Capture refers to the process of taking your pictures and is the most self-evident phase in the digital lifecycle. There is a handful of choices to make from a workflow and file-handling perspective. These include camera settings and file/format options.
After your planning, the digital photography workflow really begins with the Capture phase of the lifecycle. While most of the decisions you make here relate to the subject matter and aesthetics of the image, there are some file-handling choices to make as well. In most cases, the scope of these decisions is limited by a small number of options offered by the camera you use.
DSLR cameras typically offer a choice of format for how you save your image files. They can be saved as raw files, with minimal processing by the camera. They can also be saved as JPEG files, or in both formats simultaneously.
In most cases, class="trademark">® recommends shooting in raw, if possible. With raw capture, you preserve the maximum color and tonal data. Of course the files will be bigger, and the downstream workflow requires software that is capable of working with raw files, but those are typically acceptable trade-offs for the benefits raw capture provides.
Sometimes, it is advantageous to set the camera to save a JPEG rather than a raw file. This can be true if the assignment calls for immediate delivery of files, and does not allow for processing raw into a derivative format. It may also be true for circumstances where the volume of photography is so large that raw files are impractical or even impossible. This may occur in very large event photography, or in long time-lapse sequences, or in large HDR/panoramic stitching projects.
Raw + JPEG
Most cameras that shoot raw offer the option to save both a raw and a JPEG at the same time. In the past, this was seen generally as a workflow aid, since software to view and work with raw files was slow. The speed of modern computers and modern software make raw+JPEG shooting much less necessary. In fact, shooting raw+JPEG generally serves to slow down and confuse workflow now, except where there is a defined need for dual capture. In most cases, the only real need for dual format capture is a requirement for immediate delivery of image files.
Some cameras also offer a TIFF setting as a capture format, but this is typically undesirable to use.
You have a handful of options for image settings that will make a difference in how the image file is created. Some of these apply mostly to JPEGs, and some of these apply only to raw.
White balance is a measurement of the color of the light illuminating a scene. Your camera (for JPEG files) or your raw file processing software (for raw files) uses this information to interpret the color in the captured file, and turn it into a natural-looking color rendition. In a JPEG file, this interpretation is baked into the color of the file. In a raw file, white balance is a metadata tag that can be used (or not used) when the file is processed.
The white balance setting you choose is extremely important if you are shooting JPEG, since the white balance determines which color information is thrown out and which is retained when the JPEG file is created. If you set you color balance improperly (using a daylight balance for tungsten illumination, for instance), it may be nearly impossible to create a natural-looking photo from the capture. It’s essential to set a good color balance when shooting JPEGs or movie files.
Some cameras will change how the raw data is recorded in the raw file depending on the color balance setting. Nikon cameras, for instance, will boost the blue channel when the color balance is set to a low color temperature, altering the way the raw image data is saved. If time permits, it’s always advisable to create a custom white balance for any particular lighting setup by photographing a color-neutral object and letting the camera compute a white balance setting.
Most digital cameras offer a choice of color profile as part of general file settings. Typically this includes sRGB and Adobe RGB. This setting only applies to in-camera JPEG files, and does not alter the color in the raw image at all.
Shooting in Adobe RGB will offer a slightly larger color space, which includes a larger number of colors. This can provide a better color range, particularly for blues and greens.
The sRGB color space is smaller, but may be better suited to some uses, particularly if the in-camera JPEG is going to be delivered with no additional post-processing. Web display and minilab printing will generally look better if the JPEG is in the sRGB color space. This is especially true if the printer or display does not make use of the color profile tag.
The bit depth refers to the number of steps from white to black in a file. The higher the number, the more middle steps, and therefore the more color information is captured. Digital cameras save 8-bit color when shooting JPEG, and a larger bit depth for raw files. Most DSLR cameras capture in 10- or 12-bit color for raw images, and some offer increased bit depth of 14 bits. Medium format digital camera backs typically shoot in 16 bit.
Higher bit depth should offer extended highlight and shadow sensitivity. While we have found that to be true for medium format backs in general, we have not seen a great deal of difference between 12- and 14-bit capture in DSLR cameras. Higher bit depth makes for a larger file, but may not pay off in any increase in quality.
In addition to white balance, color profile and format, there are a handful of other file handling options that most digital cameras offer. These include custom file prefixes, file numbering options and folder options.
