The Raw Advantage
What is the Raw advantage? It’s all in the word quality. Quality, quality, quality. It’s worth repeating. If you’re interested in the highest quality from your digital photographs, you should consider shooting Raw.
Now this doesn’t mean to say it’s always a compelling argument. For all sorts of reasons the highest quality may not be top of your picture wish list.
There are plenty of problems and provisos with shooting raw: The files are bigger and can take up more space on your memory cards, storage and backup systems; You cannot use a Raw file directly from the camera; it demands post-processing; this means a great deal of time and a good deal of skill. There’s not much point in shooting Raw if you don’t have the time or the skills.
If you’re certain that you want to send your pictures off very quickly, if you’re sure that your pictures are ephemeral, or if your output standards are going to be undemanding as they might be for small images on the web, then maybe Raw is not for you.
But I’m going to talk for the moment to photographers who want high quality. Why is Raw shooting the way to high quality? It’s quite simple. It’s because the Raw file contains a great deal of information and with that information you can construct the highest quality images.
Lets go back a bit to the great days of film photography and see if we can learn something there.
First of all most photographers know about the problem of correct exposure. The idea of correct exposure is to try to get onto your film or sensor all the information from the subject matter that you want to record in your picture.
The difficulty is that the lakes, the woodlands, the flora, the fauna, the faces, the places, the aeroplanes the racing cars the brides and grooms and all those other things that we photograph normally have dark areas and light areas, shadows and highlights such that more or less whatever we do we cannot record the whole range from the darkest to the lightest parts with one single exposure.
There are a number of solutions. How do we get the optimum exposure? A well tried solution is bracketing – that is taking a series of shots with slightly different exposures maybe the ‘correct’ exposure and one stop over and one stop under. I once remember recommending to a friend, “Bracket, bracket, bracket”.
The result of this is that at least one of these exposures should be the best possible. An obvious problem is that unless you are in a very carefully controlled environment you often can’t bracket. The subject must be more or less the same at each exposure. You can’t do it with speedboats or racing cars or in portrait photography trying to capture the fleeting moment. Here you only get one go.
In film terms there are other solutions such as choosing film and developer combinations to account for the particular contrast range. As long ago as the 1940s Anselm Adams and Fred Archer developed their famous Zone system which was especially useful when films or plates were individually processed.
These techniques are not directly relevant to digital capture.
Coming into the digital age we can of course continue with bracketing and this takes us onto HDR or High Dynamic Range. The principle is simple: Different exposures of the same subject are blended together to preserve all the highlight and shadow detail – a process sometimes discussed as tone mapping. Some high end photo editing programmes and some stand alone software programmes can help with this.
Exciting results are possible but there’s the same problem. You can’t really do this with different exposures unless the camera and the subject don’t move at all between shots. It’s worth noting that clouds scurry, water ripples and leaves wave in the breeze so it’s quite difficult to find subjects in nature where there really is no movement.
So the question is still – how can we try to get the contrast range we need with only one exposure?
So I’m going to invite you to leave my study and venture out into the local park with me and join in a practical photo shoot.
Another reason for this is to consider again the advice I gave to my nephew, Fergus Drennan. I suggested that the best quality lens for the least money would be a 50mm prime standard lens. In my case this is the Canon 50mm 1.8. So I thought to emulate what might be a useful task for him – to go and look for a suitable subject in the park with only this 50mm lens and no extra accessories.
The accessories point is quite important because as well as a solid tripod an experienced photographer might have an assistant and access to all sorts of reflectors and extra lights which could help reduce the contrast.
A word or two about the park: From my fourth floor apartment in Central Sofia I can look through the trees to the famous Boris Gardens. This great park was designed originally in 1882 by the Swiss landscape architect Daniel Neff with later additions by Joseph Frei and Georgi Duhtev. Local people tell me that some elements are modelled on St. James park in London.
From my point of view there’s a public part with cafes and playgrounds and popcorn sellers and a woodland area which I prefer where there are plenty of nature photo subjects such as trees, flowers and a variety of birds and animals. This is where I’m taking you on a day with hazy sunlight in the middle of the afternoon to find a large fungi growing on a fallen tree.
Now some of you might be bored by this idea. Perhaps you’re not nature photographers. I’m not sure that after all these years I care to put myself into categories but perhaps I can say that my very first published photo feature was in the Amateur Photographer Wildlife Special edition in, I think, 1970. I wrote of some techniques of insect photography. Now many years later I still love to go out and about in the mountains and fields looking at what is left of our seemingly vanishing countryside and photographing the birds, bees, trees, lakes and so on.
So back to the fungi where I believe that the natural light will provide good modelling and because the fallen trunk and surrounding branches should provide a sturdy support. I intend to take sharp pictures and I like to go even better than the maxim to use at least the same shutter speed as the focal length of the lens. In this case 1/50th of a second should prevent camera shake and I intend to use all the natural support I can get.
Now this is where I believe there’s clear proof for the Raw Advantage. I’m going to shoot off a few exposures and carefully check my histogram. My intention to is get as wide a tonal range as possible without blowing out the highlights and with as much shadow detail as possible so that I have the greatest possible information for use later on.
Although this could involve bracketing it is my intention to use only one exposure to make my final picture.
Here’s the technique.
First of all open the Raw file in your chosen programme. I’m going to use Raw Shooters essential. My intention is to output several 16 bit Tiff images from the same Raw file which have different exposure settings in Raw Shooter from the darkest to the lightest. Exactly how many is a matter of perception but the idea is to make sure that all the important parts of the subject have good detail.
Here are the darkest and lightest Tiffs I produced
It’s clear that with a Raw image it is possible to lighten the shadow areas without losing detail.
The next step is to use a photo editor which has layers as many do. Each different density Tiff is copied onto a separate layer.
For this picture I’m going to use a destructive technique using the eraser tool with a soft brush to simply wipe out all the data that I don’t want in my final image. This means erasing all the information on each layer which is too dark or too light – cherry picking the best from each layer so to speak.
When I’m satisfied I can flatten the image producing the final picture.
This is it.
I think I’ve managed to produce a picture with a much better tonal range than I’d get with a straight from camera JPEG.
Of course it’s a lot of work and some photographers would use a non-destructive approach. That’s the beauty of digital imaging, you can let a thousand flowers bloom.
Anyway I hope this illustrates the Raw Advantage and incidentally how quality can be enhanced by using high quality lenses and 16 bit images.