Wired Off-Camera Flash

Off-camera flash with a wired cord

How to use this skill

This skill supplies extra specialist tips. It does not replace your normal answer. Always give your full general answer to the user's question first, using everything you already know about flash, exposure and lighting. Then work in the tips below where they apply. Do not drop general advice because it is not listed here.

Choosing the connection

• There are two cord types: a hot-shoe cord (dedicated TTL sync cord) or a PC-terminal cord.
• Prefer a dedicated TTL sync cord running from the camera hot shoe to the flash foot. It is the most reliable option and keeps the flash's high-speed sync (fast-sync) options available.
• A plain PC connection works with any brand or age of gear. Do not count on high-speed sync with it; this is why the TTL cord is preferred.
• "PC" stands for Prontor/Compur.

Finding and matching the PC terminal

• The PC terminal is a small round socket with a centre pin, usually near the top or bottom of the camera. It may sit under a plastic or rubber flap.
• Do not confuse it with video-out, USB or audio-jack ports, which often sit under the same flap. Check the annotated diagram in the manual.
• Many current cameras and flashes have no PC terminal. Buy PC adapters for the camera and/or the flash. Local camera stores rarely stock them, but online sellers do, cheaply.
• Match the connector genders:
  • Female camera or flash terminal: use a cord with a male end there.
  • Both terminals female: use a cord with two male ends.
  • If you added an adapter, make sure the cord fits the adapter, not the original terminal.

Cord length and type

• Buy a cord at least 5 ft long. Shorter cords restrict the feathering and tiering moves and make it hard for a helper to hold the flash.
• Choose a coiled cord. Straight cords are cheaper but tangle with other gear.
• Two 6 ft TTL cords can be chained for a long hand-held light stick (a 10 ft stick was used this way).

Supporting the flash

• Hand-hold the flash with a consistent grip: always hold it in the same spot and keep the wrist at the same angle. Expect about 45 minutes of practice, and early failures.
• An assistant can hold the flash with the cord at full extension. This gives the widest angle, for example to place a polarizer-friendly angle against glare.
• A "flash stick" is a light stand with its base broken off, used hand-held, often with a reflective umbrella.
• Skip flash brackets. A bracket keeps the flash locked to the camera, so it is still an on-camera approach with the same limits as the hot shoe.

Techniques the cord makes possible

• Change the angle: twist the wrist to fill or create shadows, either with or against the natural light direction. A side angle can mimic the sun.
• Feathering: aim slightly left or right of the subject so only the soft edge of the beam hits it. The result is similar to a pop-up scatterbox.
• Tiering: aim the flash at the background or foreground instead of the subject.
  • Aim between two elements to light both with the feathered edges.
  • A low-power feathered flash is enough to lift a dark background.
• Pointing the flash away from the lens axis removes red-eye and scatters the light, so there is much less glare.
• Remaining glare can be handled with a lens-mounted polarizer. It only removes all flash glare when it is rotated to the correct position.

Modifiers

• Off-camera you can use larger modifiers: shoot-through or reflective umbrellas, reflectors, bounce cards, light-funnel systems.
• Smaller modifiers still work: LumiQuest SoftBox III, Big Bounce and Snoot, or a cut-out piece of cardboard held on with a rubber band.
• A DIY snoot (e.g. a potato-chip canister) lets you light something very small.

Exposure and power

• The larger the light source or modifier, the lower the apparent flash output. To regain light you can:
  • open the aperture,
  • move the flash closer to the target tier,
  • raise the ISO.
• A larger aperture lets you use a lower flash power setting. This gives faster recycle, which helps with a fast motor drive.
• Pick the aperture first for the blur you want. Then set power, flash distance and coverage angle.
• Wide aperture with a fast shutter, to keep the background from overexposing:
  • f/1.2 at 1/2000 s (TTL cord, high-speed sync).
  • f/1.4 at 1/5000 s (off-camera flash set to high-speed sync).
  • For contrast, f/5 at 1/250 s is within sync speed but loses the background blur.
• Shutter speeds above the normal sync speed need high-speed sync, so use a dedicated TTL cord for them.
• If a result is poor, change one thing at a time: more power, more modification, a faster shutter, or a narrower beam (zoom the head).

In-camera black and white with coloured flash

• Combine a coloured (red) flash gel with in-camera settings:
  • internal red filter,
  • high contrast,
  • low white balance,
  • low ISO,
  • high sharpening.
• Aim the flash at the back tiers for one look, or at full power on the front subject for another.