| Author |
Message |
Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
|
| Posted: Sun Jan 06, 2008 4:56 pm Post subject: New problem that all HT projection systems suffer from! |
|
|
Sometimes I have to laugh at the absurdity that the high end forum over at avs brings...
http://www.avsforum.com/avs-vb/showthread.php?t=969520
Still, I wonder if on a really small scale, things like this COULD affect an HT. Dunno if anyone reads Cineramax's posts, but he's really an over the top guy. It sounds like he knows what he's doing, I've got no problems with him, but some of his claims are way over the top.
Is there any chance of this claim being true so that you see a visible difference in image? Cliff, can you light a fire in front of your stack and tell me if the image is affected? 
|
|
| Back to top |
|
 |
ronholm
Joined: 26 Jan 2007
Posts: 12111
|
| Posted: Sun Jan 06, 2008 5:01 pm Post subject: |
|
|
HAHAHAHA.....
Some folks are to smart for der own gud...
This is just more proof of dat...
So what exactly is the speed of light? And just how fast would air have to move, and/or change in temperature to refract light?
This dude must have one hell of a furnace.
_________________
Play stupid games, win stupid prizes
|
|
| Back to top |
|
|
Zebu Fellenz
Joined: 21 Dec 2006
Posts: 2567
|
| Posted: Sun Jan 06, 2008 5:12 pm Post subject: |
|
|
| Quote: | | Cliff, can you light a fire in front of your stack and tell me if the image is affected? |
Curt,
Of course this would affect the image, Having a fire burning in front of the stack would ruin the black level. Now if Cliff was running a Digital he wouldn't have that problem  
Erik
|
|
| Back to top |
|
|
jkruger
Joined: 24 Oct 2007
Posts: 2435
Location: Carlsbad, CA
|
| Posted: Sun Jan 06, 2008 5:27 pm Post subject: |
|
|
 WOW!!! MISSION CRITICAL!!!  
|
|
| Back to top |
|
|
stefuel
Joined: 07 Mar 2006
Posts: 3353
Location: Green Harbor MA USA
|
| Posted: Sun Jan 06, 2008 6:33 pm Post subject: |
|
|
I could not read that BS without putting my .02 worth. But while we're on this rediculous subject, what exactly does any of that "mission critical" stuff have to do with home theater? I think it's time for someone to piss in a cup
_________________
Chip
A Barco is only a AmPro with training wheels
Card carrying member of the AVS chain gang.
|
|
| Back to top |
|
|
garyfritz
Joined: 08 Apr 2006
Posts: 12088
Location: Fort Collins, CO
|
| Posted: Sun Jan 06, 2008 7:50 pm Post subject: |
|
|
Thermals absolutely can affect an image. His "shuttle" pic is proof of that.
But in an HT? NFW. It takes a looong distance before it becomes evident with e.g. hot air rising off the pavement. Have you ever noticed a car's headlights "twinkling" when it's in the distance? But as the car comes closer and closer, the twinkling disappears. Same thing happens with larger images. If you drove closer to the shuttle in that picture, the shimmer would go away.
Another factor is the size of the light source. Stars twinkle but planets don't -- not because of the stars' distance, but because of their pinprick size. With a tiny point light source you are much more vulnerable to image shimmer. Planets don't twinkle because of their larger disc.
With the short distances and large images in an HT, I cannot believe this is an issue, short of a bonfire or other huge heat source right under the lenses.
|
|
| Back to top |
|
|
StuntDummy
Joined: 08 Aug 2007
Posts: 59
Location: San Francisco, CA
|
| Posted: Sun Jan 06, 2008 8:10 pm Post subject: |
|
|
|
Wow, lol. Maybe Cineramax just needs to wrap his brain around some sudoku or something, that is if he can see the pages through the thermal distortion.
|
|
| Back to top |
|
|
Sonynut
Joined: 08 Aug 2006
Posts: 367
Location: Bradford,PA
|
| Posted: Sun Jan 06, 2008 8:14 pm Post subject: |
|
|
As stated, the only issue would be a HOT heat source between projector and screen.. then you are just asking for it.
_________________
1272 Stack coming soon:)
|
|
| Back to top |
|
|
AnalogRocks
Forum Moderator
Joined: 08 Mar 2006
Posts: 26706
Location: Toronto, Ontario, Canada
TV/Projector: Sony 1252Q, AMPRO 4000G
|
| Posted: Sun Jan 06, 2008 8:19 pm Post subject: |
|
|
I guess if you set your tea kettle, popcorn machine and your propane burner you use for doing the corn roast in the fall between you and the screen then you may have an issue. I wonder if he see's mirages?
_________________
Tech support for nothing
CRT.
HD done right!
|
|
| Back to top |
|
|
perisoft
Joined: 29 Aug 2007
Posts: 2920
Location: Ithaca, NY
|
| Posted: Sun Jan 06, 2008 8:21 pm Post subject: |
|
|
The only suitable response to this is to get a couple of bricks, dip them in plastic, put a nice badge on them, and sell them for $9,700 a pop to place to each side of your screen as Thermal Mitigation Devices. Once one guy has them, clearly no self-respecting videophile can live with himself without a pair (or, if you're SERIOUS, you run a quad) of TMDs.
_________________
|
|
| Back to top |
|
|
overclkr
Joined: 08 Mar 2006
Posts: 4227
|
| Posted: Sun Jan 06, 2008 8:47 pm Post subject: Re: New problem that all HT projection systems suffer from! |
|
|
| Curt Palme wrote: |
Is there any chance of this claim being true so that you see a visible difference in image? Cliff, can you light a fire in front of your stack and tell me if the image is affected? |
Yeah big dog I agree, he is a little bit out there.........
