

Industrial cameras come with a SDK programmable in C/C++/C#/etc. It allows you to programmatically control the camera for both data acquisition and control of the camera’s parameters. (Example HERE to show extensive support of various operating systems and download)

Moving objects

Webcams have rolling shutter sensors which mean they cannot acquire images of moving objects without ‘smearing’ them. Industrial machine vision cameras use sensors with global shutters providing the ability to freeze the image to produce non smeared images of moving objects.

Example: Without adequate shutter speed with a global shutter, image will be blurry with motion

Trigger and Strobe Control

Webcams only have an interface to the USB data, whereas industrial machine vision cameras have hardware and software inputs and outputs. These allow for exact timing for a trigger to take a picture and a strobe to illuminate the object.

Example: External trigger control is tightly timed with IO including light flash. Courtesy of IDS Imaging

Camera Specs Changing over time

Webcams just need to show you video! In turn the manufacturers are not concerned if the sensors inside the camera change every six months. Whether the sensitivity changes by 10% makes no difference when you are just video conferencing with Grandma.

Industrial machine vision cameras are made with image sensors that don’t go obsolete every 6 months, but rather companies hope for 10 year life spans. It makes a huge difference if you are doing a computer vision algorithm that you have 5 man years of software development and the sensor’s sensitivity changes by even 1%.

Furthermore, the form factor of webcams change frequently as well. This doesn’t make a difference when it is just on your desk. It makes a huge difference when your camera and lens is fixtured in a machine that has 500 hours of CAD work to design, much less build. Moving the camera and lens 10cm might not be possible!

Do you need to choose your lens?

Webcams come with an integrated lens that is suitable for general viewing, and this lens is integrated with the camera and not changeable. Industrial machine vision cameras come with no lenses as not only do lenses come in a variety of focal lengths for different magnification, but also lenses coming in a variety of resolutions. Choosing a lens requires you to know the size of the sensor, your working distance, your field of view, and the pixel size. (See related educational blogs on lenses at end of this post)

What are your options for a low cost camera solution?

If you need industrial machine vision camera solutions with a solid SDK, long life cycles, at a low price, there several solutions to consider. Rolling shutter imagers are always lower price which are always a place to start along with USB2 interfaces. Read our previous blog HERE which outlines some specific models which are low cost. There is also a great new platform coming providing 5 Megapixel resolution with a rolling shutter imager, but with great performance for $280! Contact us for more details.

Click to contact
Give us some brief idea of your application and we will contact you to discuss camera options.

1st Vision’s sales engineers have over 100 years of combined experience to assist in your camera selection.  With a large portfolio of lenses, cables, NIC card and industrial computers, we can provide a full vision solution!

Ph:  978-474-0044  /  info@1stvision.com  / www.1stvision.com

Related Posts

Sony Pregius sensor “Generations” – What do those differences mean for machine vision?

Sony Pregius

Pregius
Courtesy of Sony
Machine Vision cameras continue to reap the benefits of the latest CMOS image sensor technology since Sony announced the discontinuation of CCD’s.  We have been testing and comparing various sensors over the years and have always come back to using Sony Pregius sensors when dynamic range and sensitivity is needed.

If you’ve been watching the technology shift from CCD’s to CMOS, you have probably also seen a ton of new image sensor names within the “Generations”.  Honestly, its hard to keep track of all of Sony’s part numbers, so we will try to give you some insight into the progression of Sony’s Pregius image sensors used in industrial machine vision cameras.

1 – First, how can I tell if its a Sony Pregius generation sensor?

Sony has prefixes of the image sensors which make it easy to identify if its an ExView HAD sensor or Pregius sensor.  Previous CCD, EXViewHAD sensors primarily in the last 10 years had a prefix of “ICX”.  Example:   ICX285, which was a great sensor back in the day.   All new Sony Pregius sensors have a prefix of “IMX”    Example:  IMX174.. which today is one of the best for dynamic range.
1stVision’s camera selector can be filter by “Resolution” and you can scroll and see the sensors with a prefix of IMX.  CLICK HERE NOW

2 – What is the differences in the “Generations” of Sony Pregius Image sensors?

