IMAG — Solid Foundations

28 08 2007

As promised, this is the first in a series of posts about the equipment needed for IMAG. I’ve decided that there is way too much information to cover in one post, so I’m going to do a series. This has the added benefit of giving me fodder for posts for a while ;-).

Like any good project, IMAG success starts with a good foundation. In the case of video acquisition, that foundation is the tripod. Now, you can spend more on a tripod  than you can on a house (actually it would be a pedestal at this price point), but most churches don’t need that level of product. However, a solid tripod is essential to getting decent images on the screen. The reason is simple. What looks like a tiny bobble or stick in a pan on 7″ monitor is a 6″ shake on a 16-foot wide screen. Creating big shaky images is a sure way to drive your audience nuts.

Let me point out that technically, a tripod is a three-legged stand. You don’t attach a camera to a tripod, you attach the camera to the head, which is bolted to the tripod.  The combination of a tripod (the legs) and the head (the pan and tilt mechanism) makes up a camera support system, commonly referred to as a tripod. From this point forward, when I say tripod, I mean the entire system.

So what kind of tripod do you need? That depends. Mainly it depends on what camera you are using, but it also depends on how long of a lens you are using as well. A “long” lens is one with greater telephoto capabilities. It zooms in farther an is often, incorrectly, measured in x as in 20x zoom—more on this in future posts. Again, let’s consider the logic. When you are zoomed way in (try this with a simple camcorder), very minor camera movements create huge shifts in the image. That’s why it’s darn near impossible to handhold a camera and get a steady image when you zoom in.

Back to tripods, you need a tripod that is rated to handle the weight of the camera you intend to put on it, plus any additional gear (studio viewfinders, focus and zoom controls, etc.). There are basically two types of cameras most churches will use: ENG type cameras and Camcorders. ENG style are cameras that can be shoulder mounted, they often have interchangeable backs (for a recorder, or a studio output), and will typically have a 1/2″ or 2/3″ imaging chip. Expect these cameras to run in the $15,000 and up range. Sony’s DCX series and D-30 are examples of ENG style. They will generally weigh in somewhere around 15-22 lbs. Thus your tripod needs to be rated for such a weight.

Camcorders range from the small Canon GL1 to the larger XL2 or H1. JVC, Panasonic and Sony all make “prosumer” camcorders, some of which can work for IMAG (with varying degrees of success). These are typically lighter (4-9 lbs) and demand less from the support system.

There are number of professional tripod manufacturers, and it behooves you to stick with a well-known brand. Companies like Vinten, Sachtler, Cartoni, Gitzo, Miller and Bogen have been around for a long time and make a wide range of tripods for all types of cameras and budgets (OK, maybe not all budgets…). Personally, I’m partial to Vinten because I’ve owned 2 of them and absolutely loved them. They are not inexpensive, however.

Ideally, you want to try out the tripod before you buy it. One good test I like to do is to set the pan drag control (if the tripod you’re considering doesn’t have tilt and pan drag controls, keep looking), near it’s highest setting—this will make it harder to pan the camera—and try a pan. When you stop, the camera should stop, not stop then go back a little from where you came from. On lesser tripods, they will “wind up” when you pan, and when you stop, they unwind giving you unwanted movement. You should also be able to balance the camera in such a way that with minimal tilt drag you and set the camera up to 45 degrees up or down without it moving on it’s own.

Also ideal is the ability to add 2 control arms on the tripod, so you can attach zoom and focus controls.  These little tools make is much easier for camera operators to get good shots and not have their arms falling off after a service. Varizoom makes some really cool zoom and focus controls for both Canon and Fuji lenses (used on the ENG style cameras) and for mini-DV camcorders—very cool!

As I said, adjustable tilt and pan drag are a must, and the controls for both should be easy to get to and operate in the dark. Such a tripod will not be inexpensive (a quick search on B&H shows them starting at about $800), but you’ll never regret spending the money. You’re better off with one camera on a good tripod than with three on cheap, unsteady ones. Trust me on this one. You can also find some really good deals sometimes on used equipment at TVProGear and Media Concepts.

Whatever you do, don’t go into a photo store (or worse, Wal-Mart) and buy a “video tripod” for $50-100. It may be barely passable for producing the occasional video, but it will not serve you well for IMAG. Your images will shake, you won’t be able to follow the speaker well and you will frustrate your volunteers who want to do a good job. And one more thing, still camera tripods are an absolute no-no for IMAG. They are designed to pan and tilt the still camera into position and lock there, not move smoothly from point A to point B. Do not waste your money. Just don’t.

Also, you don’t want to over-buy. Putting a 5 lb. camera on a head rated for 15-22 lbs. will not work well. The camera won’t have enough weight to effectively drive the pan and tilt mechanism, and you will not get smooth results. You want your camera’s weight to fall into the middle of the rated range of weights of the head. Again, trust me on this.

