The photo above was taken inside the Pavilion of Future at the Taipei International Flora Expo with Canon EOS 5D Mark II with Canon EF 100mm f/2.8L IS USM Macro. The RAW file was converted with Capture One Pro 5 to TIFF with further post-processing done with Adobe Photoshop CS5 before final output. I am quite satisfied with the final result and I think it looks pleasing enough. Why did I process the photo to look like this? Because that was how it appeared to me in real life when I saw the flower.
However, how did the shot look like before post-processing? Take a look below.
The photo was straight out of the camera with basically no post-processing done other than re-size for web output. Because it was rather crowded inside the Pavilion and the crowds were constantly moving, there was little time to setup the camera ideally for each shots, so I basically left the camera in aperture priority mode with no exposure compensation and auto white balance. It is easy to see the resultant image was not really ideal and does not look pleasing, looking rather dark and under-exposed with a ugly yellowish cast.
Without going into technical details as to why the camera came out with a photo looking like the one above, which do you think was telling the truth? The shot straight from the camera or the one post-processed by me to look like what I think it looked like when I saw it in real life?
Well, the shot straight from the camera was actually the more truthful shot. In the actual scene, the flower was at an indoor area of the Pavilion with artificial lighting only and the light intensity was not very bright either. The artificial lighting has a color temperature that is warmer (more yellowish) than natural light from the Sun. So the camera actually saw all that and recorded an image that was on the dark side with a yellowish tint.
So how come what I saw at the scene was different from the camera? That is because our brain is very smart and in fact a very good liar. The brain has an imaging processing engine that is smarter than any camera. It will automatically adjust the exposure and color balance to a pleasing level. Because our brain actually believes the flower is white in color rather than yellow, so it would adjust it to appear white, and out brain also does not like seeing a poorly illuminated darkish scene, so it would make the scene appeared much brighter than reality.
The camera does not have the power of the brain. It is really quite dumb, but rather honest. It just recorded quite faithfully what the scene really looked like.
The camera is dumb but honest. Out brain is smart but a liar.
So what is the moral of the story? Because the camera does not work like our brain, the image it records under artificial lighting is usually not pleasing because our brain does not like to see the truth, it likes see lies. What we need to do is to make a photo that lies in the same way as the brain.
How can we achieve this? There are 2 ways to do this. We can either make the camera lies like our brain by making adjustment to the camera settings before capturing the photo. You need to adjust exposure by by adding maybe 2/3 to 1 EV when taking indoor photos under artificial lighting (especially tungsten lighting) and either set a custom white balance with a gray card or set manual white balance with the appropriate color temperature.
The second way was to do post-processing as in what I have done above. You can adjust white balance and brightness to make the photo looks pleasing to the eye.