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

• Does the software application have camera controls?
• 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 USB2 connections than with Firewire. The trend seems to be towards USB2 for newer cameras. This means that tether transfer speeds becomes significantly slower for cameras with USB2 cables connected to Mac computers. Knowing this, some have taken advantage of the dual boot capabilities of Intel Macs to run a Windows partition for tethered capture. Others have invested in a Windows laptop for tethered shoots. This is probably a temporary situation, as Apple seems to be withdrawing support for Firewire in favor of USB2. USB3 is in development and, when available, may make this whole discussion moot.

Wireless connections are also possible. Currently, slow transfer speed and finicky set-up have resulted in limited adoption. Wireless will undoubtedly become a viable option soon.

Canon has just introduced a wireless file transmitter for the Canon 5D MKII which allows you to wirelessly transfer the photographs from your Canon 5D Mark II to a Wireless LAN Access point or straight to your computer. The most interesting aspect of this device is the option to shoot tethered via one gigabit Ethernet which allows for data transfer speeds of over 150 MB/s. Compare this to Firewire 400’s 50 MB/s or Firewire 800’s 100 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 raid1 device. Another possible solution is to daisy chain portable drives and use the operating system’s software to configure the two drives as a raid1 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. The disadvantages are that file transfer times can be on the slow side, depending on the file size, the efficiency of the software, the connection type, and the speed of the computer being used. Laptops are often used for this function, and they are not as quick as desktops, being more limited by having less processors and less horsepower overall. There is also the factor of USB connections being somewhat faster on Windows OS machines, and Firewire being faster on Mac OS machines. High speed Ethernet or USB3 connections, as well as support for multi-core laptops should help out with these issues as time goes on.

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 RAID1 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 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 out 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.

The Hybrid approach

An approach used by many is to use the camera maker's software in combination with PIEware. Since Adobe Lightroom is a popular PIEware application that can be used this way, we will show you the workflow steps.

Step One:

Connect the camera to the computer with the USB/FireWire/Ethernet cable. If your camera only supports USB, you may need to get a USB extender cable with a repeater module built in.

Step Two:

Download and install the manufacturer's software that allows the computer to recognize your camera. We will show screenshots from Canon EOS Utility. Other manufacturer's software has similar features.

Figure 2 Canon EOS Utility setup with camera controls showing. Notice that we have checked the option to save the captured images to the camera's memory card as well as transfer them to the computer.

Figure 3 Normally EOS Utility software is linked to Canon DPP (Digital Photo Professional) software. You might think that you should select Lightroom here, but actually you need to select none in order to trigger auto import without seeing the import panel each time you make an exposure.

Step Three:

Create a folder on your computer. We usually put this folder on the desktop and label it "Capture". Then configure the capture utility software to use that folder as the destination for the transferred files.

Figure 4 Canon EOS Utility needs to be configured to transfer the files to the folder you have set up to receive the transferred files.

Step Four:

Once the camera is connected, and the capture utility software is up and running, open Lightroom and go to File>Auto Import, and click on Enable Auto Import. Next configure the File>Auto Import Settings to find and select the "Capture" Folder. At this point, you are all set to shoot. All you need to do to see them in Lightroom as you shoot is to select the subfolder name in Folders dialog on the left side of Lightroom's Library module.

Figure 5 Select the watched folder, which in our case is called "Capture". This dialog box is where you can add develop settings, add basic metadata, and even keywords if you want.

Step Five:

Once the captured images come into Lightroom, you can go to the next workflow steps. Oftentimes, clients may wish to make image selections at this stage. Lightroom has star ratings and labels that can facilitate this process. Be sure to save the metadata to the file (Library module>Metadata>Save Metadata to file) so that your editing work with ratings and labels, as well as any additional metadata you might have added, will stay with the image file when you transfer the folder to your regular workstation back at the studio.