That’s a brief primer on tripods. There is a lot more to them than I’ve covered, but these are the basics. If you have other questions or want me to cover other options, leave a comment and I’ll see what I can do. I can go on for a while about video gear…



25 08 2007

I’ve been thinking about IMAG (Image Magnification) lately. We currently don’t do IMAG at Crosswinds, but I’ve done a ton of it during my career. As I read through the stack of church production type magazines I get each month, it appears more churches are moving into the IMAG arena. It makes sense, as worship rooms get larger (it seems that 2000+ room are becoming more common), there is a need to help those in the service see those on the platform. I’ve shot 200 some concerts as well as a few dozen other events, and here are few things I learned along the way.

The image on the screen should be bigger than in real life.
Seems obvious, right? But I can’t tell you how many times I’ve looked up at the screen and noticed that the image of the speaker is smaller than the speaker is in real life. The reason is simple: Directing for IMAG is different than directing for a tape or broadcast mix. Most directors (and camera ops) are uncomfortable staying as tight as they need to for effective IMAG. There is a tendency to pull out and show the overall scene. But think about this—if you’re seated 150′ from the platform, you already see the overall scene; what you want is a close up of the speaker so you can see their facial expressions.

The other challenge with staying as tight as we need to has to do with lenses. Long telephoto lenses are expensive, but they are necessary to getting a useful shot. My rule of thumb is this: A standard IMAG shot needs to be head to waist or closer. Ideally, you should go head and shoulders. If all you can get is a head to foot, you will not have an effective IMAG experience (unless you have mammoth screens).

Shot selection should make sense.
If you’re shooting a speaker who stands at a podium, you really don’t need to keep switching shots. I’ve sat through events shot with 5 cameras. And because there are 5 cameras there, the director felt the need to use all five, all the time. Again, consider the goal of IMAG—to show distant viewers a close up of the speaker. Cutting back and forth between cameras is distracting.

If the speaker walks the front of the platform, having three cameras, house left, center and right, will allow you the opportunity to cut to the camera that the speaker is facing. But if the speaker pauses at stage left, don’t switch to the house left (stage right) camera just to “change it up.”

If you are shooting a worship team or a band, the focus of the IMAG should be the worship leader or lead singer. Having multiple stationary cameras in the house allow you to highlight different instruments occasionally, and adding a handheld stage camera does even more. However, keep in mind that the people in the congregation didn’t come to see a close up of the bass guitar players fingers. That can be a very cool shot—for a second or two between phrases of a song. But please, don’t spend an entire verse there (unless you are using instruments as a background for lyrics, which is a whole different style).

When cutting a worship team, the cuts should follow the music. A soulful rendition of Amazing Grace doesn’t require (or benefit from) 30 cuts a minute. However, an upbeat tune like Dancing Generation could be enhanced by a few extra cuts here and there.

IMAG and broadcast mixes are different and need to be treated as such.
There is a temptation to combine the two functions, IMAG for the worship center and a “broadcast” mix for the in-house CCTV network for cry rooms, or hallway monitors. This is rarely optimal, however. As mentioned previously, IMAG needs to be close up shots. A broadcast mix needs a mix of closeups and establishing shots. For years I was stage camera op for a music festival in Ohio. We were supposed to be there for IMAG—our shots were projected onto huge 30′ screens for those at the back of the 10,000 person crowd. However, the director wanted to make live concert videos. They looked great when we watched the tapes at home, but the crowd was gypped. That wide sweeping shot of the crowd that moved up to the stage (using the 30′ crane) looked really cool, but the poor folks in the back already had that view. They wanted to see Toby Mac, not the people in the first 15 rows.

It sounds like I’m repeating myself, and I am. It’s important to think of IMAG as IMAG and broadcast as broadcast (regardless of how it’s “broadcast”).

Regardless of what you’re shooting, or how you’re mixing, you need the right equipment. Few things are more frustrating than trying to pull together a good video mix using equipment that was not designed for it. In the next post, I’ll give you some of my thoughts on the equipment you’ll need if you want to get into live video.


Improving Videos – Don’t Zoom Pt. 2

16 08 2007

It occurred to me recently that I never finished up this series on improving your video production. If you’re a new reader, you can pick up part 1 here, and then pick up part 2a and part 2b. All caught up? Good.

As I said in Part 1, incessant zooming is one of the hallmarks of amateur video. That’s not a good thing. It was even the subject of satire some years back when “Wayne’s World” popularized the “unnecessary zoom” on Saturday Night Live. I’m not sure what drives people to zoom in and out of a shot, back and forth, all the time during the shot. Perhaps it’s because Sony conveniently located the zoom control right under your thumb. Whatever. Once you hit record, don’t touch that zoom button.

Again, the goal is to produce really high quality video. Even if we don’t have great equipment, we can still utilize production techniques that are well accepted and produce excellent results. That’s where “zoom discipline” comes in.

