EFP – Technology

Hey Buddy, You Need A Light?

Where It Goes

In Camera Flash

This is what your smart phone has. Some P&S (point and shoot) cameras have a flash built into the upper-left (typically) part of the camera. You get a flat-looking, red-eye creating light.

An improvement is a pop-up flash. It places the flash head slight further from the lens and this could result in slightly better lighting on your subject along with slightly less red-eye.

In both cases, the flash is sucking power from your camera’s battery.

Some of the issues you might have, especially with in camera flash:

  • Red Eye – because of how the light reflects off of the back of the eye, you can have red from its blood vessels visible through the eye’s lens. Looks demonic. Needs to be fixed in post, most often. The flash, being so close to the camera lens, makes this happen.
  • Flat Light – with a straight on flash, you can end up with flat, shadow-less and  uninteresting results. Light is capable of so much more.

On Camera Flash

Better than in-camera. An on camera flash has its own batteries. You can turn it into an off-camera flash using a cable (or wireless radio). The flash head is about six inches from the lens, which improves the lighting slightly and reduces red-eye (even more than a pop-up flash can).

Without a light modifier, the shadows created by this flash can be harsh. This is true for in-camera. However, when the camera is oriented for a simple horizontal photo, the shadows tend to fall down and behind the subject. They are less noticeable.

Turn you camera to the side for a vertical shot? …ugh. The shadows now weirdly come out from the side of the subject. Other than sunrise and sunset, you don’t see this in the natural world all that much. Side-shadows look awful. This is why off-camera is so much better.

Off Camera Flash

What’s the ideal spot for a flash when used with a typical camera? A safe bet is about a foot above the lens. The light starts to mimic what a beauty light would produce. (Some may argue about this. They are right in the details, but I’m talking broad strokes here.) You get shadows that drop off in a natural looking way (think afternoon sun behind you when you photograph someone).

If you switch to a vertical shot, you have to have a way of moving the flash so that it, again, is above the lens.

You can handhold a flash using a cable to connect it to a camera. This works great as you can make multiple photos varying the flash position (left, right, up, down). You have different effects with shadows. Fun stuff. This works for either horizontal or vertical.

The downside is that it’s cumbersome to do this for more than a few shots. It’s better to have some kind of bracket to hold things together with a swivel to handle the horizontal/vertical thing.

Brackets vary in features and price.

Brackets

Cables

Triggers

Speedlights

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Check Out Explora Article

So, Speedlight is a Nikon thing. I don’t know if it’s become generic in the way Kleenex became what a facial tissue is. The sense is that most folks understand that speedlight means electronic flash. It’s so way cooler sounding. B&H Explora has a nice article: A Speedlight Buyer’s Guide.

Manual

A simple design: battery, capacitor, discharge tube circuitry. You have a dial that tells you how to set your camera for whatever working distance you have. (That is, distance from flash head to subject.)

Simple.

You could almost do this on autopilot if you practice enough.

Auto Exposure

Auto exposure inside of a speedlight means you have a bit more flexibility in how you approach shooting. Now, you don’t have to look at the control dial for each time you change your working distance. The “eye” will make sure the speedlight puts out the right amount of light by reading the scene. The only thing you have to worry about is that your are positioned within the working distance as indicated on the dial. (You may have to be from 6-12 feet, for example…the dial would tell you that.)

TTL

In this mode, the speedlight gives up control of the discharge to what the camera sensor say it should be. A high-end in camera system (like Nikon’s Matrix) takes into account many variable as it sets/reads exposure. This was all created to make the photographer’s life easy. In some cases, though, not knowing all the technical stuff going on in the background could be a detriment. It’s good to dig in, study what’s really happening.

Why?

Simple, if multi-flash settings (like a studio shoot), you may need to know to get things to work. You should be in control.

Strobe

Some speedlights produce a strobe effect. It where multiple flashes are produced during a single exposure. You can get some nice trick shots.

Stobe Effect
Model Light

A high-end studio strobe usually comes with a separate light, a modeling lamp. You turn it on to see how the strobe’s light will fall on the subject. Speedlights don’t have this. To accommodate those times when you wish you did, you may find a modeling light feature on your strobe. Basically, it pulses mini-flashes constantly. Your eye integrates these and your brain sees what it’s been tricked into thinking is a constant light.

Can kill batteries if used a lot.

High Sync Speed

There are various kinds of shutters. In still photography, the common ones are leaf and focal plane. A leaf shutter lives inside of a lens and is made up of concentric leafs that open and close fully for each exposure. They usually top off at 1/500th of a second. What’s nice about these is that with a flash, you can use any shutter speed. Sometimes, to control ambient light, you would want to use a high shutter.

A focal plan shutter can go much higher than 1/500th. That’s good for when you are out and about and shooting in bright conditions. Put a speedlight onto you camera and you have a problem.

