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How to select the best industrial camera, Step 3 Camera Evaluation and Final Selection

Posted by Gretchen Alper on Thu, Jan 26, 2012

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. 

In our previous blog post we talked about searching for available products and then narrowing down your possibilities to a short list of 3 to 5 camera suppliers. 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:

  • 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

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, 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 great sources on how complete a PTC calibration and calculate the camera parameters.  The links below are some other examples:

Photon transfer curve

Source of image is the document in the following link.

http://www.couriertronics.com/docs/notes/cameras_application_notes/Photon_Transfer_Curve_Charactrization_Method.pdf

http://harvestimaging.com/blog/?p=784

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.

Download the whole series in 1 document!  Click the image below - no contact information required.

how to select the best machine vision camera

Topics: Vision System Optimization

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