Digital Workflow – Part 1: Digital Photography in the field.
It is often said, “The benefit of digital photography is that the photographer has total control. The bane of digital photography is that the photographer has total control.” Truer words were never spoken. When I made the switch from film to digital, it quickly became apparent that digital photography was the same as film-based photography. I selected the shutter speed and aperture combination, adjusted the exposure and pressed the shutter button. Now let me contradict myself by saying that digital photography is very different than film photography. To be more precise, digital processing is very different then film processing.
With film, once the film is exposed I sent it off to the lab and they take care of the rest. As a digital photographer, I am the lab. It is my job to process the images, make adjustments, and perform retouches. The key to mastering digital photography is in developing a workflow that allows you to move efficiently from conception to the final image.
Digital workflow can be divided into three broad categories: photographing in the field, working with images on the computer, and managing image collections. Through this series of articles, we will examine the options available and how to streamline your efforts. Part I will focus on working with a digital camera in the field. Part II will concentrate on image editing and fine-tuning images on the computer. Part III will address organizing and managing your image collections. As I developed my skills as a digital photographer I realized that digital workflow is personal and a photographer’s ability to streamline that workflow will have a major impact on how much they enjoy digital photography. With the right workflow, post-processing can be efficient, allowing more time to take pictures. In these articles I will discuss my digital workflow and the issues and concerns that went into its development.
Digital Photography in the Field
When heading out into the field, my first step is to decide what equipment to take with me. In addition to the standard photographic equipment, I now include a selection of gear specific to digital photographers. First and foremost is the digital camera. Digital SLR (dSLR) cameras are largely comparable to film cameras with the exception that the camera itself dictates maximum image resolution rather then the film. For my own uses, Canon’s 1DmarkII and 1Ds dSLR cameras meet my needs. In most cases, I shoot with the 1DmarkII for its high frame rate (8 frames a second) and outstanding image quality, reserving the 1Ds as a backup camera.
While digital cameras can be tethered directly to a computer, this is not practical for nature photography. In fact, downloading images in the field does not work well with my style of photography. I prefer to carry enough CF memory cards to last the entire day. I usually carry between 12-16 GBs in CF memory cards, switching cards as they fill up. My cards range in size from 1-4 GB. Shooting in the RAW format I can fit either 360 images (1DmarkII) or 284 images (1Ds) on a single 4-GB card. Larger CF cards are available but I prefer not to put too many eggs in one basket. Spreading my images over multiple cards, I reduce the risk of loosing all the images from a shoot if a problem occurs. When not in use, CF cards are carried in a small card holder on my belt. When a card is full, I store it in the holder facing backwards indicating it contains images and needs to be downloaded.
I also carry a spare set of rechargeable batteries for both cameras. Digital cameras are more like computers than film cameras and require more battery power to function. Nine times out of ten, a fresh battery will last me through the day. However, if great subjects abound, I want to have a spare battery at the ready.
The next step is determining what camera settings to use. Digital cameras have an array of settings that effect not only the ability to capture an image, but also how the final image will appear. The settings anyone chooses depends largely on the ultimate use for the images. In my case, camera settings are selected to produce the highest image quality without making too many alterations to the basic image.
The foundation of my workflow system is the RAW file format. This is the “RAW” image from the sensor, without adjustments being applied by the camera. RAW files can be adjusted at a later date and fine-tuned to my heart’s content. The RAW format permits me to adjust exposure, white balance, bit depth, and other key image characteristics after the initial capture. This allows corrections to be made and creative options, that were not previously possible, to be pursued. On the downside, RAW files are large, limiting the number of images that can be fit on a single memory card. RAW files also require a greater commitment of time for post-processing and are not recognized by many computer programs.
Color space is an issue that has no film equivalent. We are starting to enter the realm of color management, a topic that fills books the size of your local phone book. The good news is that mastering color management theory is not necessary to use the camera. In its simplest form, color space is a method computers use to interpret and display color. Most digital cameras offer two color space options: Adobe RGB and sRGB. Adobe RGB has a wider color gamut than sRGB. This means that the Adobe RGB color space offers a wider range of colors, translating to more colors in the images.
Camera manufacturers recommend digital photographers use sRGB because they are trying to make life easier for the average digital photographer. The sRGB color space has a color range that is very similar to what is seen on a computer monitor. Since most digital photographers view their images on a monitor, it makes sense for them to use the sRGB color space. By recording images in the Adobe RGB color space, I am recording the greatest range of colors possible. I can always convert the image to sRGB later if I want. In the meantime, I know the extra color detail is there if I ever want it.
White balance is another setting digital photographers can adjust. Time of day and the light source have an impact on the temperature of light and how it is rendered in the final image. For example, at sunset, the light has a distinctly golden/yellow color cast. Wait 30 minutes following the sunset, however, and the visible light will have a strong blue color. The human eye is outstanding at compensating for different color casts. Cameras, on the other hand, are more easily fooled. White balance helps to compensate for changes in color temperature. With film, there were only two choices: daylight or tungsten. With digital, choices include sunlight, shade, cloudy, indoor, florescent, and custom white balance. I often get so focused on the subject that I forget to adjust the white balance. After all, this was not done with film. Fortunately, camera manufacturers have taken people like me into account and provided an auto white balance setting. My experience is that auto white balance is usually accurate and adjustments are easy to make during post-processing provided you are shooting in the RAW file format.
