Infinity Corrected Microscope Design
Traditional Microscope system Traditional microscope systems consist of two main optical elements: a microscope objective and an eyepiece. The microscope objective is placed close to the sample that we want analyzed. The distance between the objective lens and sample is called the working distance and depends on the magnification of the objective lens. The objective […]
Non-sequential ray tracing
When doing optical simulations using a program like ZEMAX, we can choose to do our simulations using two modes: sequential and non-sequential optics. Sequential optics, as the name indicates, follows the optical path of light as it goes from one surface to the next. For example in Cooke Triplet shown in Figure 1, light travels […]
Rigid Endoscope Design
Endoscopes are medical devices designed to collect the smallest images from inside the human body. Endoscopes can be divided into two categories: rigid endoscopes, in which relay lenses are stacked together generally creating a high-quality image, and flexible ones-devices of lower cost where a camera is inserted near the tip of the endoscope while the […]
Fisheye Lens Design
Anyone who has peaked through a hotel room peephole has used a fish eye lens. Usually, the fish eye lens has a very short focal length (less than 15mm for a 35mm-size image sensor), but a large field of view (FOV). The latter can be as large as 180-degrees, giving the user a complete view […]
What are a ‘typical’ steps in lens design ?
Overview OFH works on many different types of projects, each with its unique goals and deliverables. For illustration, here is a breakdown of a lens design project from 2012. Our client produced a very low cost diagnostic microscope to view saliva with 30x magnification. They came to OFH to help them design a new product […]
Keratometer Optical Design
In this article, we will continue our description of different optical instruments used by optometrists. Last time we talked about Ophthalmoscopes, today we will talk about another very common optical instrument called the Keratometer. The keratometer was developed in 1851, it is used to measure the curvature of the anterior cornea. That is the outer […]