Sony Pregius Generation 1:  This primarily consisted of a 2.4MP resolution sensor with 5.86um pixels BUT had a well depth (saturation capacity) of 30Ke- and still unique in this regard within the generations.   Sony also brought the new generations to the market with “slow” and “fast” versions of the sensors at two different price points.  In this case, the IMX174 and IMX249 were incorporated into industrial machine vision cameras providing two levels of performance.  Example being Dalsa Nano M1940 (52 fps)  using IMX174 vs Dalsa Nano M1920 (39 fps) using IMX249, but the IMX249 is 40% less in price.

Sony Pregius Generation 2:  The primary goal of Sony was to expand the portfolio of Pregius sensors which consists of VGA to 12 MP image sensors.  However, the pixel size decreased to 3.45um along with well depth to ~ 10Ke-, but noise also decreased!  The smaller pixels allowed smaller format lenses to be used saving overall system cost.   However this became more taxing on lens resolution being able to resolve the 3.45um pixels!   In general it offered a great family of image sensors and in turn an abundance of machine vision industrial cameras at lower cost than CCD’s with better performance.   

1stVision’s camera selector  can be filter by “Resolution” AND pixel size that correspond to one of the generations.  You will have a list of cameras in which you can select those starting with IMX!.  I.e  All Generation 2 sensors will be 3.45um, and can narrow to a desired resolution. CLICK HERE NOW

Sony Pregius Generation 3:  Sony’s has taken the best of both the Gen 1 and Gen 2 to create Gen 3!  The pixel size increased to 4.5um increasing the well depth to 20Ke-!  This generation has the fastest data rates, dynamic range and lowest noise.  The family will expand from VGA to 7.1MP as well.  We are just starting to see Gen 3 sensors in our machine vision camera lineup and expecting more to come through 2019+.

Contact us

Sony Pregius image sensor Comparison Chart

sony comparison chart

Sony’s Pregius Product line up for machine vision industrial cameras below for reference as of April 2019

Sony Pregius product line up
Courtesy of Sony

1st Vision’s sales engineers have over 100 years of combined experience to assist in your camera selection.  With a large portfolio of lenses, cables, NIC card and industrial computers, we can provide a full vision solution!

Contact us to help in the specification of your imaging components 

Ph:  978-474-0044  /  info@1stvision.com  / www.1stvision.com

How can we help answer your questions about industrial imaging?  We have used several terms you may not be familiar with and would like to help in your education.  Below are some related blogs that will help.  Or contact us via email or phone number as we love to help educate our customers!

Related Blogs & Technical resources

Imaging Quick ref Poster
Quick Reference Imaging poster download

What are the attributes to consider when selecting a camera and its performance?

CCD vs CMOS industrial cameras – Learn how CMOS image sensors excel over CCD!

Related Blog posts

Basic guidelines in selecting a machine vision camera interface

Machine Vision InterfacesIndustrial machine vision camera interfaces have continued to develop allowing cameras to transfer megapixel images at extremely high frame rates.  These advancements are opening up endless applications, however each interface has its own pro’s and con’s.

 

Selecting the best digital camera interface can be done by taking in several considerations first and in doing so, can window down your selection.

The following are some considerations in making an interface selection.

  1. Bandwidth (Resolution and frame rate)
  2. Cable Length
  3. Cost
  4. Complexity

Bandwidth:  This is one of the biggest factors in selecting an interface as it essentially is the size of the pipe to allow data to flow.  Bandwidth can be calculated by resolution x frame rate x bit depth.   You essentially find out pixels / second x the frame bit depth resulting in your total Megabits / second (Mb/sec).  Large frame sizes at high speeds will require a large data pipe!  If not, you’ll be bandwidth limited, so one would need to reduce the frame rate and image size or a combination of both.

Cable Length:  The application will dictate the distance between the camera and industrial computer.  In factory automation applications, the cameras can be located in most cases within meters from the computer vs a stadium sports analytics application requiring 100’s of meters.

Cost:  Budgets dictate in most cases, so this must also be considered.  Interfaces such as USB are very low cost versus a CoaxPress interface which will require a $2K frame grabber and more expensive cables.

