Heres what you need:
- DSLR with manual flash
- Tirpod with Fluid or Ball or Gear head
- Flash modules and radio triggers
- Soft box
- shoot through umbrella
- light meter
- light stands with boom arms
In camera metering systems are useless when working with flash. In camera meters are reflective meters that use TTL or Through teh Lens metering. It is eaily fooled by reflective objects, or very dark or very bright scenes.
Your camera can meter the flash, but only when connected to the hot shoe. The camera tells the flash to send out pre-flash signal, with set brightness, that is interpereted by the camera to determine metering, factoring in ambient llighting and flash. These are called TTL flashes.
TTL flashes are known to cost much more than manaul flash, also called dumb flashes. And when you want to add multiple TTL flash modules, the cost skyrockets! Manual speedlights and strobes are much more cost efficient, but take a lot of guesswork to get the setting you want. Light meters solve this.
Light meters allow for incident light metering. We will use it for all product shots. The difference between reflective light meters (like your camera) and incident light metering is thus:
- Reflective Metering – Determine the relative intensity of light bouncing off a subject
- Incident Metering – Determing the relative intensity of light falling on a subject
Incident is more accurate than reflective because the reflectiveness of the subject doesn’t matter, only the amount of light falling on the subject. Its also better because it can meter the flash.
When placed in flash metering mode, the light meter waits for a flash input, then responds with the measurement of that flash pulse and waits for another one.
Another way to measure flash is with a PC sync cord, if allowable by the light meter you are using and your flash module. Connect your meter to your flash and have the meter fire the flash to measure it.
To get basic exposure, follow these steps: Compose scene, turn on light meter and set to flash metering mode. Change camera settings to those given by the light meter (it’s best to start with a low ISO (100) when working with flash).
Set the flash, put the light meter in the subject space pointed towards the lens and hit measure. Then hit test on the light module, or take a picture.
You will be given back an F-number, representing the proper aperture for a good exposure given the readings from your light meter.
Should you want to use a more open aperture, you would need to turn down the flash intensity. If you want larger depth of field, you would need less intense flash, or more diffuse flash.
Light meters also measure ambient light!
Advantages and Disadvantages of Flash vs Constant Lights
Output – Speedlights have higher intensity, giving rise to more lighting modifiers and possibilities. Constant lights, which include flourescents, LEDs, and incandescent lights, have much lower output.
Incandescent lights create too much heat. This high power allows for the use of small apertures (large depth of field) without the need for ISO increases (constant lights often require ISO)
Sppedlights often offer highly flexible output, whereas studio constant lights can offer changes (as much as a few stops) but are known to become expensive.
Flash is a hard light source, which can be made softer. Flourescent and LED panels are soft by nature, so making them harder requires moving them back, which isn’t always possible. Going hard to soft is easy with modifiers.
Flourescent and LED’s have lighting issues, while flashes have consistent light color and quality.
Flash is lightwieght, while constant is relatively more heavy.
Speedlights and Strobes
Speedlights are battery powered flash that uses hotshoe mount. Speedlights use guide number to determine max output, which is distance expressed over f-number. So, if subject was 17ft away, you would need f11 to get proper exposure, whereas if subject 150ft away, you would need f-1.4.
Studio strobes offer much more power. There are two types, a mono light and pack and head. Mono lights have power supplies and controls on the flash unit. Pacak and head have flash head and separate pack with controls for the head (and multiple heads, if necessary).
Studio strobes have modeling lights, which show what light will look like when flashed. As flash increases, modeling light increases.
Recycling time, with full batteries, is short in speedlights, but can be almost nonexistant for strobes. Be careful, though, you can easily overheat and melt your bulb or circuits.
Modifiers are easier to find for speedlights, as strobes are proprietary and each one has different, so you have to buy adapters.
Both are great! For product photos, you will use speedlights most of the time, but both are versatile. Starting out, if you are only working in studio, get a manual speedlight. If you might go outside, get one TTL speedlight and 1 more manual. Once you are good at using those, get a strobe to finish out your set.
