Tethering: camera to computer or screen
By MidgePhoto, written 1529889416.
Most DSLR and Compact System Cameras provide connections for a computer and/or a display screen, and some can do this wirelessly. Functionality mayinvolve control and file transfer or merely display.
Models find feedback useful. In the studio this may extend from a mirror handily placed, through occasional looks at the back of the camera to a large screen placed where the whole crew can see it, showing the images in real time and replay, which can be effective.
In a large production there might be a creative director (or others) outside the studio, in the same building or far away, which may be connected by a network. They would find it useful to be able to flick through the collected images without interfering with the current one and import selected ones into editing software, etc.
A potential downside to use within the studio - or other location - is that both model and photographer may find themselves pausing and viewing the screen excessively. Discipline is necessary and should be sufficient to deal with this.
Wired connections, such as USB or HDMI cables, may fail by being pulled out by camera movement or tripped over, and might damage the cameras it departs. Mini-USB sockets are probably more at risk of this. The camera ports are delicate and expensive to repair. Strain relief - securing the cable very firmly to the camera so that a pull on the cable does reach the port - is highly desirable. Clamping it to an Arca Swiss type plate or a cage works well. The wires are also another piece of clutter to fall over.
Wireless connections are becoming mature. No additional software is required to simply plug a TV or other HDMI monitor in to the camera.
In order to control the camera, beyond stepping through the images on the card, some form of computer and software are needed Modern software should operate however the connection is made, but not all may.
The manufacturers commonly provide a utility for operating the camera, with Canon's DPP Camera Utility and Camera Connect being examples. These are likely to work well and be effective, but may not run on all operating systems and devices. Various third party software, some of it open source, is available.
A useful effect of tethering is the immediate creation of a backup copy of files otherwise only held on the camera card(s). This is usually configurable.
The hardware choices are: a TV screen, a computer monitor, a tablet, or even a mobile phone. An interesting project is to provide a feed to an arbitrary number of devices of various sorts.
For Canon the software provided with the camera at no extra cost - Canon Utility and DPP - works well. Other brands have similar software.
The Open Source programs DarkTable and Entangle are effective, are developing steadily, and in the case of DT do much besides. Also at no extra cost.
Several other well-known programs can tether in addition to, or as their main function.
Beyond the hardware, questions of whether to use tethering at all, or when, or how are more interesting, and neither are likely to enjoy consensus.
Being explicit about the risk of excess attention and time on the screen, doing the light-test and looking at it, then shooting a series of images, then looking again - each time with the model - seems to work. Arranging the screen so nobody can see it normally, or so that it is visible only to the creative director or others, are options.
Marking cables with scraps of bright tape, adding them to the list of hazards to rehearse warnings on during a studio session (at least with new people) and being careful about the run of the wires are all desirable safety features.
Taking advantage of the backup afforded by having the computer, download each image as it is made will slow the process. If that becomes visible then only downloading the JPEG while leaving the raw file as only one copy on the camera card is a compromise.
Actually clearing the images off the camera card as they are downloaded, or setting the camera not to record to card, seems an unnecessary hostage to fortune in an era of large cards.
Tethering over the Internet
Actually running the tethering program - DarkTable or Canon Utility or whatever it may be - over the Internet may be inefficient and fragile. Remoting the desktop is possible, and routinely used in many situations. An efficient remote desktop only moves the changes in the desktop, and the keystrokes and mouse movements, while the high bandwidth communication with the camera stays in the room it is in. It also allows cross-platform working, if you choose wisely. VNC - Virtual Network Computing - was the first and is still good, and operates between at least Linux, Windows and OS/X in any combination. Moving the resulting files needs thinking about, but isn't hard.
Pointing the camera over the Internet would be more ambitious, needing a motorised tripod head or robot arm. A voice connection to ask someone to move it is probably this year's achievable aim.
References, useful sources, and further reading
Useful (and fairly comprehensive) software list available athttps://www.tethertools.com/tethering-software/
Revised 2019 November. Addition on remote tethering in the plague year, 2020 April