Recommended External Microphones for Cameras

What is a directional microphone?

When we speak of a directional microphone, we are actually referring to a microphone with a supercardioid or hypercardioid (or sometimes simply cardioid) directional pattern to which an interference tube is added to narrow the pickup angle (more directionality).

But being rigorous, any microphone that is not omnidirectional would be a directional microphone.

The directional pattern of a microphone, also known as the polar pattern (because the sensitivity is represented in a polar diagram), gives us an idea of ​​how the microphone behaves with respect to the sound it picks up from different directions.

  • An omni-directional microphone picks up sound equally in any direction around it. It is a pressure microphone.
  • bidirectional microphone (also called a figure 8, figure eight ) picks up sound from the front and the sound from the back equally, and picks up nothing from the sides. It’s an open, pressure-gradient mic.
  • cardioid microphone picks up mostly sound from the front hemisphere. The typical angle of coverage is around 120-130 degrees. They isolate enough the sound that comes from the sides, especially from those 60º with respect to the frontal axis, and they isolate practically all the sound that comes from the rear hemisphere.
  • The supercardioid pattern has a narrower coverage angle in the front (about 110º) and isolates all sound from the sides and the rear hemisphere very well (except right on the axis at 180º, where it has some sensitivity)
  • The hypercardioid pattern is very similar to the supercardioid, but with a slightly narrower pickup angle (about 100º). In contrast, the sensitivity around the 180º axis is higher than in the supercardioid.

The basic directional patterns (cardioid, supercardioid, hypercardioid…) are achieved with microphones that combine the principles of pressure and pressure gradient . They are open microphones in which the sound reaches the membrane directly from the front, while from the back it arrives with a certain lag.

There are also microphones that combine two membranes or two capsules in opposition and their signals are electronically shifted to achieve different directional patterns.

When more directionality is needed, an interference tube is added to the capsule .

The interference tube has a series of holes or slots that collect sound from the sides in such a way that sound waves coming from the sides interfere with themselves and cancel out.

For example, shotgun (shotgun) type microphones usually have that elongated tube shape (interference tube)

These microphones use cardioid, supercardioid or hypercardioid capsules and with the interference tube they increase directivity (reduce the pick-up angle)

Since all these techniques are based on interference from sound waves (or signals) they are frequency dependent . Therefore all microphones have different directional patterns as a function of frequency.

For the higher frequencies (treble) they are much more directional than for the lower frequencies (bass).

In fact, the length of the interference tube is related to the ability to cancel or attenuate lower frequencies: the longer the tube, the lower the frequency for which effective attenuation of lateral sounds is achieved .

Shotgun microphones are usually classified as short, medium and long ( short / medium / long shotgun ).

  • Short barrel
    Its application would be similar to that of a cardioid microphone (super / hyper) but with a better behavior rejecting lateral sound, especially in mid and high frequencies. It is interesting to use them near the sound source.
  • Long
    barrel Used when the microphone needs to be placed away from the sound source. The pickup angle is very narrow, especially at high frequencies, and they reject the low frequencies of lateral sounds very well. They are more complicated to use because they have to be pointed exactly at the sound source, any movement of the microphone or the source can spoil the audio (the sound intensity that is outside the coverage angle is greatly attenuated, especially it is very sensitive in high frequencies)
  • Medium barrel
    A balance between directionality and ease of use.

The directional pattern of interference tube microphones (especially medium and long barrel) is often known as lobar (lobular) pattern, which is like a supercardioid tapered on the sides and depending on the model it can include lobes of certain sensitivity at different angles .

Why are they called shotgun, cannon, or boom?

The term shotgun (shotgun) or barrel refers to the shape of the interference tube. Some of these microphones can get very long and are shaped like a shotgun barrel.

The term boom comes from ‘ boom pole ‘, the typical pole with the directional microphone at one end that we see on film sets, etc.

Directional microphone vs shotgun / shotgun vs ‘on camera’ microphone

We are going to try to differentiate or clarify some terms or issues regarding directional microphones.

Is a directional mic the same as a shotgun / shotgun mic?

Do not.

A directional microphone is one that gives more preference or is more sensitive in certain directions. All microphones, except omni-directional microphones, are by definition directional.

But as a general rule it is understood that when we speak of directional microphones we refer to microphones that are more sensitive in the frontal direction (0º) with respect to the other directions.

All shotgun microphones usually include a capsule with a directional pattern : cardioid, supercardioid, hypercardioid … To which is added an interference tube .