Remotely Triggering our Flashes
Triggereing can be done in three ways:
Optical triggering – if sensor sees a flash, it fires. They are very fast, so won’t have many sync issues. As long as you have control over the built-in flash unit, this method should work well for you. If you can’t control flash in camera, then when you try to use built-in flash, camera will fire pre-flash for metering and you will trigger your slave flash, throwing off your image.
Some speedlights can ignore pre-flash, so consult your operating manual!
Another option is to set up off-camera flashes in optical slave, then place flash module in hot shoe and turn down the flash so that youa re not affecting the scene, only firing the remote flashes. The flash module on your camera will not fire preflash, so this is good wok around.
You can also use radio triggers. Some speedlights have built in radio receivers, so look out for functionality. If using mixed flashes, get an inexpensive option for radio triggers.
Radio triggers can be optionally switched between receiver and transmitter, they are transievers. They can also connect to camera and cause it to take a picture with any other connected flashes. This allows you to move around iwth your light meter and test fire your connected flashes, then when you have things the way you want, you can fire your camera shutter and the flashes, remotely capturing your image.
Lastly, you can use PC sync cables, which fire the flash upon shutter. You can also attach the PC sync cables to your radio transmitters, to fire flahses that don’t have a hotshoe (studio strobe). You can also connect individual flashes with PC sync cables.
Lastly, you can find optical triggers that have PC sync ports, so they can watch for flash and fire a light, giving even more versatility.
Getting the Shot
Get lighting support system and paper backgrounds. Be sure to put sandbags on sides of crossbar to keep crossbar straight and not sagging. paper backgrounds have a tendency to sag and bow due to the weight, the sandbags will help prevent this.
Fabric backgrounds are great, but they tend to wrinkle, so have a steam iron on hand!
Try to get into space that allows you to control reflections. The darker the walls, the better for controlling how light moves throughtout he scene. Try to flag off light that you don’t need for your scene.
Having a nice flooring can help provide a professional touch. Laminate floring at HD or Lowes can be spread across the table for a great look at ta low price.
Now, place your subject on your surface in front of your background. Center your camera on the camera and compse the shot. Choose your settings based on how you want the shot to look.
To choose your shutter speed, find the fastest speed you can go until you reach full black, without the flash. This means your camera shutter is blocking out all ambient light. Now, only the light from your flash will be used by the sensor to expose the scene.
F-Number is an artistic choice. For product shots, usually go between f8 through f10 so the entire subject is sharp without the background bothering the subject.
On APS-C style camera, due to it’s cropped image, the further depth of field you can achieve is f11 without some kind of diffraction on the subject, making the image look softer and less crisp.
Always start with a low ISO of 100, especially when in studio, to prevent any possible noise.
Now, place your light to get the desired direction. Using your light meter, move your light closer or further until you get the desired fNumber for the given shutter speed (that destroys ambient light).
This will result in a contrasty, but fun, image that might be too dramatic for most commercial projects. Use a fill to bring down the shadows and offer a more pleasing image.
The closer you get your fill source to the subject, and the bigger the fill, the softer the light will model the subject.
Now, you’ll wan to light the background. Place the light behind and underneath the subject. You are attempting to create a vignette on the background behind the subject, so move the light around to where you can’t see the light, but can see the light spot on the background, behind the subject.
If you need to color the backgournd, use a gel over the background light. You need to know the power of the background, so take a light meter of the backgorund light output. Then place the gel over the light and increase the output until the light meter is the same before the gel.
Some gels are known to drop the power of the light to as much as 4%, a huge reduction!
Play with the highlight and fill relative intensity by increasing or decreasing the power of your key and fill lights, respectively. Use different power ratios for different levels of drama.
Once ou get the shots you want, try different looks by moving the lights around and going through the process! Give the client the shot they are looking for, along with a few differnt looks that you like and that they might like as well!