Calculate the distance at which an object should be placed in front of a concave lens of focal length 30 cm to obtain an image of half of its size.
![Emsley's Model Eye used to calculate the projected retinal image size.... | Download Scientific Diagram Emsley's Model Eye used to calculate the projected retinal image size.... | Download Scientific Diagram](https://www.researchgate.net/publication/337036903/figure/fig1/AS:946485814382592@1602671211093/Emsleys-Model-Eye-used-to-calculate-the-projected-retinal-image-size-L-D-L-D.png)
Emsley's Model Eye used to calculate the projected retinal image size.... | Download Scientific Diagram
![python - Calculate the physical object size in m knowing its distance ,focal length and pixel size in image - Stack Overflow python - Calculate the physical object size in m knowing its distance ,focal length and pixel size in image - Stack Overflow](https://i.stack.imgur.com/35oFA.png)
python - Calculate the physical object size in m knowing its distance ,focal length and pixel size in image - Stack Overflow
![calculations - What is the relationship between size of object with distance? - Photography Stack Exchange calculations - What is the relationship between size of object with distance? - Photography Stack Exchange](https://i.stack.imgur.com/whv1F.png)
calculations - What is the relationship between size of object with distance? - Photography Stack Exchange
![Magnification and resolution how to calculate size and magnification from an image of an object how to calculate size and magnification from an image. - ppt download Magnification and resolution how to calculate size and magnification from an image of an object how to calculate size and magnification from an image. - ppt download](https://images.slideplayer.com/42/11404098/slides/slide_6.jpg)
Magnification and resolution how to calculate size and magnification from an image of an object how to calculate size and magnification from an image. - ppt download
![A real image, 1/5^th the size of the object, is formed at a distance of 18 cm from a mirror. What is the nature of the mirror? Calculate its focal length. A real image, 1/5^th the size of the object, is formed at a distance of 18 cm from a mirror. What is the nature of the mirror? Calculate its focal length.](https://toppr-doubts-media.s3.amazonaws.com/images/2624083/1e9c86ad-354f-4e34-af74-72042c00e4a5.jpg)
A real image, 1/5^th the size of the object, is formed at a distance of 18 cm from a mirror. What is the nature of the mirror? Calculate its focal length.
![Can we calculate object distances by changing camera position and "measuring" pixel sizes of objects - Photography Stack Exchange Can we calculate object distances by changing camera position and "measuring" pixel sizes of objects - Photography Stack Exchange](https://i.stack.imgur.com/kgd0k.png)
Can we calculate object distances by changing camera position and "measuring" pixel sizes of objects - Photography Stack Exchange
![The size of image of an object, which is at infinity, as formed by a convex lens of focal length - YouTube The size of image of an object, which is at infinity, as formed by a convex lens of focal length - YouTube](https://i.ytimg.com/vi/FkXBLj31eWY/maxresdefault.jpg)