4.11.3.1 - Lens stereoscopes
Enroll to start learning
You’ve not yet enrolled in this course. Please enroll for free to listen to audio lessons, classroom podcasts and take practice test.
Interactive Audio Lesson
Listen to a student-teacher conversation explaining the topic in a relatable way.
Introduction to Lens Stereoscopes
🔒 Unlock Audio Lesson
Sign up and enroll to listen to this audio lesson
Today, we're diving into lens stereoscopes. Who can tell me what a lens stereoscope is?
Isn't it a device used to view 3D images?
Exactly! Lens stereoscopes allow us to view stereo-pairs and create a 3D model. Can anyone explain how this is done?
I think it uses two images taken from slightly different angles...
Correct! This mimics human binocular vision. Let's remember this as 'Two Eyes, One View'—it'll help you recall that concept.
So, how do we adjust it for different users?
Great question! The distance between the lenses can be adjusted according to the user's eye base, which is normally about 65 mm.
What about its size? Can it fit in our pockets?
Yes, that’s why it's called a pocket stereoscope! Its lightweight design makes it very portable. Let's summarize: lens stereoscopes create a 3D effect using two images, adjustable for user comfort, and portable for field use.
Construction of Lens Stereoscopes
🔒 Unlock Audio Lesson
Sign up and enroll to listen to this audio lesson
What do you think makes up a basic lens stereoscope?
Lenses and a frame, right?
Yes! It's made of two plano-convex lenses mounted on a metallic frame. But what function do these lenses serve?
They magnify the images?
Correct! This magnification is crucial for depth perception. Remember, 'See Clearly, Learn Deeply!' This will help you recall their purpose.
What’s the effect of the distance between the lenses?
It adjusts to the user’s eye base, allowing for a more comfortable viewing experience. So, the more personalized it is, the better the experience!
Can these stereoscopes fit larger photographs well?
Good observation! They have some limitations in viewing larger photographs due to their field of view. Let's recap: lens stereoscopes consist of adjustable plano-convex lenses on a frame, designed for effective 3D viewing.
Advantages and Disadvantages of Lens Stereoscopes
🔒 Unlock Audio Lesson
Sign up and enroll to listen to this audio lesson
Let's discuss the advantages of lens stereoscopes first. What's a major benefit?
They’re portable!
Absolutely! Their lightweight design allows them to be very portable. Can anyone remember another advantage?
They are cost-effective?
Exactly! They are affordable compared to other options. Now, what are some disadvantages?
Limited magnification, right?
Yes, they typically provide between 2x and 4x magnification, which can be limiting. Remember, 'Magnify to Clarify'—that’s an easy way to recall their magnification limits.
And limited field of view?
Correct! This limits their usability with larger photographs. So, let's summarize: lens stereoscopes are portable and cost-effective but have limitations in magnification and field of view.
Introduction & Overview
Read summaries of the section's main ideas at different levels of detail.
Quick Overview
Standard
Lens stereoscopes enable viewers to see 3D models from stereo-pairs, providing depth perception through the fusion of images taken from slightly different angles. This section details the design, functionality, and limitations of lens stereoscopes in capturing 3D views.
Detailed
Lens Stereoscopes
Lens stereoscopes, commonly known as pocket stereoscopes, are portable optical devices designed for viewing stereo-pairs of photographs. These devices enable the observer to perceive three-dimensional scenery by presenting slightly different images to each eye, mimicking the natural function of human binocular vision. This section discusses the construction, operation, and comparative advantages and disadvantages of lens stereoscopes in the context of photogrammetry...
Construction and Functionality
A lens stereoscope typically consists of two plano-convex lenses mounted on a lightweight frame with adjustable distance between the lenses to accommodate different eye-sizes. The lenses magnify the images, allowing for clearer viewing and depth perception. The standard eye base distance for humans is approximately 65 mm, and the device is designed to reflect this.
Advantages and Disadvantages
The primary advantages are portability and affordability, making them suitable for fieldwork with small-format aerial photographs. However, limitations include restricted magnification (generally 2x to 4x) and a limited field of view, which can present challenges when studying larger-sized photographs. Overall, lens stereoscopes serve a critical role in enabling photo-interpreters to engage with aerial imagery effectively.
Audio Book
Dive deep into the subject with an immersive audiobook experience.
Overview of Lens Stereoscopes
Chapter 1 of 4
🔒 Unlock Audio Chapter
Sign up and enroll to access the full audio experience
Chapter Content
Lens stereoscope is also called as pocket stereoscope, as it can be kept in pocket owing to its small size. Being light-weight, it is easy to transport in the field, if required. It consists of two plano-convex lenses with magnifying capability, which are mounted on a metallic frame.
