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Image Sensor in Camera

Image Sensor

Have you heard about image sensor in camera? You know how it works? the image sensor is located at the back of reflex mirror. The reflex mirror is like a door that open and close quickly, this reflex mirror is something a front cover of the image sensor to protect from bright light to over expose, but it doesn’t matter, it matters only after you see the results of your pictures. It could be completely dark or entirely white image.

The right side picture that you see like an LCD, actually it is called CCD or charge couple device has a filter of sensor that react to the light.

Now, this image sensor keeps hide in the dark inside the camera and this is the maker of picture every time you click the camera.

Below is the drawing and cross section of the camera see how the light enters the lens same what you see from outside through viewfinder, see now the sensor where located?

When you push the shutter button the reflex mirror flip quick and close quick faster than a second.

This is the sensor of camera look like, like a standing wall. This sensor is sensitive in any quantity of light, either small amount of light or much bright light.

The ability of this sensor is to react any kind of light then transmit to the memory card or SD card on your camera.

A screen shot of Image sensor format

The Shutter and Reflex Mirror

Now, in camera has many controls to prevent the amount of light. And because of this sensor there is mechanism to work as a team. There are two involve in this mechanism, the shutter and reflex mirror.

Shutter button Reflex Mirror


As you push down the shutter button the reflex mirror flip up.

This two are the primary cause that image sensor become free of receiving the light, as you start to push the shutter button the reflex mirror will flip up or open to enter the light.

What light I’m talking about? the light from outside that passing through, to your beautiful lens.


Not only the light is involved on this, but the all image outside as you aim the camera to the subject will copy all of them by the image sensor then transmit to memory card as your picture’s made on this, and auto saving.

Then you can instantly check the picture in LCD how it looks for you.

Imagine with the shutter speed in DSLR cameras can make continues shooting, as long as the reflex mirror open and close rapidly, the image sensor instant copying also because of receiving this light, copying the whole thing from outside to its frame size.

You get it now? how and why the image sensor work on camera? OK good. Here’s I created a quick video to show you how the reflex mirror flip up to enter the light going to image sensor.

What did you see in the above video? what see is only the reflex mirror that flip up. At the back of the reflex mirror is the Image sensor, but you didn’t see because its so quick faster than blink of an eye.

It sets to 1/60s shutter speed, enough to entering the light from outside, depend on your set up speed, how you will use. For example, at ease object or moving objects, these are all copy by image sensor.

The Reward, Once you understand…

Because if you understand this, when you go to aperture, in the ISO and the shutter speed you will see how to balance the exposure of the picture that you want, to a nice looking image. It is easy now for you to understand the sensitivity of image sensor. This image sensor is only waiting what lights to come in and copy it.

Now, think about your shutter speed and aperture, it matters on the image sensor? Yes, absolutely!

My point is that if you understand of its function, you do not need to look the book or give time again to research how to do better picture. After you examine the function the next step is your perspective, the inside of you will know how to make beautiful pictures.

Not only to study the triangle exposure. We want also to learn more about the image sensor, we want to know it’s sensitivity.

Not only if there is the sensitivity of aperture and shutter speed but also this square sensor the maker of picture. Although the three important control are need to master. The aperture, ISO and shutter speed. You can check here what is aperture and what is shutter speed how they work.

One thing I know that when adjusting the ISO speed , the image sensor read this adjustment what you set, how lighter or darker.

The Past SLR sensor image, there is?

SLR cameras use film or they called it negative film. After consume from shooting one roll of film they develop the film. To develop a film they use liquid chemicals to appear the images in the film, then clean with water and dry.

Dry the film then process to printing into postcard. Look how process here before to the photo paper, where is the image sensor here? Have you notice only film they used and no memory card 🙂

SLR and Film Negative Film

If you see at the back of the camera there is cover and open to reload the film, to reload film by fulling the film tip out then attach to the sprocket or shaft.

It should the film edge inserted to sprocket properly so that if manually pulling after one shot that you start, is exactly one FRAME.

But where is the image sensor in slr camera?

The negative film

If you full out the film it will expose all and turn into black and can’t be usable, inside is protect from dark. If you open the film should in dark room, see the similarity of the image sensor.

Film is like image sensor in SLR camera, the difference only is not digital most are manually.

I was a kid when I first learning SLR, I don’t know at that time what is image sensor, it seems the image sensor and sd card invented came from negative film idea to improve the easy use of camera in many process.

See the difference of SLR and DSLR?

A quick look to DSLR cameras today!

So, If you have any question about image sensor please leave them below and I will be more than happy to help you out.

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8 thoughts on “Image Sensor in Camera

  1. Now sums up the reason I always end up taking more better pictiures on my phone than I do with a camera. Before I do use to think that maybe it is just who I am but seeing how you have explained this here,it makes so much sense to see. There needs to be timing and to get the perfect right movement too. This is really good for me to know of.

    1. Hi, DarmiMaddie. I’m glad that this article make sense to you. Timing is one of important tool in taking pictures, it contribute not only the condition to balance the light that you choose but also the actual action or movement of the subject that is present.


  2. Hello,thank you for sharing this informative and educative article. This article is centered on a image sensor in camera. This article is very explanatory and I now understand everything about image sensors in camera. Now I know why I always end up taking bad pictures with my camera. Thank you for the enlightenment

  3. It’s good to always read through things that you totally have no idea about, it widens your understanding and it allows you to know things. This article about image sensor in camera is very interesting and ive learned a lot of things From it. Thanks for sharing this amazing article, it’s filled with good stuff.

    1. There are many things we want to learn more, how and why and what purpose. I believe that anyone can learn to it and can be in anything or any device, whatever you are interested in. Thanks a lot Jbryce, for reading my article.


  4. I have learnt so much just reading this post. It’s like a “ahh” moment. I had heard explanations before about sensitivity of aperture and shutter speed. But they hadn’t dawn to me yet. I have re-read twice your post and now it appears so simple to me. Thank you very much!

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