Greenscreen soundstage reverb

[Doug Brandon]

thanks for the post SAL (if I may, it sounds a little more personal than SiliconAudioLabs)

I especially liked your .jpg of the foam rear shield.

Does anyone blanket the floor or is that some kind of no no? We just shot some green screen and fortunately did not see the floor. This allowed us to spread blankets all around (none hanging, floor only, secured very well because they can slide easily) which trapped LOTS of the verb, using an old senn 416. I understand the 416 is not the tightest for directionality (is that a word?), but nonetheless it's pointed at the floor from overhead. This seemed to work quite well.

Doug

[SiliconAudioLabs]

SAL is fine, Doug. :-D

Yep, we blanketed the floor and that helped quite a bit. The CMIT5 worked pretty well, but I'd bet my 416 would have worked, perhaps even a bit better, though the the time for trial and error quickly ran out for that.

One bizarre thing that happened - I had to do an ADR here in the studio and I used the exact same mics - CMIT and the Tram and the exact same recorder and yet the stuff recorded on the greenscreen was very, very silibant. Odd no filters had changed (slight roll-off on my SD 744 still set the same way) and none of the filters on the CMIT were engaged at either session.

Interesting what a room will do.

[David Waelder]

I've only done a few greenscreen shoots but they've often been memorable. Some years ago I did one of the Coors beer commercials that featured giants cavorting around the Rocky Mountains - a hoot. (And thanks again to Cabel Smith for passing it along to me.)

I've never had any problem about being permitted to place the mike in the shot - within reason. Everyone on these projects knows, or ought to, that removing extraneous items is easy. Often they'll put a piece of grip gear in the shot. I wouldn't want to push for the last millemeter; the whole idea is that the offending article is to be removed with a garbage matte rather than matted out with exquisite care.

For reverberant rooms I keep a piece of dense foam in my kit with a cut-out hole for my microphone. It serves a similar purpose to the Auralex foam kit. But mine isn't so fancy; I just cannibalized a mouse pad. One makes a small doughnut of the foam and slips it over the mike near the rear connector. This makes a physical block to sound waves coming from the back and increases (slightly) the directional qualities of the mike without any apparent liability. The way I deploy it, the width of the doughnut section is only an inch, maybe inch-and-a-quarter, to permit use in the shock mount, so the amount of rear audio restricted is limited. But, because is it deployed very near the inlet ports of the mike even an inch has a larger effect than you might think.

I picked up the foam trick from John Gilmore who has a similar practice. It's one of my favorite sort of gimmicks - the total cost is one mouse pad and ten minutes with scissors. If it works, great, if not, no harm done.

In terms of room control, it's very difficult to do anything effective in a stage 90 feet by 90 feet. I have long wondered how effective it might be to purchase a few of the portable bass traps, like the stand mounted LENRDs (http://www.auralex.com/bass_traps_sm-lenrd/bass_traps_sm-lenrd.asp), and move them around the perimeter of the shot for best effect. I would think you would need at least four of these to have any effect at all and that has always been more expensive than I was prepared to fool with. But a follow-up report from one of the "rich" sound mixers would be interesting. A single LENRD deployed in a bathroom might be both possible and worthwhile.

David Waelder

(working e-mail is my name + wae, my server is earthlink dot net)