A studio microphone, with a cardioid pattern, is a directional microphone, but it is not a shotgun microphone because it does not include an interference tube.

Furthermore, microphones with very short interference tubes have similar behavior to basic directional patterns in most of the sound frequency spectrum.

What is an ‘on camera’ microphone?

This is a very flexible definition and I don’t know what the Spanish translation would look like, but basically they are microphones that are designed and thought to be used on a camera, mounted on the flash shoe.

They are consumer range microphones , that is, they use 3.5mm jack connectors, consumer electronics signal levels (-10dBV) and quality standards according to these ranges and prices.

On the other side would be the professional range microphones, which use XLR connectors and are designed to work with stricter quality standards.

It does not mean that a consumer range microphone is bad or generates worse sound. Simply that they are intended to work in a consumer electronics environment .

On camera microphones vs shotgun microphones

Most on-camera microphones follow a cardioid or supercardioid directional pattern.

They are all short-barreled and the effect of this short interference tube is very small in practice. Only for high frequencies is a perceptible directivity achieved with respect to the base pattern (supercardioid for example)

This type of microphone is intended for general use, covering many types of situations.

As they do not have a very closed directional pattern, it is preferable to use them close to the sound source.

The shotgun microphones for professional use are more specialized.

The range of use will depend on the length of the interference tube, the base pattern of the capsule, its sensitivity and its behavior in terms of electronic noise (among other characteristics).

They tend to have a more closed lobar (lobular) pattern at the front, much more directive, but they also tend to have larger lobes of sensitivity at the rear and at certain angles on the sides. They can be more complex to use in certain reverb situations.

They are not intended to be mounted on the camera. They are usually used with a pole and depending on the situation and directionality, they will need an operator who points exactly to the sound source.

And the recording with this type of microphones would be done through a sound interface or a digital recorder (with XLR inputs)

Since the microphone can be located several meters from the sound recorder, balanced XLR cables provide protection against interference and induced electronic noise.

When to use directional microphones (shotgun / shotgun)?

Remember that the distance between the sound source and the microphone greatly influences the sound quality.

It’s always important to place the microphone as close to the source as possible:

  • To isolate any unwanted ambient sounds as much as possible.
  • The intensity of sound decreases with the square of the distance. As we move the microphone away, we will need to amplify the signal more with the risk of generating more electronic noise and also when amplifying we will capture more ambient sound.

However, it is not always possible to place the microphone very close. For example, if we are going to record a video sequence in which we do not want any microphone to be seen.

Or for practical reasons it is sometimes more comfortable to work with the microphone at some distance from the sound source (instead of using a lavalier microphone, a handheld microphone or a studio microphone for example).

Directional microphones are used for such situations.

The main objective of a directional microphone is to isolate or reduce the greatest amount of ambient sound with respect to the sound we are interested in recording.

Keep in mind that when we use a directional microphone it is due to a compromise between the limitations imposed by the recording and the sound quality we want to achieve.

It is still important that the microphone is as close to the sound source as possible.

Limitations of Directional Shotgun Microphones

More than limitations, they would be characteristics that must be taken into account when we use this type of microphones.

Most of these characteristics are intrinsic to the technology that these microphones use, they do not have to do with the quality of manufacture, range or price:

  • They are usually more sensitive to the wind . It is important to use them with some windshield / dead cat. Some models include the option of activating a high pass filter that eliminates the lower frequencies associated with wind noise.
  • Microphones that use interference tube often pick up low-frequency sounds that are outside the theoretical coverage angle. In some environments this can lead to unwanted effects.
  • The more directional a microphone is, the more sensitive it tends to be on the 180º axis (sounds coming from the back)
  • Also, the more directional the microphone, the more care must be taken when aiming at the sound source . For example, if it is a person speaking who is moving around the scene, it may happen that they leave the maximum coverage area, causing quite perceptible changes in the recording levels.
  • The interference tube works very well in open environments, since the sound that comes through is clean. In closed environments , depending on its acoustics, ambient sound can bounce and reach the microphone with a certain intensity. As the interference tube is based on phase difference sound cancellation, bounced sounds (which arrive out of phase because they have traveled different distances) can cause effects such as comb filtering (comb effect or comb filter) that attenuates or eliminates certain frequencies by altering the audio from the original of the sound source.
  • In closed environments we can also find that the low frequencies that bounce off walls and ceilings can enter the microphone from the sides causing unwanted effects.