Digital cameras limit the naming options to no more than eight characters plus a three-character extension. In most cases, current cameras give you control over the first three characters in the name, as well as the placement of an underscore. (The placement of the underscore is often related to the color profile that is chosen. It will come prior to the -three-character identifier for sRGB files and after the three-character identifier for Adobe RGB files.)
Many photographers choose to customize the three characters to their own initials, or to some other setting that can help them distinguish between multiple camera bodies. While this can be helpful to some degree, keep in mind that class="trademark">® recommends renaming your image files, so this information is often lost in the rename process.
Cameras often offer a choice in how file numbering is handled. There are two typical options, and each method has its advantages:
Always reset for new card
In this method, the numbering always resets to 0001 each time a new media card is inserted.
- This makes for a cleaner set of file names, if you are very disciplined about how your use of cards correlates to each shoot that you do.
- It can offer increased possibility of file name duplication, particularly for multi-card or multi-camera shoots.
Numbering may be allowed to run continuously, resetting once the count reaches 9999.
- This can reduce the possibility of name duplication.
- It can be a little harder to read, since each shoot will be starting on a random number.
Digital cameras will always put images inside a folder (or maybe several folders) on a media card. Your camera may offer several different options for how these folders behave. You may be able to create custom names for the folders, and you may be able to limit how many images can be in a folder before a new one is created.
You’ll want to make sure that you create a standardized way to handle your media cards that keeps the cards well protected and lets you make an orderly workflow for download. Here are some tips for media card handling.
- Make sure that your memory cards are protected from loss and physical damage by using some kind of card holder to store them.
- Standard SD cards are significantly more fragile than Compact Flash cards.
- Have a plan for keeping shot cards separate from un-shot cards.
- Make sure that the un-shot cards are formatted and ready to go.
- Establish a numbering or coding system for your cards. If you find corrupted files, this will make it easier to track down which card may be creating the problem. It also just helps you keep track of your cards.
It is increasingly common for digital cameras to include more than one media card slot. There are three general ways these additional slots are used.
File type targeting
If the you are shooting more than one format with the card, it may be best to target a particular file type to a particular media card. When shooting stills and movies, the stills can be targeted to one card, and the movies can be sent to the other one. This can make downstream workflow easier, since it’s common to create different workflows for each media type.
Likewise, someone who needs to shoot raw and JPEG files for a rapid delivery can accelerate this workflow by writing each file type to a separate card. The JPEG card can be downloaded quickly, without having to wait for the larger raw files to transfer. Raw files can be downloaded at a later time, and can enter a workflow pipeline that does not get confused by the commingling with JPEG files.
Dual media card slots can also be used to increase the memory capacity of your camera. The camera can be set to record to one card until full, and then switch over to the second card. With the inexpensive availability of very large media cards, this capability is less attractive than it once was, except for specialized high-volume capture scenarios.
A second media card slot can also be used to create a second copy of the files, which can provide backup in the event the first media card fails. This can be attractive if you need to hand off cards in the middle of an event shoot, or if the shoot is a one-of-a-kind event of very high value.
Not all digital photography makes use of a media card. Sometimes the camera is connected directly to the computer by USB or Firewire cable, or even through wireless networking. Images are immediately transferred to the computer as they are made. Tethered capture is particularly useful for product and architectural photography where the subject matter does not move. Tethered capture is also popular in high-end fashion and advertising photography where a larger creative and technical team is a normal part of the process.
Tethered capture is particularly attractive because it makes very detailed inspection of an image available right away. The computer can display the image at full resolution on a large screen, which provides a confirmation of critical focus issues. And tethered capture can load the image into raw conversion software, providing precise information about the exposure.
Card, tether, or both
Some cameras can only transfer files to the computer when tethered, and can’t write simultaneously to the media card. For these cameras, tethered capture can be a little more risky, since a loose cable or other problem in file transfer may result in the loss of the files.
Canon cameras provide the ability to do a tethered transfer at the same time as files are written to a local media card, providing a backup of the file.
There are an increasing number of ways to transfer images immediately from the camera to a computer using wireless technologies. This feature may be built into the camera, or it may be provided by an optional accessory, or it may even be provided by a special media card such as the Eye-fi card. While wireless transfer is not really tethering in the traditional sense, it does allow images to show up on the computer without the traditional download process.
Wireless transfer methods may be insufficiently fast to transfer an entire shoot of raw files at an acceptable speed. Most wireless transfer tools let the user choose to transfer in-camera JPEG files only, or to select which images to transfer individually.
The Eye-fi card also allows the user to upload image and movie files automatically to web publishing services directly from the camera.