[SML] Masking Projector Black

[smashwolf]

On 2/9/15 8:43 AM, Jerry Durand via Stagecraft wrote:
> On 02/09/2015 06:29 AM, Stephen Litterst via Stagecraft wrote:
>> Actually, many DLP projectors can do this.  My Digital Projections'
>> Titan unit has a menu option where I can bring in digital shutters
>> from four sides.  It accomplishes this by turning off the micromirrors
>> for the pixels that aren't desired.  Very effective.  I just wish they
>> gave me DMX control of this parameter so I can change it easily during
>> a show.
>>
>> Steve L.
>>
>>
> That would still essentially be video black, only at the projector end
> of the signal.  How is a DLP if you just put a super-black signal in
> (digital source, no analog sources)?
It depends on the quality of the preojector, and how much light is 
allowed to leak through.

For instance, a LCoS projector has 30,000:1 or better contrast ratio, so 
you can
literally calibrate black to absolute black, and black SHOULD be black.  
Some DLP
and some really high end LCD projectors can get close to black too. It's 
ore of a
calibration, and contrast ratio concern.  What people keep calling 
"Video black" is
actually just a term for "the grey for the light that errantly leaks 
through"  for instance
a 3-chip profesional DLP projector won't have a color wheel, but often a 
shutter for
between frames, and a LCoS projector will have a "advanced iris" shutter 
that will also
help block leaking light.  Just turn down the PJ brightness till there 
is no grey.
that sets your blacklevel to absolute black, and if you have a high 
contrast ratio, and
a wide color gamut, it'll look stunningly realistic.

The best part of this is that you can use one projector for multiple 
scenes with
different masks.  Most of these software packages usually DMX/ArtNet and 
Midi
capable, so you can assign it to lighting cues in your lighting console, 
etc.

-BRyan


-- 
Bryan Manternach, President, Smashwolf Productions & Studios
2883 Aiello Drive, Suite #3, San Jose, CA, 95111
408-363-8324, 408-209-3099 (mobile), smash at smashwolf.com