Dear Abdelrahman Elfauomy,

Answering your important question:

“What is the arrangement of lenses on double image ocular at tool maker microscope?”

In a tool maker’s microscope with a double image ocular (also called a coincidence or split-image eyepiece), the arrangement of lenses and optical components is specifically designed to allow precise measurement by creating and comparing two images of an object.

The double image ocular (Coincidence Eyepiece) lens arrangement is comprised of:

1. Objective Lens: located at the bottom of the microscope. It forms a real, inverted image of the object on the stage.

2. Beam-Splitting System (usually inside the eyepiece): this is the core of the double-image mechanism. It typically involves a prism, wedge, or semi-reflective mirror that splits the light path from the image into two.

3. Measuring Prism / Wedge System: a movable prism or optical wedge is included in one of the two paths. By adjusting this prism, one image can be moved horizontally or vertically relative to the other.

4.Reticle (Crosshair or Scale): often integrated in the eyepiece to aid in precise alignment and measurement. It helps determine when the images have overlapped exactly.

5. Eyepiece (Ocular Lens): combines the split images and magnifies them for viewing. The final image seen by the user is a composite image made by aligning the two slightly displaced images.

Sincerely yours,

Daniel Fragoso

References:

1. Evident (2025) Eyepieces (Oculars). Avaiable at: https://evidentscientific.com/en/microscope-resource/knowledge-hub/anatomy/oculars?utm_source=chatgpt.com (Accessed at: 07/06/2025)

2. Microscope World (2025) Microscope Parts & Specifications. Available at: https://www.microscopeworld.com/t-parts.aspx?utm_source=chatgpt.com (Accessed at: 07/06/2025)