Here we are generalizing: each microphone, each model, is designed to work in certain situations.

In addition to these physical limitations, it must be taken into account that as we separate ourselves from the sound source, the microphone will generate weaker electrical signals.

We will have to amplify the signal much more and there will be more risk of deteriorating the signal to noise ratio.

In this part, sensitivity of the capsule and quality of the associated electronics , there can be substantial differences between microphones of different ranges.

Can a directional microphone be used as a studio microphone?

Yes.

It could be used as a desktop microphone, connected to the computer through some sound interface (or directly to the microphone input of the computer, although keep in mind that the preamps of the sound cards integrated into the motherboard of a computer do not they are usually very good)

It can also be used mounted on the camera if we want a very simple configuration, without cables or complications.

It can be used with some type of support or pole in such a way that it is closer to the person who is speaking, but out of the frame .

Take into account in any case the limitations that we have commented:

  • If the microphone is very directional it will be very sensitive to the movement of the person speaking : if they move outside the coverage angle, if they turn their head in another direction, etc.
  • If the room has poor acoustics, bounced sounds (reverb) can affect this type of microphones more (compared to a studio microphone )

Directional microphones recommended for cameras

Criteria for choosing these models:

  • Models designed for use with cameras (SLR / EVIL) or even with mobile
  • Good value for money
  • Easy to use

Rode VideoMicro

It is a very small and light microphone, perfect for both cameras and to connect to a mobile phone.

For mobile phones there is a specific Rode model: the Rode VideoMic Me , which is basically the same microphone, but with a rigid TRRS jack connector that is plugged directly into the mobile (without a cable).

Although the VideoMic Me could be adapted to a camera (buying for example a shock mount or there are also designs to print a shock mount for the Me in a 3D printer) I think it is less versatile than the Rode VideoMicro, which already includes the Rycote shock mount to attach to the flash shoe.

If you are going to use it on mobile phones, it is convenient to buy a rig (frame), a support or cage in which we can place the mobile, add accessories such as the microphone, a led panel … and it gives us the possibility of mounting it on a tripod. There are also rigs for different camera models that allow us to connect several accessories at the same time.

Keep in mind that the Rode VideoMicro has a 3.5mm TRS jack connector, which is usually the one that cameras include. To use on mobile you will need a TRS to TRRS adapter.

It is an electret capsule condenser microphone that does not require external power. The internal electronics are powered through the camera or mobile jack connector ( plug-in power ).

The directional pattern of the microphone is basically cardioid (about 6dB of attenuation for lateral sound and over 12dB of attenuation for the rear hemisphere).

The frequency response is quite flat and in general it is a microphone that offers good sound quality .

Positive points of the Rode VideoMicro:

  • Good sound quality (depending on the recording conditions)
  • There is a good quality price relation
  • The pack includes the microphone, TRS male-male jack cable, Rycote shock mount and windshield (dead cat)
  • It does not need external power. We do not have to be aware of batteries, and we do not have to remember to turn it on every time we are going to use it

Less positive points:

  • It’s basically a cardioid pattern mic, not too directional. If we use it at a very great distance from the sound source it will pick up much of the ambient sound.
  • It does not have any type of active filter (eg high pass filter to reduce wind noise) or configuration options.
  • As it does not carry an active preamplifier, it can be more vulnerable to external electromagnetic interference

Rode VideoMic NTG

It is one of the most complete shotgun microphones for cameras.

The most outstanding feature is that it includes its own sound interface with USB output:

  • We can use it on camera, connecting it directly with the 3.5 jack to the camera’s microphone input or we can use a sound recorder
  • Or we can connect it directly to a computer without the need for an external sound interface: we can record outdoors from a laptop or we can use it as a studio microphone for recording or streaming.

What controls / functions this microphone includes:

  • Gain control dial
  • Two high-pass filter modes (75 and 150Hz)
  • Boost mode for high frequency (+ 6dB at 4KHz)
  • -20dB PAD (attenuator)
  • Possibility of recording with security channel (backup at -20dB)
  • Clipping / saturation indicator

The polar pattern is supercardioid. It has a fairly flat frequency response, with the option of boost in the 4K area to increase the clarity of the sound.

It has the auto ON / OFF function, which automatically detects when the camera is turned on and off. This is great because you don’t have to be aware of whether the mic is on or off.

It uses a rechargeable battery with autonomy of about 30 hours. The battery is recharged through the USB connector.

