Analog to digital signal converter in digital cameras

[rudransh verma]

I am reading How computers work and I don’t grasp it. So how is light ultimately get transformed into a beautiful picture on screen in a digital camera? I have got D5200 Nikon. It’s a nice begineers camera.

 

[anorlunda]

This video may help you get started. To understand the whole thing at the deepest level would be a lifelong project.

 

[DaveE]

I guess from your title you are asking about the ADC part of the signal processing. There are several different types of ADCs and I'm not sure all cameras use the same type. I would guess SAR and Σ-Δ are the most common for still pictures. Here's one of about a million articles about ADCs on the web.

https://www.analog.com/en/analog-dialogue/articles/the-right-adc-architecture.html

 

[rudransh verma]

I guess from your title you are asking about the ADC part of the signal processing. There are several different types of ADCs and I'm not sure all cameras use the same type. I would guess SAR and Σ-Δ are the most common for still pictures. Here's one of about a million articles about ADCs on the web.

https://www.analog.com/en/analog-dialogue/articles/the-right-adc-architecture.html

Does this come under electrical engineering ?
I read it and it Looks difficult to understand completely. I found about it in “How computer works” book and was curious to understand it. But I think I have to go back a bit and first understand the basics.
https://www.tanguayphotomag.biz/photo-editing/adc-and-your-digital-cameras-bit-depth.html
This is a simple explanation but I don’t get the pixel part
“These digital pixels consist of data bits that establish exactly what color that pixel will be. The more bits, the more possibilities for more precisely defining the color's hue, saturation, and brightness. Most inexpensive digital cameras process 8-bit pixels. Better digital cameras may have 10 bits or 12 bits per pixel. That's good, because more information usually translates into better color, more subtle transitions or gradations, and increased clarity of detail in the highlights and shadows. Professional digital cameras and studio digital cameras may even associate 14 or 16 bits of data with each pixel.”

 

[DaveE]

Does this come under electrical engineering ?

Yes. Analog EE, really.

I read it and it Looks difficult to understand completely. I found about it in “How computer works” book and was curious to understand it. But I think I have to go back a bit and first understand the basics.

There is a lot of information out there about this. The link I gave may be a bit too advanced initially. But I'm sure there are others that start more slowly. Search the web for ADCs and you'll find the appropriate level for your knowledge and interest. However, one problem is that there are some quite different solutions to this. You may not care enough to study all of the different versions, since they all do the same job at the basic level.

I would start with SAR (successive approximation) ADCs.
The basic idea here is like an intelligent way to solve this problem:
I'm thinking of a number between 0 and 127, figure out what it is with a minimum number of questions.
1) Is it less than 64? Yes.
2) Is it less than 32? No.
3) Is it less than 48? No.
4) Is it less than 56? Yes.
5) Is it less than 52? Yes.
6) Is it less than 50? No.
7) Is it less than 51? No.
8) Then it must be 51.

Each question splits the remaining unknown range in half. The sequence of yes/no answers gives the binary representation of the number. 51₁₀ = 0110011₂.

 

[sophiecentaur]

So how is light ultimately get transformed into a beautiful picture on screen in a digital camera?

It's 'painting by numbers'. Each element on the sensor (pixel) is a 'sample' of the image of the scene that's on the sensor array. (Those are 'samples') The Analogue values of the light signal on the sensors are changed (quantised) into digital numbers and all those millions of numbers are fed to (mapped into) the camera memory memory.

Because it's colour, there are three kinds of sensor, in a matrix and basically the R, G or B value of each pixel goes to a pixel on your display screen. Most cameras will store the image data using fewer memory elements than there are sensor pixels to save storage. There is a lot of clever processing in the camera and display which improves the picture by, for instance, adjusting the colour balance and sharpening up the image so the unpromising picture you take with your camera turns up at the other end with (sometimes aurtomatic) improvements.