Considerations in selecting a lens for a large format camera sensor

For most cameras in the automated imaging marketplace, the sensor sizes are 1” and less. (1″  sensors have 16mm image circle/diameters)

Note the size in inches and the image circle size in millimeters do NOT match!  1” does not convert to 16mm!.  But that is a topic for another blog post!)

Industrial cameras with C/CS mount sensors normally range from ¼” to 4/3” ( up to 22mm image circle, which is the largest a C mount is by definition).

However, there are many cameras that have sensors larger than this, with many being a full 35mm sensor.  These sensors typically require larger F or EF mounts as seen in the picture above.

Click here for F-mount lenses from Kowa

Click here for F-mount lenses from Schneider

The question becomes, how do you find a suitable lens for these cameras?

First, let address the Issues with F mount lenses

The mount most commonly used by camera vendors for sensors larger than C mount are F mounts.  F mounts are most popular mount for SLR cameras, designed by Nikon about 1960. https://en.wikipedia.org/wiki/Nikon_F-mount

F mount lenses for commercial and consumer/prosumer cameras are excellent optically and priced well but there are several issues you need to consider with these lenses for automated imaging applications.

  1. First, F mount lenses are bayonet, not screw mount. That means they are not as secure as C mount, and therefore, much more prone to vibration, or even coming lose.
  2. F mount lenses for the consumer/prosumer market are designed to take fantastic color pictures. To do this, the lens coatings are optimized for color. This can affect mono images.
  3. Consumers want their cameras to be light, so the F mount lenses are made with as much plastic as possible. This is not great for industrial applications
  4. These lenses are designed for automatic focus and exposure and have controls for that in the lens itself.
  5. Finally, the last issue is that many of these lenses are designed for the automated controls with prosumer cameras, autofocus and autoexposure.

If you can find an all metal manual F mount lens from 20 to 30 years ago, it would be great for an industrial application!  If not, we suggest you turn to one of the companies that make F mount lenses specifically for this market. The major vendors are Schneider, Edmund Optics, and Kowa.  All have a series of F mount lenses that are much more rugged than a prosumer F mount lens, and also don’t have the extra controls for automatic focus/iris.  They have lock screws as well to hold their settings.  The major limitation to these lenses are that they cost more than prosumer lenses, and are in just a small range of focal lengths.

Contact us for further specifications and pricing

EF Lenses

Since many of the new large format lenses can be controlled electronically via the camera, the automated imaging industry has created several products to use these lenses. The solutions from Birger Engineering, www.birger.com are straightforward to use. They make a mount that attaches to the  camera and allows for the use of EF mount lenses.  Attached to their mount are connections to drive the lenses, via serial commands with their SW.  Several camera manufacturers have built cameras with EF mounts as part of the camera.  This is an especially nice solution since there are no wires hanging out for control, and the lens is controlled directly from the camera’s SDK.

This provides a high level overview of the considerations in selecting a lens and size for large format camera sensors.  1st Vision has extensive knowledge with lenses and cameras and will help you in the selection process.

Please contact us and discuss your application with our sales engineer! 

Related Blog posts:

Canon EF mount integrated into Allied Visions GT1930L

Imaging Basics – Calculating lens focal lengths

Not all lenses are created equal!

10 key things you need to know when selecting a machine vision lens

Improper selection of the correct quality and type of machine vision lens can make your camera selection useless!

In many cases, we see customers attempting to choose a low quality lens for a camera that really needs quality optics to resolve the pixel sizes. Conversely, we also see customers trying to over specify a lens, where you simply need a lens that’s “good enough”


1st Vision has a white paper to help in the lens selection and provide valuable knowledge on various topics to make the best decisions. 

In this comprehensive white paper, you’ll learn the following

  1. Background basics on lenses and what they really do!
  2. The science in some basic formulas to calculate MAG, focal length and angular FOV
  3. What are extension rings used for?
  4. How are lenses rated?  MTF explained
  5. The myth behind “Megapixel” lens ratings
  6. How many pixels do I really need?
  7. What is the ” f# ” of a lens
  8. What does the “lens format” mean?
  9. Comparison of lens types from security to Factory Automation (FA)
  10. How to get some practical advice!

Download the White Paper

1st Vision has many other resources in our educational blogs.  Please find related links to lenses below.  

We are happy to discuss your imaging application in details  Just contact us!

Links:

Learn about FUJI’s HF-XA-5M (5 Megapixel) lens series which resolves 3.45um pixel pitch sensors! Perfect for cameras with Sony Pregius image sensors.