Complexity:  Not all interfaces are plug and play and require more complex configuration.  If you are leaning towards interfaces using frame grabbers and have no vision experience, you may want to elect using a certified systems integrator.

The considerations above will start to dictate the interface for the machine vision application.  The chart below provides an overview to help in the selection process.  machine vision interface chartFor a PDF of this chart, please email jonc@1stvision with subject “Interface chart”

Digital machine vision camera interfaces.

The interfaces each have pro’s and con’s aside from the designated bandwidth, cable lengths and costs, and outlined as follows:

USB2.0 is an older standard for machine vision cameras and now superseded by USB3.0 / 3.1 .  Early on, this was popular allowing cameras to easily plug and play with standard USB ports.  This is still a great option for lower frame rate applications and comes with low cost.  Click here for USB2 cameras.

USB3.0 / 3.1  is the next revision of USB2.0 allowing high data rates, plug and play capabilities and is ratified by the AIA standards, being “USB3 Vision” compliant.  This allows plug and play with 3rd party software following the GENICAM standards.  Cables lengths are limited to 5 meters, but can be overcome with active and optical cables.   Click here for USB3 cameras

GigE Vision was introduced in 2006 and is a widely accepted standard following GENICAM standards.  This is a the most popular high bandwidth interface allowing plug and play capabilities and allowing long cable lengths.  Power Over Ethernet (PoE) will allow 1 cable to be used for data and power making a simpler installation.  GigE is still not was fast as USB3.0, but has benefits of 100 meter cable lengths.  Click here for GigE cameras.

5 GiGe (aka N-base T) & 10GigE similar to USB2 moving to USB3, is the next iteration of the GigEVision standard providing more bandwidth.   Both follow the same GigE Vision standards, but now at higher bandwidths.  Specific NIC cards will be required to handle the interface.  Click here for 5 GigE cameras. 

CoaxPress (CXP) is a relatively new standard released in 2010, supported by GENICAM, utilizing coax cable to transmit data, trigger signals and power using one cable..  It is a scaleable interface via additional coax cables supporting up to 25Gb/s (3125MB/s) and higher now with CXP12.  The interface can support extremely high bandwidth as seen in the above chart with long cable lengths to 100+ meters depending on the configuration.  This interface requires a frame grabber which adds cost and some complexity in the overall setup.  Click here for CoaxPress cameras

Camera link is a well established standard, dedicated machine vision standard released in 2000 allowing high speed communications between cameras and frame grabbers.  It includes provisions for data, communications, camera timing and real time signaling to the camera.  A frame grabber is required similar to CXP adding cost and some complexity and is limited in cable lengths to 10 meters.  Longer cable lengths can be achieved with active and fiber optic cable solutions which additionally add cost.   Click here for CameraLink cameras

CameraLink HS is a dedicated machine vision standard taking key aspects of CameraLink and expanding upon it with more features.  This is a scaleable high speed interface with reliable data transfer and long cable lengths up to 300+ meters with low cost fiber connections.  Similar to CXP and camera link a frame grabber is required adding cost.  Click here for Cameralink HS cameras

Some caveats:  In calculating bandwidth, you can calculate the theoretical data rate, but in some interfaces, the real world practical will be different.  In Camera link and CoaxPress, the theoretical and practical are the same.   In Cameralink HS, limits will be set by the computer interface (i.e PCIe x 8, Gen 3 is 6.8 Gigabyte / sec and an Xtium CHLS frame grabber can capture 7 Gigabyte / sec!)

The theoretical and practical limits for USB and Ethernet can be quite different and there will always be some difference.  For example, large frames and low frame rate generates less interrupts, providing less overhead to the CPU.   A small frame with high frame rate generates more interrupts causing more load to the CPU.

Click to contact As a note:  This blog post covers the basics of each of the interfaces.  There is much more information 1stVision can share with you to be sure you are taking all aspects of the vision application into consideration.  We have several additional resources we can share to help, so don’t hesitate to contact us for free consultation!

1st Vision’s sales engineers have over 100 years of combined experience to assist in your camera selection.  With a large portfolio of lenses, cables, NIC card and industrial computers, we can provide a full vision solution!

