A Wide-Angle Macro Lens With Electronic Focus, for Facial Capture
A UK animation studio needed a camera lens that sits just in front of a performer's face and captures every expression. We designed a compact wide-angle macro lens around a liquid lens, so focus is set electronically with no moving parts, then made and assembled it in Rye. Delivered in 8 weeks.
Close Enough to Be Comfortable, Wide Enough to See the Whole Face
In facial performance capture, a small camera sits in front of the performer's face to record their expressions. The closer the lens sits to the face, the more comfortable the rig is to wear, but the lens still has to see the whole face.
The customer also wanted focus to be set electronically rather than mechanically. The lens had to:
- Cover a 230mm tall field from just 150mm away
- Integrate a Corning Varioptic A-39N0-P04 liquid lens for electronic focus
- Fit an M12 mount on an IDS camera with 3.45µm pixels
- Hold MTF above 0.3 at 90 lp/mm across the whole field, from 425 to 650nm
The customer came with an initial idea: take an existing catalogue lens and tailor it to the application.
A custom design built around their camera and the liquid lens, with the field of view, working distance and image quality set for facial capture.
Building Electronic Focus Into a Compact Macro Lens
A liquid lens changes its optical power when a voltage is applied, so focus can be adjusted from software with no motors or moving parts. That keeps the head-mounted rig light and makes focus quick to set for each performer.
We designed the optics around the Corning A-39N0-P04 liquid lens and the customer's IDS camera, balancing a wide field of view against the short 150mm working distance, and holding the image quality to the pixel level of a 3.45µm sensor across the full field.
The result is a compact F/4 lens on a standard M12 mount, so it fits straight onto the camera.
Designed and Made in Rye
The optical design, the lenses, the metalwork and the final assembly were all carried out at our site in Rye, East Sussex, so the design was checked against what our machines can actually make.
- Optical designLens design and Monte Carlo tolerance analysis in Zemax.
- Lens manufactureEvery lens made on our CNC lens line in Rye.
- MetalworkLens housing and M12 mount machined on site.
- AssemblyLenses and liquid lens assembled and aligned in house.
How Image Quality Was Confirmed
Predicted in Design
A Monte Carlo tolerance analysis simulated many lenses built with random errors within our tolerances, confirming the design would hold its performance once made.
Focus Checked Across the Image
Focus was measured across the full width of the image in Rye.
Field of View Confirmed
The field of view was checked against the specification before delivery.
Accepted on the Customer's Software
The customer tested the lens in their own capture software and accepted it.
A compact macro lens with electronic focus that sees the whole face from 150mm, designed, made, assembled and delivered in 8 weeks.
Is an Off-the-Shelf Lens Not Quite Right?
Tell us about your camera and what you need to see. An engineer who works beside our production line will tell you whether a catalogue lens will do, or what a custom design would give you.
We reply within one working day. All projects can be handled under NDA.