 

FUJINON has continued to expand its HF-XA-5M product line with the new 5 MegaPixel lens (MP) series.

These lenses provide the resolving power required for the popular Sony Pregius Image sensors with 2/3″ formats and 3.45um pixel pitch.  

For any cameras using the Sony Pregius 5 MP IMX264 and IMX250 sensors, these are a perfect match for the pixel pitch.  Even older   Sony ICX625 sensors will benefit from the new HF-XA-5M lenses.  




FUJI HF-XA-5M Unique Features  


Compact design for installation versatility

The FUJINON HF6XA-5M, with a focal length of 6mm measures just 39mm in external diameter, the world’s smallest machine vision lenses of this class. The other five models are also compactly designed with the external diameter of 29.5mm, which is about the same size as general compact machine vision cameras. The entire series contributes to achieving a compact form factor for machine vision systems
 
Advanced Optical performance 

FUJI’s unique “4D” High Resolution performance delivers edge to edge sharpness under a range of installation conditions

Delivering high resolution of 3.45 µm pixel pitch on a 2/3-inch sensor at the working distance of 50cm, which is the most frequently-used distance among users.
The unique “4D High Resolution” function mitigates resolution degradation when changing a working distance or aperture value. It maintains their high resolving power of no less than 4.4 µm pixel pitch (equivalent to 3 megapixels) on a 2/3-inch sensor from the image center to all corners. This function perfectly matches when you want to set the aperture wide open to achieve a faster shutter speed.
 
 
Designed for installation convenience
 
Three screw holes each are provided on the iris ring (aperture) and the focus ring. Users can choose the optimum hole according to their installation conditions, providing a high level of installation convenience.
 



 
 
 
 
 
  
Please do not hesitate to Contact us to discuss your application and help select a lens.    1st Vision can provide a complete solution including cameras, lenses, lighting and cables.  We have over 100 years of combined experience we can put to work for you.  

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

New High Resolution 1.1” Lenses are a perfect fit for the new Sony 1.1” 12 MP Sensor cameras

Sony’s Pregius image sensor line has continued to expand to higher resolutions and sizes.

The latest 12 megapixel, Pregius IMX304 sensor has a 3.45um pixel pitch which requires a 1.1″ lens to prevent vignetting.

In order to obtain optimal contrast within an image using this sensor,  a lens supporting at least 145 line pairs / mm must be used.

 


The lenses are optimized for down to 3.1um pixel pitch images.  Use of state of the art optical technology enables high contrast and high resolution from the center to edges of the lens, despite the large lens aperture.   

Examples below






The image to the left demonstrates improper pairing of a lens without enough performance to adequately resolve the size of the pixels on the camera.  Zooming into the given areas shows lack of contrast

 

 

The image to the right demonstrates the performance of the Tamron 1.1″ lens on the new 12MP, 3.45um pixel pitch image sensors.  Zooming into the given areas show high contrast in the center and edges of the lens.




Alternative solutions prior to now would be to use a 4/3″ or F-mount lens which are very expensive.  If a 1″ format was used, you will have vignetting on 5% of the edges of the lens. This lens is the best solution for the larger 1.1″ sensors!

Key Features include

  • Compatible up to 1.1″ C-mount cameras:  Compatible with image sensors up to 1.1″ formats and image circle diameters of 17.4mm (effective image circle diameter to 17.6mm).  
  • Industrial leading high contrast and resolution:  Compatible with 3.1um pixel pitch image sensors, up to 1.1″ sensors.  Perfect for Sony Pregius IMX304, 12 megapixel sensors.
  • Lens designed for High-Fidelity imaging:  Uniform high contrast and resolution from the corners to the center despite the large aperture size.  Provides 160 lp/mm in the centers.  
  • Combination of advanced coating technology:  Integration of advanced techniques such as broad band anti-reflection coatings are used, additionally allowing for high image quality at close distances. 
  • Enhanced Functionality and Utility:  Well tuned rotation torque of both focus and iris control rings facilities smooth adjustments.  Lock mechanisms on the rings can be positioned at a choice of tree lock positions.   

 

 

Interested in cameras using the new 
Sony Pregius IMX304 12 Megapixel image sensor?  


A list of current cameras with this sensor are below: 

Allied Vision cameras
Manta G-1236 – GigE, 4112 x 3008, 9.7 fps, 

Teledyne Dalsa cameras
Genie Nano M4020 / C4020  (Coming soon!)