You have the option of recording with a security channel . In this mode, one of the channels (right) records with the gain options configured at that moment and in the other channel (left) a copy of the sound is saved but with -20dB of attenuation to protect the quality in case of peaks of very loud audio.

Positive points of the Rode VideoMic NTG:

  • Very good sound quality for this range (still consumer electronics)
  • Very versatile – can be used as an outdoor camera microphone and as a studio microphone
  • Ease and flexibility in handling
  • Includes anti-vibration system (shock mount)
  • Good value for money for the functions it offers
  • When working with the USB connection, the 3.5mm output can be used to monitor the sound with headphones

Less positive points:

  • Some packs do not include the 3.5 jack cable to connect to the camera (in that case it would have to be purchased separately)
  • Remember that directional microphones are more sensitive to the wind (you must always use a windbreaker and preferably dead cat)
  • Remember that these microphones are very sensitive to reverb. If you record indoors you must be very careful with the acoustics of the room.

Rode VideoMic Pro

Within this Rode line of directional microphones designed specifically for cameras, the VideoMic Pro is perhaps the most balanced in terms of performance and design, and overall it has a good value for money.

It is one of the best selling microphones.

The VideoMic Pro includes a half-inch capacitor capsule and is powered by a 9V battery (about 60-70 hours of autonomy).

The directional pattern is approximately supercardioid. It’s not quite as directional as a specialized shotgun mic, but it rejects lateral sounds quite well.

It includes a PAD, an attenuator, of -10dB, which is used for example when we use the microphone very close to the sound source or if we are recording situations with very loud sounds (car races, motorcycles …)

It also includes a + 20dB amplification option, which comes in handy especially when we use it connected directly to the camera.

The idea is that the camera’s preamp is usually quite mediocre and it is always interesting to have it in the lowest part of gain. The microphone’s + 20dB preamp is generally much better. The microphone will provide us with a preamplified signal, more immune to possible external interference, with a better signal-to-noise ratio and that will allow the camera preamplifier to work in a more linear area.

If you connect the microphone to a recorder, you will probably want to disable the + 20dB option. But in any case you will have to test which combination is the one that works best with your camera and / or your recorder.

The Rode VideoMic Pro also includes a selector to activate a high pass filter, with a cutoff frequency of around 80Hz. This filter is useful for example in windy situations, since it will eliminate the lower frequencies without affecting the sound quality of the voice too much.

The microphone has an antivibration system (shock mount). The newer versions usually come with a small Rycote Lyre damping system (the older ones have their own Rode mount).

Positive points of the Rode VideoMic Pro:

  • Good sound quality for its range and price
  • Possibility of using the internal pre-amplifier (+ 20dB) to improve the sound with respect to the pre-amplifier of the camera
  • Possibility of using attenuator (-10dB) in situations with very loud sounds or if we record very close to the sound source
  • High pass filter mode at 80Hz
  • Good value for money
  • Good ratio between performance and size

Less positive points:

  • You need a battery (you can also find rechargeable 9V batteries)
  • We always have to remember to turn it on before we start recording (one of the most typical and frequent errors with microphones that are externally powered). In addition, it does not have any led or indicator on the front. And we have to remember to turn it off when we finish the session or for the next session we will find that the battery is exhausted.
  • The directional pattern would correspond to a supercardioid. It is a microphone designed to work at relatively close distances to the sound source. In general, it covers most typical situations well: vlogging, studio use, etc.
  • Remember that directional microphones are more sensitive to wind (you should always use a windbreaker and preferably dead cat) and to reverb if you record indoors. Poor acoustics in the room or studio can greatly affect the audio quality.

Rode VideoMic Pro + (Plus)

We could say that it is an updated version of the VideoMic Pro, with some interesting improvements. Although the performance in general and the sound quality are very similar.

One of the most outstanding features is that the microphone automatically detects when the camera is active , it is not necessary to turn the microphone on and off. This is one of the best inventions in the world, because recording with the microphone off is very, very frustrating.

It uses a rechargeable battery and can run on 2 AA batteries. The battery is recharged inside the microphone itself through a USB connector, so we can feed it with an external powerbank. And in case of emergency, if we carry spare AA batteries we can use it with batteries.

It includes the same attenuation (-10dB) and gain (+ 20dB) system as the VideoMic Pro.

Instead of a high pass filter, the VideoMic Pro Plus has two modes, with cutoff frequencies at 75Hz and 150Hz, that you can use in windy situations or environments with annoying sounds in the bass area. Remember that for low frequencies the microphones are much less directional.

