Please answer with detailed explainations. PHYSICS Image without flash Image wit
ID: 1730669 • Letter: P
Question
Please answer with detailed explainations.
PHYSICS Image without flash Image with flash Questions: Low light testin 1. Comment on the camera's ability to reproduce the scene in each case 2. Compare the images with your perception of the scene. Comment on any imperfections or limitations that you see 3. DISCUss any design limitations of the mobile phone camera from an optical perspective 4. The concept of gain is important in a digital imaging system. Briefly discuss the concept of gain and how it can affect image quality in a positive or a negative wayExplanation / Answer
1. A camera works by capturing reflected light from the object. The quality of image is dependent not only on the camera but also on how much light the object is reflecting in the direction of the camera.
In the first image, the object is set in a (slightly) dark environment. This means that the object has less light to reflect in the direction of camera. So, naturally, the camera is unable to reproduce the image of the object clearly.
In the second image, the object is illuminated with artificial lighting (flash). Due to the availability of more light, the object is able to reflect more. Hence, more features are visible.
2. The first image appears duller and the contrast between different components (like the title of the book, edges, the icons) is less compared to the second image with the flash.
Shadow behind the object can be seen in the first image. This is because the natural lighting is at an angle. This is not seen in the second image due to the flash light directly in front of the object.
The distance from which the photograph is taken is different for the two images. More ideal case to compare would be to take photographs of same object from same distance with and without flash. In other words, to keep all the other parameters constant except flash.
3. One of the major limitations is size of photo sensors. Larger the size of sensor, greater is the ability to collect light. But increasing the size of the sensors would increase the size and weight of the mobile phone.
Apart from this, to get better contrast and sharpness, other features have to be included. Which increases the cost as well as size of the mobile phone.
4. Gain is amplification of image. When the light signal is converted to electrical signal, it can be amplified using artificial means. The amount by which the signal is amplified is called gain. It is useful in darker settings and to brighten images.
If the light available in natural setting is less, gain can brighten the image by amplifying the signal. One of the drawbacks is that since it amplifies the signal, the random noise generated by the sensors is also amplified. This leads to more noise in image.