How To Create A Custom Lens Specification

Your project has a killer idea, and you’re wondering how to turn it into a reality. Lens design projects start with the lens specification for the lens or optical system. These specifications are unique to lens design, so not all of them may be familiar to you. That’s OK! We are happy to discuss your needs so that you get a lens that does what you need it to do.

These are some of the tasks we commonly perform:

  • Specification of the optical system
  • Recommendation of the optimal type of optical system
  • Design of the optical system
  • Performance and tolerance reporting
  • Creating detailed drawings of the optical system including element drawings and mechanical parts
  • Prototyping the entire optical system, including glass and mechanical parts
  • Testing the optical system to make sure it meets your requirements

We prefer to contract for a fixed fee, based on the amount of time it will take to complete the design plus the cost of fabricating and testing the lens. If a project scope cannot be clearly defined up front, then we will consider working on a time and materials basis.

Here is a table of lens specifications that will define the design, with pictorial explanation below. Not all of the information may be necessary for your lens.

Magnification 0 for infinite object

Parameter Specification Comments
Application briefly describe how the lens will be used
Lens Type telecentric? zoom?
Iris (a) fixed, manual or motorized (shown in figure 1)
Focus fixed, manual or motorized
Lens Mount (b) C-mount, Nikon F-mount, Canon EF mount, PL mount, B4 mount, or custom (Shown in Figure 1)
Aperture image space f/# or object space NA
Magnification 0 for infinite object
Object Size (c) diagonal, diameter or angular subtense
Object Distance (d) from end of lens
Front Focal Distance (e) Distance from first lens surface to object (if object is at infinite distance)
Front Working Distance (f)  Describe anything between the object and the first surface of the lens, including cover glasses, filters, immersion oil, etc.
Total Conjugate Length (g)  distance from object to image
Barrel Length (h)  distance from front of lens to image
Back Focal Distance (I)  Distance from last lens surface to image sensor (if image is at a finite distance)
Back Working Distance (j) describe anything between the last surface of the lens and the image, including filters, cover glasses, etc.
Image Sensor (k) Brand and model number
Image Sensor Resolution Number of usable pixels
 Image Sensor Pixel Size  In microns
Resolution Performance  MTF (cycles/mm), spot size
Distortion  maximum, either percent or linear
CRA Control  Constraints on chief ray angle (Image/Object Telecentricity)
Peak Wavelength  nanometers or microns
Wavelength Range short & long or FWHM
Relative Illumination > 80% can be difficult; “no vignetting” is a good spec
Weight Any weight parameters that must be met

We can work through the above information together, or you may fill out and email a spreadsheet based on this template:  Lens Specification Sheet

Get Started!

If better optics would enhance your product, Eckhardt Optics will work with you to design and manufacture a custom tailored solution. Contact us or call for a consultation.