Take a look at a well-shot film or TV show. You will not see very many zooms. You may see times when the camera gets closer to the subject (called a truck), but more than likely it is not a zoom. That’s because filmmakers use prime (non-zooming) lenses almost exclusively. They use prime lenses because they are sharper and produce a better image, but it also ensures there will be no “unnecessary zooms.” They also take great care in framing their shots in a aesthetically pleasing manner. Too many amateur videographers simply zoom in and out instead of taking the time to set up a great shot.

So here’s what I recommend: Whenever you press record, don’t touch the zoom control. After the shot is finished (and the recorder is paused), then you can zoom if you want to to get a different shot. Work on framing your shot in such a way that it works, looks good and draws the attention of your viewer where you want it to.

Another tip is to take a cue from filmmakers: Start the scene with a wide shot, then cut to a close up. Then you can cut to a medium shot. You can use the zoom to get all these shots from one vantage point, just stop the action while you zoom and cut (just a cut, not a dissolve, or effect) from one shot to the next.

Try this out on your next video project. Start to think of it in terms of a series of shots that will piece together. As I write this, it occurs to me that some visuals would be helpful. I’ll work on coming up with some sample pieces to illustrate my point. And perhaps from there, we’ll go onto some basic editing techniques. In the meantime, go make a video–just don’t zoom!


Audio for Video: Using High Pass Filters

23 07 2007

Note: This blog has moved to a new home. Church Tech Arts now has it’s own domain; you can view this post,
along with hundreds of others at the new location. Thanks for reading!

Let’s admit it: It happens a lot. Even when you pay careful attention to the audio you record for a video, and you used a good mic (you did use a good mic, right? if not read this…), you can still end up with a bunch of background rumble and noise in your recording. It happened just the other day to someone at the video production company I work for. They were shooting in a grocery store, capturing some interviews. They used a good shotgun mic, with good directivity to cut down on the ambient noise. However, there were those dreaded coolers all over the store, and if you listen carefully (mainly because our brain normally tunes them out), you’ll hear compressors running. Back in the studio, it sounds like a truck going by the entire interview.

Because it’s a complex noise source, trying to run a noise reduction program on it probably won’t work well (and even when the noise goes away, it is often replaced by unwanted digital artifacts of the FFT process used to perform the noise reduction—but that’s another post). However, we do have one tool in our utility belt that can help (actually two, I’ll get to the second, which should actually be the first, in a second): Enter the high pass filter.

A high pass filter is just what it sounds like—it lets high frequencies pass, while blocking low frequencies. Super-basic HPFs are a simple on and off switch with a pivot frequency (the frequency at which it “passes” signal) and slope (how quickly it drops off the signal below the “pass” frequency) set at the factory. Better HPFs that come with higher level editors like Premier Pro and Final Cut allow you to select the pivot frequency. Here is an example of an HPF with a pivot frequency of 120 Hz, and a slope of 12 dB per octave (that is, at the frequency 1 octave below the pivot frequency—60 Hz—the level will have been reduced by 12 dB).

High Pass Filter Example Graph

You can see how the frequencies above the pivot frequency pass by unaffected, while the ones below get rolled off pretty quickly.

This is when it actually gets useful. For the male voice, the fundamental frequency of the lowest notes one speaks is between 85-155 Hz. For a female, it’s a little higher, perhaps 165-225 Hz. This means that there is no real information that we need below 85 Hz for males and 165 Hz for females. And in reality, because of the way we hear and the way the voice is produced, there are plenty of harmonic frequencies that our brain will interpret clearly to make up for missing fundamentals.

So let’s say we have a compressor running in the background of a female interview. We can safely dial up a HPF with a pivot frequency of 165 and not loose any of her voice. We can take it up even higher to eliminate more of the noise, and the clarity will improve markedly. In fact, the voice will “sound” louder once the low frequency stuff is removed because we can hear it better.

So this is exactly what we did for grocery store woman. We dialed up an HPF with a pivot at around 150 Hz, and it totally transformed the audio. There was still some higher frequency noise, and it was obvious she was standing in the store and not a studio, but the clarity of here voice was improved substantially. If I have time later this week, perhaps I’ll grab a before and after sample and put it up here.

Earlier I mentioned we actually have 2 tools in our tool belt. The other one may be on the mic itself. Many professional shotgun mics (and some interview mics, and the occasional lapel mic) have a HPF built in. For example, my beloved Audio Technica 835B has a switchable roll off at 180 Hz at 12 dB per octave. That means at the lowest fundamental of a male voice the mic will be 12 dB down, which is generally not a big deal unless you’re interviewing James Earle Jones. Normally, I like to leave this switched on because it eliminates a lot of room rumble, AC noise and other nasties right at the source. It’s just a good idea. If you use this when you shoot, you will require less processing in the edit suite.

Of course, you’ll want to listen to it through some good headphones first to make sure you’re happy with the sound. You do have good headphones, right?