Tethered Capture

Tethering with video out

The advantage of using the video out for tethered shooting is that the images display on the external monitor as quickly as they do on the back of the camera. These images are the camera-generated JPEG previews, so they are "camera processed" and have whatever white balance, tone curves and sharpening that you have selected in-camera. They are not being transferred to the computer, so they will have the in-camera file naming, and the only way to review what you have shot is to scroll through the shots using the camera's display menu. Vertical images will either appear sideways on the monitor, or as smaller vertical images in a horizontal frame if your camera supports rotating the vertical shots. Since the actual files are not being transferred, none of the workflow advantages of applying metadata, file naming, or applying image adjustments can be realized.

Tethering with file transfer to the computer

While tethering using video out is fast and uncomplicated, tethering with file transfer to the computer offers many advantages you can't get with video out. These include ingestion options such as file renaming, embedding metadata and, perhaps most importantly, it allows for more accurate and detailed previews since the actual high resolution files are processed and displayed. 

Here are some important considerations for choosing which tethering hardware and software to use:

• Does the software application have camera controls?
• What is the transfer speed?
• Can parametric image presets be applied?
• Can metadata be applied?
• Will the files be written to both memory card AND disc?
• What might happen to the images being transferred if the camera connection is interrupted?

When shooting tethered, there can be a speed difference due to the operating system (OS) and the connection type. The camera manufacturer’s software for Mac computers can be slower with USB 2 connections than with FireWire. The trend seems to be towards USB 2 for newer cameras. Wireless connections are also possible. Currently, slow transfer speed and finicky set-up have resulted in limited adoption. Wireless will become a viable option soon, as will USB 3 and Thunderbolt connections, undoubtedly.

Canon and Nikon both offer, wireless and wired transfer of files, sometimes through the use of additional accessories that hook onto regular Ethernet . Wireless transfer is slow, usually achieving no more than 15 MB/s, but it offers convenience and freedom of movenment.  The most interesting aspect of this device is the option to shoot tethered via gigabit Ethernet. which allows for data transfer speeds around 100 MB/s. Compare this to Firewire 400’s 40 MB/s or Firewire 800’s 80 MB/s. Gigabit Ethernet would also break the 30 foot limitation of FireWire cable by allowing tethered shooting at lengths up to 300 feet.

If shooting tethered, set the software preference to save image data to the camera card as well as transfer it to the computer or hard drive.

If the tethering software doesn’t give you the option of simultaneously capturing to card and computer, be aware that you are risking data loss. The best solution is to send the data to a hardware driven RAID 1 device. Another possible solution is to daisy-chain portable drives and use the operating system’s software to configure the two drives as a RAID 1 volume. This solution will write data slightly slower than a hardware driven RAID. If that set-up seems too complicated, you can simply use a back-up utility to sync the two portable drives.

Figure 1 Canon EOS Utility preference panel for remote (tethered) shooting indicating that image data will be saved to the camera memory card as well as to computer disc.

Using manufacturer's software

Most camera makers offer dedicated tethering software using USB, FireWire, wireless or Ethernet capability, which does transfer the image files to the computer. Most of these systems include camera controls and the newer cameras have live view — which is a live video feed from the sensor. Having camera controls is a major convenience, as is live view, which can aid in critical focus and remote viewing if the camera is placed somewhere that makes using the viewfinder difficult or impossible. This can be a great advantage for many, including architectural photographers trying to position the camera in tight spaces. 

Some manufacturer's software supports writing captured images to the card as well as transferring them to the computer. We feel strongly that writing to the camera memory card is an important fail-safe feature. If your camera/software doesn't support this feature, you'll need to be extra vigilant about maintaining a secure connection to the computer, and possibly implementing a mirrored RAID 1 set-up, or an automatic back-up script that causes back-up software to copy the transferred files to a back-up drive on a regular basis. Phase One cameras and software don't offer the option of writing to the camera card and to the computer at the same time, but they do have the feature that allows the camera to begin writing to the card if the connection to the computer is broken. While this does save you from losing files, it does create a situation where you will have to sort out which files are on the computer, and which files are on the card.

Using third party software

Some PIEware such as Adobe Lightroom 3, Apple Aperture and Bibble have direct tethering functions, as does Phase One Capture One, which tethers to cameras other than Phase One's own brand. Since there is no official standard protocol among camera makers for tethering (surprise!), and not all camera makers publish their API (application programming interface), third party software doesn't support all cameras, and often doesn't provide camera control features. Still, many workflow steps such as metadata, file naming, adjustment presets, and folder organization can be accomplished with these software applications. You'll need to check on whether these software applications allow the images to be captured to the camera's memory card as well — in our testing, we found that most don't, so you will have to either live with that risk, or institute a RAID 1 or back-up script as described earlier.

Tethered shooting using Adobe Lightroom 3

Unlike previous versions of the program, Adobe Lightroom 3 includes tethered shooting as part of the program. Unlike other programs that support tethering, Lightroom 3 records the images to the camera's card as well as the computer's hard drive whenever the camera maker's API supports it. Currently, Canon does, but Nikon does not. Lightroom 3 currently supports tethering with most Canon and Nikon cameras. You can find a full list of supported cameras here.