Detailed Explanation
A lens stereoscope, often referred to as a pocket stereoscope, is a compact optical device designed for viewing stereo images. Its lightweight and portable nature make it suitable for field use. The device comprises two plano-convex lenses that serve to magnify images. These lenses are mounted on a metal frame that holds them in place, ensuring stability when viewing the images.
Examples & Analogies
Imagine using a pair of binoculars while bird watching. Just like binoculars allow you to see distant birds clearly, a lens stereoscope magnifies stereo pairs of photographs to create a three-dimensional view, helping you see details that would be difficult to discern with the naked eye.
Adjustable Features of Lens Stereoscopes
Chapter 2 of 4
🔒 Unlock Audio Chapter
Sign up and enroll to access the full audio experience
Chapter Content
The distance between these two lenses is adjustable as per the comfort of users’ eyes. The eye base average distance is approximately 65 mm for a human-being. The height of pocket stereoscope is normally 10 cm, but its legs can be folded when not in use.
Detailed Explanation
One of the practical features of lens stereoscopes is the adjustable distance between the two lenses. This adjustability accommodates different users’ eye distances, which averages around 65 mm. The typical height of a pocket stereoscope is about 10 cm, and it is designed with foldable legs for easy storage and portability.
Examples & Analogies
Think of wearing glasses. Just like glasses can be adjusted to fit comfortably on different face shapes, a lens stereoscope allows users to customize the distance between lenses for optimal viewing, ensuring a clear, comfortable three-dimensional picture.
Functionality of Lens Stereoscopes
Chapter 3 of 4
🔒 Unlock Audio Chapter
Sign up and enroll to access the full audio experience
Chapter Content
Distance between legs of the stereoscope and the focal length of lenses are normally so designed that the stereo-model can be created.
Detailed Explanation
The design of a lens stereoscope includes specific arrangements for the distance between its legs and the focal length of its lenses. These elements work together to create a three-dimensional model from stereo images. When correctly aligned, they facilitate the visual perception of depth, enabling the viewer to judge distances more accurately.
Examples & Analogies
Think about how car headlights are positioned. Just as the angle and distance between car headlights help illuminate the road ahead effectively, the arrangement of the legs and focal lengths in a lens stereoscope ensures that images are viewed from the right perspective, allowing the viewer to understand the spatial relationship between objects.
Advantages and Disadvantages of Lens Stereoscopes
Chapter 4 of 4
🔒 Unlock Audio Chapter
Sign up and enroll to access the full audio experience
Chapter Content
Lens stereoscopes are handy, economical and light-weight, and thus convenient for studying the small format aerial photographs. They have disadvantages, such as limited magnification (2x–4x), and limited field of view to view the larger size photos in 3D at one single glance.
Detailed Explanation
Lens stereoscopes present several advantages such as portability, affordability, and lightweight construction, making them practical tools for analyzing small-format aerial photographs. However, they also have some limitations, including a magnification range of only 2x to 4x, which may not be sufficient for all applications, and a restricted field of view when attempting to view larger photographs in three-dimensional form.
Examples & Analogies
Consider a magnifying glass. While it can help you read tiny print on a map, it can sometimes make it hard to get a full view of the entire map at once. Similarly, lens stereoscopes are excellent for detailed examination but might require another type of tool when needing to view a larger area comprehensively.
Key Concepts
-
Lens Stereoscope: A device that provides 3D vision through stereo-pairs of photographs.
-
Plano-Convex Lens: Essential for magnifying images in stereoscopes.
-
Binocular Vision: The ability to see depth using both eyes, crucial in stereoscopy.
Examples & Applications
An aerial photograph of a landscape viewed through a lens stereoscope typically presents mountains and valleys with enhanced depth perception.
Using lens stereoscopes in fieldwork allows surveyors to accurately interpret land features by providing a three-dimensional view.
Memory Aids
Interactive tools to help you remember key concepts
Rhymes
See two views, get it clear, 3D vision's drawing near!
Stories
Imagine two friends looking at a view from different angles, and when they combine what they see, the landscape pops out in 3D!
Memory Tools
To Remember Lens Stereos: 'Light & Easy' - Light for portability, Easy for operation.
Acronyms
L.E.N.S
Lightweight
Efficient
Navigates Spectrums.
Flash Cards
Glossary
- Lens Stereoscope
An optical device used to view pairs of photographs for creating a three-dimensional effect.
- PlanoConvex Lens
A lens with one flat side and one curved side, used in stereoscopes for magnification.
- Binocular Vision
The ability to perceive depth and dimension by using both eyes to view slightly different images.
- Eye Base
The average distance between a person’s eyes, typically around 65 mm for adults.
Reference links
Supplementary resources to enhance your learning experience.