Before we start configuring camera systems let’s touch briefly on the advantage of using professional batteries. Imagine you’re on a shoot using the AF-100, a nanoFlash and a field monitor hooked up to a rod support system rig and a follow focus. The camcorder, recorder and monitor all require power — and before you know it so will the follow focus. Sure, they have their own batteries, but keep in mind, all these batteries are different from one another, each with their own shapes, voltages, capacities, chargers, charge times, etc. Chances are you’ll also want a couple of spares for each device, just to be safe. Before you know it, you’ve created a full time job: keeping track of all the batteries, swapping them out, monitoring their charge, charging them, etc. However, with the proper cables and know-how, you can connect all of these devices to one power source — a source that in most instances has a higher capacity than the individual batteries.

Configuring Your Set-up

The first thing you need to do is to pick a battery mounting option. If you are planning on using a camcorder like the Panasonic AF-100 or the Sony F3 we carry a shoulder mount/ rod-support rig made by Zacuto that has a gold plate attached to it.  For everything else, we recommend our Universal AB Mount: a gold plate attached to a Manfrotto superclamp, allowing you the ability to attach your professional gold mount batteries pretty much anywhere. As an added bonus, if you plan on using a shoulder mount for handheld work the 5.5-pound Hytron 100 makes an excellent functional counterweight for shoulder mount work. In fact, the Zacuto rig was designed with this in mind, and the Universal mount can be easily configured to a shoulder mount for this function.

The Universal AB Mount and its many uses.

The next thing you need to do is to figure out which connectors go with the items you want. Gold plates output via D-tap connector so ultimately you will need a cable that goes from D-tap to the power input of your device. Keep in mind a gold plate has one D-tap output and some of the other adapters include one additional D-tap output, so depending on the number of devices being connected, you may require a D-tap Multitap. What follows is a list of camcorders/ accessories and the cables you’ll need to connect them to the gold plate.

Camcorders/ Cameras

• Panasonic AF-100 →   AF-100 D-tap Adapter (has one additional D-tap port)
• Sony PMW-F3L →   XLR 4-pin to D-tap
• 5DmkII, 7D, 60D →   Canon DSLR to D-tap (has one additional D-tap port)

Accessories

• nanoFlash →   Hirose to D-tap
• AJA Kia Pro Mini →   XLR 4-pin to D-tap
• Marshal HD/SDI field monitor, Marshall HDMI field monitor →   XLR 4-pin to D-tap

Lighting

• ARRI Locaster → XLR 4-pin to D-tap
• Litepanels 1×1 Flood and Spot →  Litepanels 1×1 Battery Adapter
• Litepanels Ringlite → XLR 4-pin to D-tap

How Many Batteries?

The final step is figuring out how many batteries you’ll need to get through a day of shooting. The actual amount of energy a battery contains is a bit confusing because some describe energy in terms of watt-hours, while others tell you the operating voltage and milli-amp hours (mAh). Watt-hours is easiest to use for this sort of calculation, so we want to convert from the second notation into the first. One watt equals one volt times one amp, so you can convert from mAh to Wh by multiplying by voltage. For example, a 14.4 volt, 2500 mAh battery contains 36 watt-hours of stored energy.

Note also that you can add or divide the time component as needed. If a battery can supply 10 watts for 1 hour, its capacity equals 10 watt-hours. That same 10 watt-hour battery could also supply 5 watts for 2 hours, or 20 watts for 0.5 hours. There are other considerations making this not exactly accurate, but textbook math like this works well enough for estimating.

Once you know what your battery can supply, you need to know how much you’re consuming. For that reason, we’ve listed estimates below of the power needed to run some common gear.

Currently we carry Anton Bauer Hytron 50 and Hytron 100 batteries which, conveniently enough, have a capacity of 50 and 100 watt-hours respectively.

Actual power available in the battery will vary in the field, especially due to differences in operating temperature. Cold batteries might deliver half of their normal output. Nevertheless, by adding up the power requirements of the gear you plan to use and dividing by capacity of the battery, it’s pretty easy to approximate how much energy you will require. As always, choosing to err on the high side will give you a more conservative estimate, whereas reality may settle more in the middle.

As a concrete example: you have a Sony PMW-F3 (22W), an AJA Kia Pro Mini (5W), and a 7″ Field Monitor (25W), drawing 52 watts in total. If you plug it into a Hytron 100 battery, you have 100 watt-hours divided by 52 watts, yielding an estimate of 1.92 hours of runtime.