Why?

The focal plane shutter, typically, will full open and close at speeds from very slow (1 sec) to about 1/200th. (Older, cloth shutters were slower than that…maybe 1/60th.) To get a speed higher than 1/200th means the curtains have to create a traveling slit. (Look it up if you really want to know.) The problem with a traveling slit and a speedlight is that, if you fire the speedlight during a traveling slit exposure, only the part where the slit is open will see the flash. This is not good.

So, focal plane shutters usually had a limit for electronic flash. It would be the fastest speed where the focal plane curtain was fully open.

How can we fix this problem?

Camera and flash designers figured out that they can fire the flash using a strobe effect. If you have a shutter speed of 1/1000th, for example, the traveling slit may be only a quarter open at any time. If you have a very high frequency strobe effect going, and it operates for the full 1/1000th second, then each quarter size slit will be pulsed with, more or less, the same number of strobed pulses.

This works. You may not get the full output potential of the flash in such cases, but if the shoe fits.

Firing

Setting off your speedlight.

Radio

Radio controlled systems can have a transmitter and receiver, or a combination unit that can be one or the other. Prices vary and it’s likely you get what you pay for.

Interference with other photographers using the same systems is possible. (Think sporting events.)

These systems are not line-of-sight. You can hide them from view.

Government regulations apply. There are specific rules about frequencies, power levels, and so on. Expensive units will likely comply. Inexpensive units? Hmmm.

If you are planning on international travel, you may find that you are not allowed to use a particular radio-based system. Look it up if you are not sure.

Elec Eye

Some flash units have sensors that detect when another flash fires. It then can be set up to slave itself off of that flash and fire on its own.

Some wireless triggers use light instead of radio waves. This is usually in the infrared range (so humans aren’t bothered by these discharges). This type of slave is different from a standard slave (above). Typically, there is an infrared transmitter, similar to a radio unit, that attaches to the camera. These systems are line-of-sight. It’s possible to hide such units, but they’d need to be able to see the reflected infrared light in some way.

System Specific

Newer designs in flash system families use specially encoded light pulses that facilitate the pre-flash communication between speedlights. These systems allow you to create banks of light, and control the lights from a single master.

Two thoughts. Practice. And look it up.

Wired

There are different wiring mechanism for connecting lighting components. These will be specific to whatever system you are using. We won’t cover this here.

So, why mention it.

The PC connector.

That’s why.

Photographers have suffered with a flash connection technology called the PC connector. It’s horrible. It’s been around for a long time. It’s horrible. Many cameras still have them. It’s horrible.

Why might one not like a PC Connector?

The don’t create a strong, reliable connection. If you look at one of these things, they are delicate, can easily pop off, and are prone to poor connectivity (bent pin, corrosion).

Also, depending on the camera and flash, they could fry your system.

A lot of cameras don’t use these anymore. Instead, they have connectivity through a hot shoe. If you must have a PC connection, get an adapter that lets you attach your PC cable to it, then mount it on the camera. Better yet, make sure you buy an adapter that protects for high voltage discharges that could fry your camera’s electronics.

Or, even better, invest and go wireless.

Shutter Speed Considerations

This is kind of covered above in High Sync Speed…

“There are various kinds of shutters. In still photography, the common ones are leaf and focal plane…”

Focal Plane

A focal plan shutter can go much higher than 1/500th. That’s good for when you are out and about and shooting in bright conditions. Put a speedlight onto you camera and you have a problem.

Why?

The focal plane shutter, typically, will full open and close at speeds from very slow (1 sec) to about 1/200th. (Older, cloth shutters were slower than that…maybe 1/60th.) To get a speed higher than 1/200th means the curtains have to create a traveling slit. (Look it up if you really want to know.) The problem with a traveling slit and a speedlight is that, if you fire the speedlight during a traveling slit exposure, only the part where the slit is open will see the flash. This is not good.

So, focal plane shutters usually had a limit for electronic flash. It would be the fastest speed where the focal plane curtain was fully open.

Leaf Shutter

A leaf shutter lives inside of a lens and is made up of concentric leafs that open and close fully for each exposure. They usually top off at 1/500th of a second. What’s nice about these is that with a flash, you can use any shutter speed. Sometimes, to control ambient light, you would want to use a high shutter.


Hey, we’ll get to these topics over time.

Brackets & Stands

Booms

Mono vs Power Packs

Backgrounds

Stools & Apple Boxes

Sand Bags

Modifiers

Filters Or Gels

Color Correcting

Mood

Softening

Diffusers

Reflectors

Parabolic

Snoot

Beauty

Tents

Polarizers

Flags

Tape, clips, foil, scissors, etc.

Power

Output

Watt-Seconds Versus Guide Numbers

Guide Numbers

Watt-Seconds

Light Falloff

Pen-Umbra

Distance

Input

Batteries

AC