Tuesday, April 24, 2012

Photographing in RAW!

Rightyo, long time since I last updated. Soon, I hope to be able to bring all my art from school back home, and then ill hopefully have more traditional art stuff to show you guys. What i thought to show you today, though, is a bunch of photographs I took this morning for an art project. We actually found this nice abandoned house just downtown, which just looked like an awesome place to take some photographs, and it was. Dark, no lights, just windows. Pools of water on the floor, scraps and heaps of crap everywhere, just this very tangible sense of abandonment and dread hung over the place. First 2 photos are from there, and the third is just some random railroad I photographed earlier.

Shot with a Canon 450D camera, and edited in CameraRaw (A plugin for Photoshop.). The RAW format, which I just recently found out about, is fucking great, quite frankly. Instead of saving a value and color for every pixel, it records how much light that hit the sensors in the camera. JPEG will only save 255 shades of grey, and that leaves you with very little editing room, as 255 shades is also just how much your monitor will display, if im not mistaken. On the contrary, imagine a format that would record every wave/particle of light that hits the camera. Thats basically what the RAW format does.

Well, not really. Prepare for some tough reading now... A color camera basically works so, that one pixel is made up of 3 (or 4, but thats irrelevant) light sensors. One for red, one for green, and one for blue. They block out all the light which is the wrong frequency (colour.) and only let only one, say green, in. Then the energy absorbed by the plate behind the lens is measured. The pixels other 2 sensors take care of the other 2 colours. Of course, you guys know that any color can be fabricated using RBG, right? 255 Green, 255 Red, 255 Blue will make 255 White. 255 for each channel makes 255^3, which is about 16.7 million colours. That might sound like it gives you alot of editing headroom, but in comparison to the spectrum RAW offers you, 16.7 million isnt all that much. Ill demonstrate this in a future blog entry.

Notice that your screen will still only display 16.7 million colours even though the image has higher depth.

Now, we now exactly how much Green light hit the sensor. Same goes for red and blue. Then it saves this data in a temporary format, which is raw. Simply put, RAW is data for how much energy was transmitted into every sensor individually. Normally, the camera then by itself interprets the RAW, and then saves it in a jolly nice small JPEG, and scraps the RAW. Modern cameras give you the option to save in RAW instead, and do the interpretation by yourself, and then save it in JPEG. This makes all the difference. Cameras suck at interpreting photographic data, ironically enough.

EDIT: Another explanation of how camera sensors work can be found here, if you didnt get it http://www.cambridgeincolour.com/tutorials/camera-sensors.htm

AND SO, to conclude why JPEG sucks in comparison to RAW, for those who havent figured it out yet, JPEG will be saved in a depth of 255 shades grey, while RAW will be saved with a practically infinte amount of color depth, and all the original data. This means you can change things like exposure, white balance, value curves etc afterwards, without losing ANY quality AT ALL.

Also note that there are many different RAW formats. They all serve the same purpose, and work the same way. Support by software might wary, though. My camera saves in .CR2.

I feel my description is lacking with my shoddy explanation completely void of pictures, and so ill make a for-dummies comparison for my next update :D The advantage is best seen using pictures for examples, anyway.

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