It also includes a mode that reinforces the mid frequencies, about + 6dB around 4KHz, which can be useful when recording voice in environments with a lot of ambient noise or simply to give more clarity to the voice.

Another remarkable feature is that it includes the option to record with a security channel. In this mode, one of the channels (right) records with the gain options set at that moment and in the other channel (left) a copy of the sound is saved but with -20dB of attenuation.

This security channel gives us much more leeway. If, for example, during recording there are sounds louder than expected and the main channel saturates (clipping) distorting the sound, we can use the second channel to use that part without saturating.

Positive points of the Rode VideoMic Pro + (Plus):

  • Good sound quality for its range and price
  • Possibility of using the internal pre-amplifier (+ 20dB) to improve the sound with respect to the pre-amplifier of the camera
  • Possibility of using attenuator (-10dB) in situations with very loud sounds or if we record very close to the sound source
  • Two high-pass filter modes (75 and 150Hz)
  • Boost mode for high frequency (+ 6dB at 4KHz)
  • Possibility of recording with security channel (-20dB)
  • Good value for money for the functions it offers

Less positive points:

  • The directional pattern would correspond to a supercardioid. It is a microphone designed to work at relatively close distances to the sound source. In general, it covers most typical situations well: vlogging, studio use, etc.
  • Much bulkier than the VideoMic Pro
  • The output cable is connected to the jack connector on the back and can sometimes be annoying, especially if we try to use the camera’s viewfinder.
  • Remember that directional microphones are more sensitive to wind (you should always use a windbreaker and preferably dead cat) and to reverb if you record indoors. Poor acoustics in the room or studio can greatly affect the audio quality.

Shure VP83 / VP83F LensHopper

If we take the Rode VideoMic Pro as a reference, the Shure VP83 would be located in a slightly higher range in terms of build quality, with the metal body.

For example, shielding against electromagnetic interference is better on the Shure. Rode microphones tend to be a bit more exposed, perhaps because they use more plastic in their construction.

The VP83F version includes its own integrated digital recorder . If you are going to use a single microphone, it may be a good option, because the entire recording system is integrated and optimized (there are no impedance matching problems, bad connections, cables in between, etc.)

In terms of sound quality the differences with respect to the VideoMic Pro are small and would fall within the subjective part and preferences of each one.

The frequency response of the Rode VideoMic Pro is a bit flatter in the high frequencies, while the Shure has a small boost around 5 KHz (similar to the high frequency boost mode of the VideoMic Pro +)

The Shure VP83 is a condenser microphone that includes an electret capsule and the necessary internal electronics. It needs to be powered by an AA battery. The autonomy would be about 75-100 hours depending on the quality of the battery and the parameters of use.

The polar pattern is basically supercardioid, with an attenuation of about -10dB at 90º and 180º, taking the 1 KHz frequency as a reference.

The Shure VP83 includes a -10dB attenuation mode and a + 20dB preamp mode.

As we have already mentioned, the PAD (attenuator) is used when we record very loud sounds (cars, motorcycles, places with very loud sound or if we speak very close to the microphone …) and the + 20dB mode is used especially if the microphone is connected directly to the camera, so the camera preamps work at the lowest possible gain level.

It also includes a low-pass filter with a cut-off frequency around 150Hz, which can be used for example in windy situations or environments with a lot of reverb to attenuate low frequencies.

Positive points of the Shure VP83 LensHopper:

  • Good sound quality for its range and price
  • Good shielding against electromagnetic interference
  • Possibility of using the internal pre-amplifier (+ 20dB) to improve the sound with respect to the pre-amplifier of the camera
  • Possibility of using attenuator (-10dB) in situations with very loud sounds or if we record very close to the sound source
  • High pass filter mode at 150Hz
  • Good value for money

Less positive points:

  • Needs one AA battery / battery ( VP83F version uses 2 AA batteries )
  • We always have to remember to turn it on before we start recording. It does not have a led or indicator on the front. And we have to remember to turn it off when we finish the session.
  • The frequency response includes a small boost in the 5KHz area that you may like more or less depending on your preferences.
  • The directional pattern would correspond to a supercardioid. It is a microphone designed to work at relatively close distances to the sound source. In general, it covers most typical situations well: vlogging, studio use, etc.
  • Remember that directional microphones are more sensitive to wind (you should always use a windbreaker and preferably dead cat) and to reverb if you record indoors. Poor acoustics in the room or studio can greatly affect the audio quality.