Are You Shooting In The Best Image Quality
Today’s cameras are a marvel of technology, giving us image quality that just a few short years ago, most of us could only dream about. However, despite the incredible quality we can get from our camera’s many of us are not maximizing the camera sensor’s true potential.
In this article we are going to have a look at two very important techniques for getting the very best image quality in your shots, namely shooting RAW and shooting to the right.
Let’s start with shooting RAW as this will lead us nicely to the second technique. What is a RAW file? Well the best description is that it is a digital negative. In fact the term RAW also perfectly describes the files as what it is, is the unaltered raw digital information recorded directed to your memory card.
Why Shoot RAW?
So what are the advantages of this? When you shoot jpeg or even tiff files, the camera will make a number of adjustments to your image, thee include, white balance, compression, sharpening and in some cases contrast adjustment. The camera is trying to give you the best image, based on the scene it understands you are taking. The problem is, that in many cases this is not entirely what you, the photographer, wants to achieve.
A RAW file removes all those camera adjustments and gives you the ability to control all of them in post production via a RAW converter. Gone are the days when RAW files were deemed difficult to use and with excessive file sizes. Most image management software has built in RAW editing ability. That can make big image quality differences over a standard jpeg version of the image.
The big advantages of RAW files include, an often significantly wider dynamic range, in other words you can squeeze more tones in-between the pure white and pure black, you can set the color temperature in post production. This gives you the advantage of recreating the color exactly in the scene or changing it to suit and to apply your own levels and sharpening to the image.
RAW files are an important way to increase your image quality. The second technique, shooting to the right, enhances this further.
Shooting To The Right
The term shooting to the right means that you are trying to get the majority of your exposure on the right side of the histogram. So before we go any further, let's have a look at what a histogram is and how to interpret it. Histograms are the graphs that you can look at on your camera’s LCD screen, basically it shows you the quality of your exposure.
You may need to have a look in your settings to find how to display the histogram and if your camera gives you the option, use a Red/Green/Blue histogram as this will better indicate your exposure information. So how do we interpret a histogram?
Reading The Histogram
The easiest analogy is to think of the histogram as a bucket of light, we are aiming to keep the light inside the sides of the bucket. Any part of the graph that is spilling off the left side of the bucket is under-exposed and any spilling to the right is over-exposed. In general, a camera’s metering system will try to keep all the light right in the middle of the bucket.
This is called the metered exposure. However due to the way sensors react to light, there is a slight anomaly, the more of the light you can move to the right of the histogram, the better your image quality will be. The reasons for this are quite technical and I will not go into too much detail but put simply, modern camera sensors are more efficient at capturing light at the brighter end of the exposure than the darker.
So when we are shooting, what we are aiming to do is to get the bulk of our histogram to the right side of the bucket, without any of it spilling out of the sides and as RAW gives us a wider latitude, we should be using only RAW files to maximize the effect. If the bulk of our exposure is in the middle or to the left, this means we need to open the aperture or lower the shutter speed. If we find some of the exposure has spilled over to the right we will need to close down our aperture or raise our shutter speed. If you look at the image either on the screen of your camera or your computer, it will seem that it is over exposed but this is fine because we will correct the exposure in post production.
Correcting The RAW For Best Image Quality
So, using RAW software we can correct the image, mainly by bringing the levels down for the mid-tones giving us a correctly exposed image as it appears on a color corrected monitor. The big advantage of this technique is that it allows us to reveal a lot more detail in shadow areas without introducing excess noise and maximizes the dynamic range of the sensor.
Using a combination of both these techniques, you can push your image quality to the very edge of the sensor’s envelope, giving you better shadow definition, dynamic range as well as details in the highlights.
Feel free t ask questions about maximising image quality in the comments below.