Ph:  978-474-0044  /  info@1stvision.com  / www.1stvision.com

Related Blogs

Learn about the new 5GigE camera interface

Learn about CoaXpress and frame rates achievable with Allied Vision’s “Bonito Pro” cameras with CXP-6

What is offered in a Machine Vision Industrial computer?

Learn about the new 5GigE camera interface

Dalsa Nano 5GigE

Machine vision interfaces have continued to evolve over the years increasing data throughput and cable lengths.  Commonly used interfaces are GigE and USB3.  However, 5GigE is an interface now gaining attention in the industrial imaging / machine vision market with some nice advantages.

We will outline the benefits of 5GigE, but first, lets give a brief overview of the commonly used camera interfaces, with their pluses and minuses:

GigE  / GigE Vision

  • 110 MB/s of sustainable throughput.  In real world terms, a HD, 2MP camera can get 50-55 fps in 8 bit mono or 8 bit color mode.  Note, this isn’t real HD, since you need 60 FPS.
  • Data cable lengths up to 100m using regular CAT 5e/6 cable.
  • Easy to put multiple cameras on a system.

USB 3 / USB3 Vision

  • 420 MB/s of data throughput.    A HD 2MP camera can run 60 fps in 8 bit mono or color and can  also run RGB at 60 FPS no problem.  With the higher throughput,  a 5MP camera can achieve 85 fps in 8 bit mode.
  • Data cables up to 5 meters and up to 20 meters with active cables. However, active cables can be quite costly, adding up to $200 in cost.
  • Not as easy as GigE to put multiple cameras on a system, and gets harder with each additional camera, especially if you have limited USB3 controllers.

As a note, there is no cost difference when using cameras with the same sensor from the same manufacturer with USB or GigE!  They will cost about the same with no premium for one interface over the other.

gige nano 5gigeWhat are the limitations of GigE and USB3 now solved by 5GigE?

  • USB3 is limited in cable length, so going faster than GigE is great, but you can not have long cable lengths.
  • GigE has cable lengths up to 100 meters, but is limited to ~ 110MB/s of data, so you do not have the high frame rates as in a USB3 camera.
  • USB3 in 4+ camera systems is not as stable as GigE AND you’re still limited on cable lengths.

Wait! – What about 10GigE? 

Up until now, 10G was the next interface. However, the jump to 10G has quite a few limitations as outlined below.

  • Heat generation is significant, so cameras are large and not in the smaller 29 x 29mm cube form factor.
  • Not a lot of demand for very high speed 10G, so not a lot of sensors being offered
  • Minimal number of manufacturers for 10G, higher cost.
  • Special cabling, either optical or high quality cat 7.

What we have found is that there are several types of applications for 10G cameras and are as follows

  • Applications where you need 10G of speed of course (high resolution + fast frame rates)
  • Require greater than  110MB/s of data and need long cable lengths.
  • Where there is the required combination of 110MB/s for high frame rates, multiple cameras and long cable lengths, 10G is a perfect solution.

We have seen that the need for higher bandwidth + long cable lengths is more prominent vs. the real need for 10GigE!

 Introducing 5GigE that provides increased bandwidth, long cable lengths at reasonable prices! or N Base T.5GigE machine vision applications

5GigE (also known as N Base T) has become a new standard for industrial, machine vision cameras.

In the general compute world, a much much larger market than vision, there has also been a need to go faster than GigE. However, the issue of replacing the existing cabling is the major issue preventing this. If you think of a big box store, say a Home Depot for instance, the amount of cabling is huge. Ripping that out and rewiring far exceeds the cost of the equipment to use it!

5G was made to go faster, but use existing cabling. Regular cat6e cable can be used, and 5G is a subset of 10G, so all switches etc. can be kept in service.

5G gives users in the vision market USB3 speeds, but with ALL of the regular GigE features, at a very small premium!

get quote1st Vision’s sales engineers have over 100 years of combined experience to assist in your camera selection.  With a large portfolio of lenses, cables, NIC card and industrial computers, we can provide a full vision solution!