Choosing the correct industrial camera for your system from the beginning can eliminate costly redesigns or upgrades in the future. The question is, how do you determine the best camera? Best is always subject to your needs. There are hundreds of options for just high-performance industrial camera, so where do you begin? We suggest a step-by-step approach that will hopefully help in the camera selection process to find the best candidate. Here is an outline of the approach we will expand upon further. By Adimec

1. How to Select the
Best Industrial
Camera

2. introduction
Choosing the correct industrial camera for your system from the beginning can
eliminate costly redesigns or upgrades in the future. The question is, how do
you determine the best camera? Best is always subject to your needs. There are
hundreds of options for just high-performance industrial camera, so where do you
begin?
We suggest a step-by-step approach that will hopefully help in the camera selection
process to find the best candidate. Here is an outline of the approach we will expand
upon further.
1.
Identify your key camera parameters
a.
b.
2.
Define the ideal camera
Prioritize your requirements
c.
Compare specifications of existing products
Preliminary camera selection
a.
b.
3.
Create list of possible products
More thorough comparison of specifications
c.
Look for references to get to develop short list
Camera Evaluation
a.
Look at an image
b.
Measure the Photon Transfer Curve
c.
Test within your system set-up
At the end of these steps, you should know what camera is the best for you. Of
course then you still have to determine if the company offers the right support and
manufacturing controls as well as consider pricing versus value. Or, if at the end of
this, you determine that none of the existing products will meet your needs, perhaps
some minor modifications will make for a perfect fit.

3. Step 1
Identify your Key Camera
Parameters
So to begin, here are some tips on how to identify the key camera parameters that are most
important to you. The best and most obvious place to start is at the end or in this case with
the properties of the required resulting image. You can describe your image-needs in terms
of:
Contrast
Contrast is the difference in brightness between the light and dark areas. It
may be negatively influenced due to reflections in the optics and or between
reflections between sensor and optics. For precise measurements these
reflections can be detrimental to accuracy. This relates to the dynamic
range (ratio of the maximum output signal to the dark level) and linearity (the
percentage deviation from the ideal response of an image sensor) of the
camera. In some applications it might lead to the requirement to have the
coverglass removed from the image sensor in the camera.
Resolution
Resolution is the sensor resolution in combination with the field of view (FOV)
that is being detected. It primarily defines the maximum spatial details that
can be captured. The equipment you are building in combination with the
measurement algorithm should give you numbers like pixels/object and objects
per image.
Sharpness
Sharpness is affected by the combination of image sensor and optics. If both
are not well matched, spatial details will be blurred.
Distortion
Distortion is an ‘error’ in the spatial representation of the 2D scene within the
image. The combination of image sensor and optics give rise to this artifact.

4. Noise
Noise can be shot noise at the sensor pixel level. At the image level view,
noise is related to capability of the camera to represent a 2D scene with a
certain uniformity. Non uniformity due to the camera is caused mainly by
offset & gain differences (e.g. noise) between pixels, and by pixel-, row- and/or
column defects. Extensive non-uniformity will limit the resolving capabilities
of the camera, especially when image sensor resolutions increase (e.g. multi
mega pixel field of views). When looking from image to image, it is the stability
of the camera that is seen as noise. An unstable behavior will limit the ability to
accurately capture subtle intensity variations between images. In other words,
a badly designed camera can ruin the images from good image sensors.
Define the ideal camera
After considering this how do you then
determine what camera you need? You want
all of these to be the best possible right? This
would mean a camera with the highest values
in many parameters such as those listed are
listed in the following list.
Important camera parameters
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Intra scene Dynamic Range
Detection Linearity
Pixel (shot) noise
Image Uniformity
Optical Reflections
Modulation Transfer Function (MTF)
Resolution within the Field Of View
Geometrical Distortion
Camera Stability
Sensitivity
Frame Speed
Smear (Sensor Capturing Principle)
Blooming
Prioritize your requirements
You can identify the ideal values for all of the above, and then accept that a camera meeting
all of those is likely not cost effective. It is therefore a good idea, to prioritize this list for the 5
most important parameters for you to achieve the image details you require.
First you can likely narrow down the basics of resolution, and frame speed necessary. Then
it can get a little harder. For example, determine whether your measurement is read noise
or shot noise limited. You should also consider the system requirements, such as what
kind of illumination you have to determine the actual sensitivity required or what optics will
be implemented. If you buy a high-performance camera and then an insufficient lens or
vice versus, you will not get the desired result. There is also which interface is preferred,
especially if the project is an upgrade of an existing system.

5. Compare specifications
of existing products
Now you are ready to search for products that match your key specifications. All of
the usual ways of internet research, trade show attendance, or phone calls to suppliers
should give you a good indication of what your options are.

