[John Sharaf]

Broadcast News (and Weather) that uses keys and virtual sets most all use switchers with built in keyers. They use multiple layers of these to put in news crawls, chyrons and other graphics on top of the foreground talent and background maps. I’m sure there are other software solutions, but the modern switchers provide a tactile user interface that has great familiarity in broadcast control rooms.

JS

[John Sharaf]

Chris,

Although I am not familiar with that particular CCU, here is some information I was able to find via Google search:

Interfacing to Sony CCUs

We found three issues to deal with when interfacing Sony CCUs to Clearcom-type systems. Please review the circuit description and schematic diagram for the Clearcom-type system.

* Balanced vs. Unbalanced.
The Sony CCUs we have dealt with (CCU-M3 and CCU-M5) use balanced audio and the Clearcom analog system uses unbalanced. This was solved very simply with a small 1:1 audio transformer. We used a small (< 1-inch cube) surplus transformer we had, the kind that are used in dial-up modems. They don't have very good frequency response at the low end or the high end, but then that is actually desirable in an intercom. Limiting the bandwidth to voice frequencies reduces incidence of interference, noise, and distortion. transformers like this are commonly available from places like All Electronics, Digikey and Mouser. * Signaling The Clearcom system uses the same wire for both the intercom audio, and for signaling. The audio is AC coupled, and the signal is a DC component on top of it. We decided that we didn't need signaling out to the camera operators since: a) the camera operators are supposed to have their headsets on all the time; and b) the tally circuits built into the cameras and CCUs provide a "call" function. We just used a capacitor to AC-couple the Clearcom audio line to the transformer to keep DC out of the transformer. * Audio Levels This was the biggest problem. The Clearcom system runs at a significantly lower level than the Sony intercom. When we first devised the interface (just the capacitor and the transformer), it worked, but the receive level at the cameras was too low for practical use in noisy environments (like musical programs). And the microphones on the cameras were way too loud compared to the Clearcom intercom stations. We use these cameras and CCUs almost exclusively in a production unit where all the control-room personnel (director, AD, TD, shader, tape operator, etc.) are using Clearcom-clone intercom stations. Because of this, we decided to modify the cameras to boost the audio level to the earphones in the camera op's headset, and to attenuate the mic signal. We made a very small (postage stamp size) circuit board with an op-amp booster and a volume control to knock down the mic level. This has worked out quite well for us, but it might not be practical for everyone, and especially not for rental equipment(!) Actually, it wouldn't be hard to package the earphone boost and microphone attenuator into a very small external package which could be used with any camera, but it is not the elegant, no-modification solution we would have preferred. So what it comes down to is an interface unit which connects between the Clearcom bus and the CCU bus (simply the transformer and capacitor); and another unit on each camera which boosts the earphone level and attenuates the mic level. * CCU Interface Circuit * Camera Amplifier/Attenuator Circuit Feedback to: rcrowley dot com

[John Sharaf]

Hi Eric,

Just for starters, if all you need is one person coverage, an 8×8′ screen is plenty big. I’d recommend proper Kino Flo units to light the screen rather than hardware store units. In fact, for considerations of electric use and heat, I’d suggest you use Kinos for the three point lighting as well, so:

1 @ 2’Fourbank
2 @ 2′ Twobanks
2 @ 4’Twobanks

Start the greenscreen party!

JS

[John Sharaf]

My bad, early morning grogginess. The point is that users of these types of products have a shared experience and are often called upon to move fluidly between different cameras referred to as XDCAM.

JS

[John Sharaf]

Don’t forget PMW-700, PMW-F800 and related decks PMW-HD1500, PMW-HD1600 and PMW-U1 Reader/Writer.

JS

[John Sharaf]

Sony has chosen to categorize the EX3 as well as the PDW800, F900R, F650, F23/F35 and the new SRW9000 all as “Cine Alta” cameras. This is because they all shoot 24p in their basic sales offering, and are intended for “Digital Cinema” use. I don’t see any problem in lumping them all together in the Cine Alta Forum, even though issues common to EX3 users most likely will not be of much interest to F35 users. But in these days of many diverse camera platforms it is of interest (to me anyway) to keep up with the issues raised by all these cameras in production use.

There are other forums, notably the CML, which has many hard and fast rules segregating discussions based on imager size, recording format, etc, but I see the Cow’s role here as being a lot more democratic in opening up to a broader user base that I feel benefits many more people.

JMHO,

JS

[John Sharaf]

That’s better. I was spelling his name wrong! He’s a great guy. I used to work with him at ABC Net News in LA and learned a lot from him.

JS

[John Sharaf]

You are absolutely correct in saying that you want a shadow from the key light. What you want to be careful of is two (or even three shadows) from the fill and/or backlight, this makes the scene look artificially lit, not natural. As always with greenscreen I also advise some consideration as to what you will have in the background. The more you match the direction and quality of the light depicted there on the foreground, the more convincing the effect of the final composite.

When you say however, “I also think that in the worst case, we can always shine 1 extra light from a top side down onto the subject to help eliminate shadows”, that is exactly what you don’t want to so. If anything, wash out the shadow with a floor light, out of the shot that does not leak onto the foreground subject. Remember most keying deices and programs have “cleanup” which will let you erase the sahhow completely if you wish. This is why sometimes it’s best to make a trial composite on set, so you really know what it’s going to look like. You can often save a reshoot this way!

JS

[John Sharaf]

Hi Ed,

Low tech method is use slate, like in the old school film days.

JS

[John Sharaf]

Nels,

I’d be careful about characterizing lack of experience as ignorance, especially as it concerns motion picture lighting; for to be successful in this field means you are always open to learning new tools and techniques and all that is really required is an inquisitive mind, which you certainly have!

JS