Unprocessed photos straight from the camera

Microstock photo banks offer millions of photos, a large number of which end up on blogs. Here on read.cash I benefit from the content submitted on Unsplash and Pexels. I have the right photography gear, so I could be taking photos myself but for the purposes of blogging, it would be way too time consuming to both write and take the suitable photos in mind for every single article. Well, maybe if I were blogging for a living but I doubt I'll ever reach that level (which is not demotivating by any means!).

So, I noticed that my article about apps for photo processing was viewed by many people, so I was wondering whether at some stage I should make some photo editing tutorials. Essentially, editing photos taken with a phone or with a digital camera follows the same idea. This is why in the discussion below by "camera" I mean any device that can produce an digital image.

Steps to obtaining an image

• Light hits the camera sensor

• The light-sensitive transistors in the sensor turn it into an electric signal

• The signal is processed in order to recover the colour information (also called demosaicing)

• Preliminary processing is done: brightness, gamma curve, white balance

• The data is either saved in RAW format or compressed and saved as JPEG.

This photo is straight from the camera, photo processing is cheating!

Sorry... anyone who says that is simply unaware of how a digital camera works. As you saw yourself above, the camera already does plenty of processing in order to obtain an image. It is inevitable for various reasons, the main of which is that our eyes have non-linear perception of light and dark tones. We better distinguish between dark tones than light ones. On the contrary, the camera sensor perceives them equally well. If we shine twice the amount of light on the sensor, it will always perceive it as twice as bright. This is a linear response. But for us, it matters whether these are the dark tones or the light tones. This is the purpose of the gamma correction.

Also, if we were to leave a photo completely unprocessed, it will be black and white. The light sensitive transistors don't know what colour is. The can only tell the amount of light coming. There a small caveat that they're sensitive to certain wavelengths of light. If I were to shine far IR, it will barely capture anything. Colour digital photos are possible thanks to the array of very tiny filters on top of each pixel of the sensor. They are arranged in a certain order, in groups of four. In each group there are two green, one red and one blue. Again, the additional number of green pixels is due to the way our vision works. Our eyes are more sensitive to green. This array is called the Bayer matrix.

Some parameters can be set later

Saving a photo in RAW format allows some settings to be adjusted afterwards in a program or an app without a notable loss in quality. The major benefit of RAW format is that it stores the data captured by sensor uncompressed. Compression reduced the amount of data encoded in the image and details are lost irreversibly. Not every program can read RAW files since it needs to know what is the structure of the data carried by the RAW file but also it should know how to perform the demosaicing (recovering the colour). Setting the white balance can be done at the post-processing stage easily and tends not to cause any artifacts. It simply is a way of defining what is neutral white in that picture. Remember that dress from a few years back...