The remaining camera settings are designed to adjust the appearance of the final image such as saturation, contrast, sharpening, etc. I prefer to leave these camera settings at the minimum level. Having the camera make adjustments saves time. However, I feel that each image is unique and should be adjusted on a case by case basis rather then applying a generic setting to every image.
Working in the Field:
Using a digital camera in the field differs from film in several ways. First, you don’t have to change “film” as often so there are fewer excuses for not getting the shot (wait, fewer excuses….this might not be a good thing). Also, the availability of the histogram to fine-tune exposure and the ability to review your images while in the field are new options.
The ability to review the histogram while shooting is one of the greatest benefits of digital. A histogram is simply a bar graph showing how pixels are distributed between black (left side) and white (right side). Reading the histogram serves two important functions. I can check the basic distribution of pixels in the image to make certain they match the image as I pre-visualized it, and I can check exposure simply by glancing at the histogram. My experience has been that digital cameras are excellent at capturing shadow detail but very limited when it comes to recording highlights. In the field this means that I am most concerned about blowing out the highlights in an image. To deal with this, I adjust my exposure using the camera’s light meter and take a “test shot” as I approach the subject. I then evaluate the test shot’s histogram on the camera’s LCD screen. I want to make certain that the histogram does not extend past the right edge of the graph (indicating overexposure). If the histogram extends too far to the right, I adjust my exposure and fire off another test shot. Once I know that my exposure is correct and the histogram shows I am not cutting off the highlights, I can shoot without fear of loosing the image due to poor exposure. In the field, the histogram acts as an incidental light meter that shows exactly what the final image will look like.
Much has been said about the ability of digital to provide instant feedback and how this can speed up the learning curve for photographers who use digital. Personally, I find this to be one of the most overrated benefits of digital photography. When I am out in the field, I am there to take photographs, not review the images I already took. Yes, I review the histogram to fine-tune my exposure, but I hardly ever even glance at the image on the LCD screen as I shoot. My review of images is saved for the off hours when I am back in my hotel room. The simple fact is that for wildlife photography (the bulk of what I do) usually offers only a brief moment in which to capture the image. That means that I can choose between looking at the shot I just captured or try to get an even better one. For me, it isn’t an issue; shoot now, look later.
Once the shooting day is over, I still have the task of downloading the images from the CF cards. I am different from many other photographers in that I do not carry a laptop or digital wallet with me in the field. A 500mm lens and tripod is more then enough weight, thank you very much. I prefer to carry enough CF cards to shoot for the entire day, saving downloading to the laptop for midday and evening breaks at the hotel. This reduces the amount of equipment I carry in the field and circumvents the need to carry an extra power supply. Most importantly, by not downloading until the end of the day, I am able to focus all my attention on photography while I am in the field.
Downloading images can be done in three ways. The first time I downloaded images from my dSLR, I attached the camera directly to my computer and downloaded using the USB 1.0 connection. Forty-five minutes later the download was complete (using a one-GB card). To download seven cards using this method, it would take over 5 hours! Plus the camera is tied up the entire time so it can’t be used to take more pictures. Obviously, direct camera connection is not the best option for the serious photographer. The next step was using a PCMCIA card reader specifically designed for laptops. These cards as small and inexpensive and cut the download time of one card to 15 minutes. Better, but still not ideal. The best solution I have found is an external USB 2.0 CF card reader (Firewire card reader work equally well for MAC users). USB 2.0 is significantly faster then its predecessor, downloading a one GB card in a mere 2.5 minutes. Once all images are downloaded to the computer, they are placed in folder for review and editing.
One concern digital shooters must address is redundancy and a backup system for their field shoots. As photographers, we often carry backup cameras in case something goes wrong. Digital photographers must do the same thing when it comes to their digital workflow. Using a laptop as the method of downloading and storing your images is very convenient, but if the computer crashes, there must be an alternate method of downloading your digital images. The last thing I want to have happen is for my laptop to die on the first day of a three week Tanzanian safari, knowing I have no backup system in place.
The ideal solution is to carry a backup laptop. Of course, not many of us have the funds to purchase a second laptop and even if we did, weight is an issue. Fortunately, there are cheaper and better options. One alternative is to travel with someone who also has a laptop. That gives both of you a backup if something goes wrong with either machine. Just pack a number of blank CDs and you are covered in case of disaster. If you are traveling alone, a digital wallet like the Epson P-5000 might be the answer. Since I usually photograph alone, I have elected to carry a laptop and a small digital wallet for emergencies. Using the laptop is my preferred method, as it allows me to edit images during the evening, but the digital wallet helps me sleep better at night knowing that I have a backup system in place.