6. Step 2
Preliminary Camera
Selection
Create a list of possible cameras with the
desired functionality
Suppose you have determined you need a lot of contrast in
your image which means you need a high dynamic range, and
your other system conditions have led you to conclude you
need 4 Megapixels with a frame rate of at least 150 frames
per second. The system is already based on the Camera
Link interface and because several images are used for
one measurement, you want global shutter technology to
minimize the image-to-image effects.
This can help you narrow down your search to cameras based on a specific sensor,
in this case say the CMOSIS CMV 4000. As you begin your search, you may find it difficult
to compare camera specifications as each supplier may have determine the values in a
different way or under different conditions even though they all use the same image sensor.
Another thing that is confusing is that cameras utilizing the same sensor can show different
values for several parameters, such as dynamic range.
Detailed comparison of cameras
For example, the Point Grey Gazelle GZL-CL-41C6, the Adimec QUARTZ Q-4A180, and
the Vieworks VC-4MC-M160 all utilize the CMOSIS CMV4000 image sensor. From readily
available and downloadable documentation from the manufacturers, you can find the
following:
Point Grey Gazelle GZL-CL-41C6
SNR 58 dB
Adimec QUARTZ Q-4A180m/CL
Dynamic Range 60 dB
Vieworks VC-4MC-M160
Dynamic Range 56 dB

7. These values can depend on the way in which the measurements were made, also Point
Grey presents the information as signal to noise ratio (SNR) rather than dynamic range. The
EMVA 1288 was developed to allow a consistent way of quantifying and comparing camera
parameters. Some camera manufacturers have had this analysis done by a third party or
have done it themselves and share the data. The cost for the analysis or equipment analysis
is somewhat high so some have developed their own methods. Even with comparable data,
you still need to know which exact value is required by your system.
Consult experts and references to narrow
down to 3 to 5 suppliers
Also, you may still have a relatively long list of potential options at this point. Perhaps this
list can be further narrowed down by asking either colleagues or industry professionals to
share their experiences (LinkedIn groups are a great resource). As the cameras are going to
be used in your systems, you may seek references and do some research on the stability and
consistency of the manufacturer in addition to individual camera performance.
Before camera evaluation starts . . .
Before you start ordering evaluation cameras and talking to camera vendors try creating a
checklist of items that are not camera properties but will affect the long-term buyer-supplier
relationship you will have. These include items such as support level, quality of service, longterm supplier, markets served, etc.
Once you have done this, you will likely have a shorter list of 3 -5 possibilities and now you
are ready to start evaluations.

8. Step 3
Camera Evaluation
and Final Selection
Even if you have consistent data from the camera manufacturers and strong
recommendations, you need to determine the necessary level of certain performance
parameters since there are sometimes price consequences for more stringent requirements.
Most industrial camera manufacturers have an evaluation/demo/loaner program to allow you
to borrow a camera and see for yourself. This process can require a lot of time which is why
it is so important to have previously minimized the number of possibilities.
Though the evaluation process is lengthy, it allows you to:
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See the actual hardware, the software, and the integration for yourself
Verify your assumptions
Verify the specifications provided
Check that it will enable the measurements you want to do
Look at the image
A good starting point is to simply get the camera up and running and look at the resulting
image. You can play around with the gain settings to get a feel for defect pixels or other
artifacts.
You may want to quantify performance
differences for yourself. The Photon Transfer
Curve (PTC) characterization method can be
used as a standardized test procedure to verify
performance such as read noise, dark current,
full well capacity, sensitivity, dynamic range,
LOG (Noise)
Measure the photon transfer Curve
SLOPE=1
SLOPE=1/2
SLOPE=0
gain, and linearity. A curve rather than one
data point can often give more insight if you
know how to interpret it. There are several
Full Well
Read Noise
Shot Noise
Fixed
Pattern Noise
LOG (Signal)
great sources on how complete a PTC calibration and calculate the camera parameters.

9. The links below are some other examples:
http://www.couriertronics.com/docs/notes/cameras_application_notes/Photon_Transfer_Curve_
Charactrization_Method.pdf
http://harvestimaging.com/blog/?p=784
Test within your system set-up
To truly understand which camera will be best, you may need to try them directly in your
system or at least in a test set-up, if possible.
At the end of these steps, you should know what camera is the best for you. Of course
then you still have to determine if the company offers the right support and manufacturing
controls as well as consider pricing versus value. Or, if at the end of this, you determine that
none of the existing products will meet your needs, perhaps some minor modifications will
make for a perfect fit. Then you need to find a manufacturer with a well-matched starting
product and the willingness and experience to tailor the camera.

10. adimec
Adimec specializes in the development and
manufacturing of high-performance cameras that meet
the application-specific requirements of key market
segments, including machine vision, medical imaging,
and outdoor imaging. Founded in 1992, the company
partners with major OEMs around the world to facilitate
the creation of industry-leading cameras.
The unique Adimec True Accurate Imaging® technology
provides new levels of precision and accuracy to vision
systems. Its diverse line of camera products meet a
wide range of performance, size, cost, interface and
application requirements. Adimec has offices around
the world focused on creating customer value and
satisfaction through local, personalized support.
Need more inspiration? Contact us www.adimec.com