Category: Tutorial

Posted on

Macro Lens Vs Extension Tubes – What provides the best results?

Macro lenses solve the problem of imaging a small field of view from a relatively large distance away (relative to the size of the field of view). This solution normally consists of a large focal length lens, however these lenses have Minimum Object distance (MOD) and focus further away than desired.

For example: Using a 1/3” sensor, you want to look at a 3mm Field Of View (FOV) from 30mm away. The solution requires a 50mm lens, but 50mm lenses do not focus closer than 500mm away in some cases!
A solution is to add “extension tubes” in between the camera and the lens, but this leads to several problems like high image distortion, resolution loss (especially at the corners), poor depth of field and chromatic effects.  This makes this method not suitable for good imaging especially if accurate measurements are required.  

What’s the solution?
 
Opto Engineering Macro lenses!  These lenses are specifically designed for macro imaging allowing close up focusing and small field of views.  Unlike conventional lenses, these lenses are optimized to overcome image distortion, poor depth of field and chromatic effects.  A very low optical distortion makes these lenses perfectly suitable for precise dimensional measurement applications.  





As seen on the images to the right, using a macro lens delivers superior image quality compared to standard fixed focal length camera lenses using extension tubes.  











Incredibly low distortion is also provided by these macro lenses compared to standard fixed focal lenses with extension tubes.  These lenses will provide the same performance at the center and edges of the field of view.

This is crucial in flat measurement applications. 

Using conventional lenses, measurements will not be accurate and require calibration.  





Color consistency is provided by these macro lenses for demanding applications and corrected over the visible spectrum.  In turn, chromatic aberrations are not exhibited when compared to conventional lenses.  







Opto Engineering provides four series of lenses that cover 1/3″ to 2/3″ format area sensors and up to 63mm line scan sensors – Series as follows: 

  • MC Zero distortion macro lens (0.33  – 3X mag)
  • MC3-03X – Zero distortion, multi-configuration macro lens (0.1 – 3X mag)
  • MC4K  – Macro lenses for 4k linescan cameras (0.3 – 2X mag)  
  • MC12K – Macro lenses for 12k and 16k linescan cameras (0.07 – 2X mag)

Full Specifications can be found HERE.  

This short video provides a brief overview of the Opto Engineering Macro series lenses

1st Vision has extensive knowledge in industrial imaging and can help answer any questions.  We have over 100 years of combined knowledge and look forward to discussing your application.  

Please do not hesitate to Contact us for a quote. 1st Vision can provide a complete solution including cameras, lenses, lighting and cables.  


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

 
Follow us on Social Media!
    https://www.facebook.com/pages/1st-Vision/944658058935262?fref=ts           
Posted on

Teledyne Dalsa Turbodrive – GigE, Faster than GigE!

What is TurboDrive?

 

TurboDrive from Teledyne Dalsa, is a technology which enables cameras to transmit information at a rate exceeding the constraints of Gige Ethernet.  TurboDrive is a patent pending innovation that uses advanced data encoding techniques that look at the redundancy in the data coming out of the sensor. It uses image entropy based encoding to model pixel information with no loss of information. This enables faster data transmission on the link as each pixel is comprised of fewer bits for encoding.

 

Machine Vision cameras have traditionally used absolute encoding over 8 to 16 bits to transmit image information. For instance, in 8-bit, each pixel takes a value ranging from 0

(black) to 255 (white). TurboDrive relies on localized relative encoding to examine each pixel in its context before encoding it. This generates a more compact encoding of the pixel information and enables TurboDrive to be more efficient by packing the same information in less bits. 

 

 

What are the benefits of TurboDrive?

 

  • Faster frame rates than GigE (125 MB/s) by up to 235%, BUT using standard GigE networks. 
  • Eliminate the need for faster interfaces (i.e Base Camera Link @ 255 MB/s), saving costs and complexity especially on long cable runs. 
  • Allows aggregate information from multiple camera onto a single link.  For example, data coming from 2 cameras could be sent on same network card.
  • More efficient method of data packaging without any loss.       
  • Its essentially free with TeledyneDalsa cameras supporting TurboDrive 

 

Data sheets for all Teledyne Dalsa cameras with TurboDrive can be found HERE.  

 

Why you should be considering this technology?

 

Watch this short video to explain the technology in detail and how to speed up your systems over standard GigE networks.  

 

Seeing is believing!

 

In addition, we have a video showing Turbodrive in action.  We used the 2.3MP Nano-1940 camera, operating over a PoE network @ 80 fps which is ~ 150% over the GigE bandwidth!

1st Vision has extensive knowledge on Teledyne Dalsa cameras and can help answer any questions. 

Please do not hesitate to Contact us for a quote and to discuss your application!  1st Vision can provide a complete solution including lenses, cables and lighting.  

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

 
Follow us on Social Media!
    https://www.facebook.com/pages/1st-Vision/944658058935262?fref=ts           
Posted on

Battle of the Image Sensors – Sony IMX174 Vs CMOSIS CMV2000

 

Sony Pregius imaging sensors with a newly advanced pixel design provide unsurpassed high dynamic range, quantum efficiency and excellent signal to noise (SNR) ratios.  With a Dynamic range of 73 dB and a quantum efficiency of 76% (@ 525nm), this sensor will become a major work horse in the industrial imaging market.  Comparing these data points however can be mind boggling and leave you asking, “What’s the end result?” 1st Vision put the CMOSIS CMV2000 and new Sony Pregius IMX174 into the ring to battle it out!   
 