The AF-100 (and most other camcorders in its class) can be powered by the Hytron 100 for approximately 6 hours. If you add a nanoFlash and a monitor, this drops to approximately 2 to 3 hours of battery life. That said, you can reduce your main battery load by using external equipment with its own power supply. For example, the nanoFlash comes with its own battery that has about 2.5 hours of battery life, and most of our monitors have the adapter to mount an NP-F970 battery directly, which will power the monitor for about 2 hours as well.

A typical setup including a professional camcorder, monitor, audio adapter with a phantom power shotgun mic will need about 60 watts of power, so a pair of Hyton 100 batteries should provide up to 3 hours of power time without recharging.

The recharging time for the Hytron 50 and 100 are 3 and 6 hours respectively. We currently carry 2 chargers for Anton Bauer batteries: the Twin which can charge 2 batteries at once, and the Tandem which can charge a battery and power your devices at the same time from one AC input.

Once you have an idea of what you will be working with and the conditions you are working under, getting into the ball park of how many batteries you’ll need shouldn’t be too hard. Keep in mind that it’s always better to have too much power than to have too little, and you’ll still have all the supplied batteries as back-up should the need arise.

Happy shooting!

For ND filter basics check out the ND filter section of this article.

Effect of a 1-stop ND filter

Alternatives to Using ND Filters

When shooting video outdoors or in brightly lit places, using an ND filter is often a necessity in order to get proper exposure. Video-makers have access to the same in-camera options for controlling exposure as photographers. However, it is important to understand the affects these options will have on footage – it can be quite different than the effects they have on photography.

These options include:
1. Reducing ISO (Gain)
2. Increasing shutter Speed
3. Reducing Aperture (Iris)

Reducing ISO

ISO on DSLRs and digital video cameras is a mock representation of “film speed”. Sometimes referred to as gain control, these settings find most of their use in low light situations. It is important to note that different ISO settings will effect your image quality. In very basic terms, the lower your ISO setting, the sharper and less noisy your image will be (there is some argument as to what the ideal ISO setting is but most agree that it fits within the range of 200 and 400).

To some subtle, nuance-minded cinematographers, the noise and softness associated with certain ISOs may be a desirable element of the overall picture quality. Ultimately the decision on whether you want to make ISO a creative decision (“I really feel like the graininess of the image reflects inner psyche of the main character”) or a utilitarian one (“We have to drop down to 100 ISO because I didn’t bring along enough ND filters and we are over-exposed!”) depends on personal preference or circumstance.

For the most part ISO setting is primarily a consideration for low-light situations (situations where you normally wouldn’t use ND filtration anyway, i.e.: at night), on bright sunny days even the lowest ISO setting won’t keep your exposure from blowing out, therefore only two real options: aperture and shutter speed are left to control exposure.

Increasing Shutter Speed

There are compelling reasons you shouldn’t use shutter speed control as a means to regulate exposure, but it is an option. Adjustment of the camera’s shutter speed has a major impact on the fluidity and movement within the frame (not to mention movement of the frame). Simply stated, lower shutter speeds let more light in and movement within the frame appears smoother; higher shutter speeds allow less light into the camera and result in jerkier or more frenetic action (i.e.: the battle sequences in Saving Private Ryan). Shifting from a more standard shutter speed (such as 1/30 or 1/60) to a higher shutter speed can have a profound affect on the overall look and feel of your footage and it is important to take these affects into consideration before making any shutter speed adjustments.

As with ISO, the decision of where to set your shutter speed comes down to creative or utilitarian decision (DOP: “We have to up the shutter speed because we’re already set at 100 ISO, I don’t have enough ND filters and we’re over exposed! But don’t worry, it’ll give it that cool Saving Private Ryan battle scene look.” Director: “But we’re shooting a romantic-comedy.” DOP: “Yes, but I feel like this overall look really reflects the inner psyche of the main characters”).

Reducing Aperture

It’s no secret; people shooting video with DSLRs want to achieve shallow depth of field. Some people refer to this as good depth of field because shallow depth of field “looks better”. Others refer to a wide focal plane as good depth of field. People who wish to be understood don’t ever use the phrase good depth of field.

It stands to reason (and our experience) that as a means to achieve a shallow depth of field, DSLR shooters aim to shoot with the aperture as wide open as possible, which of course exposes the sensor to more light. (Director: “Couldn’t you just close down the iris on the lens and then we could keep our ISO and shutter speed the same throughout?” DOP: “Yeah, but then we wouldn’t get good depth of field.”). Reducing the aperture, for most shots, changes the entire look and emphasis of the scene.

Neutral Density Filters to the Rescue

Ultimately if you wish to achieve a good exposure and avoid using the extreme ends of shutter speed and aperture control; ND filtration is a necessity. At the very least, keeping an ND filter on-set arms you with more options and offers you less compromise when it comes time to shoot.

ND Filtration vs. In Camera Exposure Control for DSLR Video