The old phrase of “A picture is worth a thousand words” definitely stands true in comparing sensors and reviewing images.  In our battle, we compared the CMOSIS CMV2000 (2MP CMOS)  sensor to the new Sony Pregius IMX174 (2.3MP CMOS) sensor.  We reviewed several of the key sensor aspects and are as follows. 
Specifications

From the specification standpoint, the IMX174 provides better values across the board.  (Refer to the SonyPregius Sensor page for detailed information on the terms)

   Comparison Data:


Round 1:  Saturation Capacity & Dynamic Range

Saturation Capacity or “well depth” is analogous to a bucket of water, however in lieu of water, we have electrons.  Given a larger bucket, we can pour more water in the bucket without it overflowing.  The water overflowing is analogous to “saturation”.  In turn, a sensor that has a larger saturation capacity (bigger bucket) can hold more electrons (water) without saturating (overflowing).  This would relate to the sensors overall dynamic range in that it will not saturate quickly in a given image, allowing us to see darker and lighter areas. 

The example below shows images comparing the CMV2000 and IMX174.  These were captured with the same lens, camera manufacturer and set at the identical exposures.  

Looking at these images, which one is the better sensor?  We would want to quickly say, “The brighter one!”, however brighter does not always mean better!

On the left CMOSIS image, we see a noticeable difference as it is starting to saturate especially on the lower right corner.  The colors are reaching peak levels in which they are close to saturating (brighter image).  For this given light level, our small “buckets” are getting full!

On the right IMX174 image, we can see similar brightness levels in the upper left corners, but the bottom right part of the image is NOT saturating, as well as the markers are not reaching peak values.  In essence, we have a small bucket with the CMV2000 and will overflow much faster than the larger bucket with the IMX174.  Relating back to our values in the chart, saturation capacity and dynamic range are much greater on the IMX174 and can be visibly seen in the images!  Sony Pregius wins round 1.

(Knowing this.. the brighter image does not always mean its a better sensor! )


Round 2:  Quantum Efficiency (Sensitivity)
In comparing the Quantum Efficiency values, we see the IMX174 is 13% higher.  This relates to the conversion of photons to electrons and in turn providing a higher numeric value in our image.  The images below were taken in very low light with a 10uS exposure.  The IMX174 provides a brighter image due to this added efficiency.



Sony Pregius IMX174 wins round 2 with a Knock Out!

The Sony Pregius pixel architecture is being expanded into many resolutions and will implemented into many industrial cameras.  

For a complete list of cameras with Sony Pregius sensors click HERE.  Keep an eye on this link as it continues to expand.  Need more technical information on the Sony Pregius sensors?  Click HERE

Contact us for a quote on cameras with the Sony Pregius sensors and to discuss your application!  1st Vision can provide a complete solution including lenses, cables and lighting.  

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

 
Follow us on Social Media!

 

    https://www.facebook.com/pages/1st-Vision/944658058935262?fref=ts           
Posted on

Imaging Basics – Calculating Lens Focal length

In any industrial imaging application, we have the task of selecting several main components to solve the problem at hand.  The first being an industrial camera and second,  a lens to acquire the given image.  In many cases, our working distance of our lens is constrained and may have to mount the camera closer or further from the object plane.  Once set, this defines our working distance (WD) for the lens.  In addition, we have a given field of view (basically the dimension across the image) of the desired object.  


In order to select the correct focal length lens which is denoted in millimeters (i.e 25mm focal length), we need additional information on the camera sensor.  Camera sensors come in various “Image formats”.  The chart below indicates some common formats which relate to the sensor size.  The sensor size can be found on the actual sensor datasheets if not available in a given chart.  


For this exercise, we want to image an object that is 400mm from the front of the lens to the object and desire a field of view of 90mm.  

We have selected a camera with the Sony Pregius CMOS IMX174 sensor.  This uses a 1/1.2″ format which measures 10.67mm x 8mm.  


We have the following known values at this point: 

Field of View (FOV)  =  90mm
Working Distance (WD) = 400mm   
Sensor Size = 10.67mm – We will calculate for a 90mm horizonal FOV, in turn use the horizontal sensor dimension

The basic formula on how to calculate the lens focal length is as follows:

FL = (Sensor size * WD) / FOV

Using the values from our application, 

FL = ( 10.67mm * 400mm ) / 90mm 
FL = 47.4mm

Lenses are only available off the shelf in various focal lengths (i.e 25mm, 35mm, 50mm), so this calculate is theoretical and may need an iteration to adjust working distance. Alternatively, if your application can have a slightly smaller or larger FOV, the closest focal length lens to your calculation may be suitable.


1st Vision has made calculating your lens focal length a bit easier!  As in engineering, its good to know the background formulas, but in practicality, like to simplify life with tools

You will find our lens calculator HERE.  Alternatively as select a camera, you will find an icon to the right which will automatically populate the calculator.  Below is a short video showing how to use this resource from the camera pages.  





A few additional considerations when selecting a lens:

  • Lenses have minimum working distances (MOD), so this should be considered when reviewing a lens setup.  MOD’s can be found on the lens page for the given lenses.
  • Lenses need to be paired with the appropriate sensor.  For example, if you have a 1/2″ sensor, you need to ensure you are using a 1/2″ format lens or larger.
  • In selecting a lens, you need to ensure the lens has enough resolution (in lp/mm) to resolve the pixels on your camera.  Be sure to review this data carefully once you ID the desired focal length.  Demystifying lens specifications provides further understanding. 


Related Blogs: 
Demystifying Lens Specifications
Understanding Lens MTF
Calculating Resolution for Machine vision


Contact us to discuss your application and help make a recommendation!  1st Vision can provide a complete solution including lenses, cables and lighting. 

www.1stvision.com  
Ph:  978-474-0044

Do not forget to follow us on social media!
    https://www.facebook.com/pages/1st-Vision/944658058935262?fref=ts