Cliffy
|
|
| Back to top |
|
|
chrisc1122
Joined: 10 Dec 2007
Posts: 12
|
| Posted: Sun Jan 06, 2008 8:56 pm Post subject: |
|
|
That is getting just a bit ridiculous. Whats next, Esoteric Air that will need to be pumped into the building to prevent distortions. Hey, maybe someone hear can come up with a modded air conditioner. I hear it improves the picture quality :)
Damn, I just can' remember what I did with that deed to the Brooklyn Bridge.
|
|
| Back to top |
|
|
Joust
Joined: 05 May 2006
Posts: 2429
Location: Almonte, Ontario, Canada
TV/Projector: Marquee 8501LC
|
| Posted: Sun Jan 06, 2008 9:28 pm Post subject: |
|
|
OH THATS WHAT THE PROBLEM IS....
I was wondering why when i project over a 100 yards of extremely hot pavement that I see those ripples and mirages in my screen.
|
|
| Back to top |
|
|
Sonynut
Joined: 08 Aug 2006
Posts: 367
Location: Bradford,PA
|
| Posted: Sun Jan 06, 2008 9:30 pm Post subject: |
|
|
Too bad we don't have those mile-long-throw lenses for our CRT's so we could worry about this too... LOL
_________________
1272 Stack coming soon:)
|
|
| Back to top |
|
|
Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
|
| Posted: Sun Jan 06, 2008 9:37 pm Post subject: |
|
|
BTW, did you know that thermals affect sound too over long distances. I attended a Syn aud Con seminar about 10 years ago where they talked about Meyer making bass cannons that 'threw' bass 100s of feet. Depending on the temperature of the stadium depended on where the bass ended up.
And no, I'm not BSing, I'll google later and see if I can find anything on that.
|
|
| Back to top |
|
|
garyfritz
Joined: 08 Apr 2006
Posts: 12088
Location: Fort Collins, CO
|
| Posted: Sun Jan 06, 2008 9:42 pm Post subject: |
|
|
|
I don't doubt it at all. Sound travels in air. If the air is moving, it affects the sound. I imagine thermals cause bending and refraction of the sound waves. With enough distance, it could have a noticeable effect.
|
|
| Back to top |
|
|
AnalogRocks
Forum Moderator
Joined: 08 Mar 2006
Posts: 26706
Location: Toronto, Ontario, Canada
TV/Projector: Sony 1252Q, AMPRO 4000G
|
| Posted: Sun Jan 06, 2008 9:51 pm Post subject: |
|
|
| Curt Palme wrote: | BTW, did you know that thermals affect sound too over long distances. I attended a Syn aud Con seminar about 10 years ago where they talked about Meyer making bass cannons that 'threw' bass 100s of feet. Depending on the temperature of the stadium depended on where the bass ended up.
And no, I'm not BSing, I'll google later and see if I can find anything on that. |
I've experienced this at a bon fire with the boom box on one side and us on the other. BY coincidence that was about 10 years ago too. It sounds pretty cool.
_________________
Tech support for nothing
CRT.
HD done right!
|
|
| Back to top |
|
|
ronholm
Joined: 26 Jan 2007
Posts: 12111
|
| Posted: Sun Jan 06, 2008 10:24 pm Post subject: |
|
|
| Curt Palme wrote: | BTW, did you know that thermals affect sound too over long distances. I attended a Syn aud Con seminar about 10 years ago where they talked about Meyer making bass cannons that 'threw' bass 100s of feet. Depending on the temperature of the stadium depended on where the bass ended up.
And no, I'm not BSing, I'll google later and see if I can find anything on that. |
I'll bet those guys that build "sound weapons" would know a thing or two about that.
Directed Acoustic Weapons
In the past, acoustic non lethal weapons were primarily used as "flash bang" weapons. When blasted over a crowd or in a room, they created a loud noise and bright flash incapacitated people exposed to the effect for a few seconds. Flash bang charges are used on forced entry and counter-terror operations, when hostages are involved. As they indiscriminately hit every human exposed to the effect, operation of "flash-bang" requires precise timing and procedures to maximize effect on hostiles and eliminate potential damage to friendly forces.
Currently, acoustics are far more advanced than mere noise. Following the impressive technology advancement in solid state electronics, advanced acoustic systems are becoming operational. In 2004 American soldiers in Iraq were equipped with a Long Range Acoustic Device (LRAD) used for land based and naval applications. LARD works like a highly directional, high power megaphone, able to blast sounds (such as crowd-dispersal instructions in Arabic) in a narrow beam and with great clarity at a deafening 150 decibels (50 times the human threshold of pain). LRAD can also create deafening noises which can incapacitate people within 300 meters by "firing" short bursts of intense acoustic energy.
A different acoustic weapon is the vehicle mounted Acoustic Blaster, developed by PRIMEX Physics International. This weapon can be used for area denial, and against selected groups in crowds, mobs and rioters or in a hostile situation. The weapon can be operated by a single person. So far the system was developed as a prototype consisting of an array of four combustion detonation driven devices fired simultaneously or independently. The detonation creates an acoustic pressure of up to 165dB at a distance of 15 meters. The resulting acoustic pressure waveform can be optimized for acoustic-physiological coupling to targets for antipersonnel applications. The US Air Force Research Laboratory (ARL) is also working on a Sequential Arc Discharge Acoustic Generator (SADAG) which produces high-intensity impulsive sound waves generated by electrical means.
A different acoustic weapon is the high power acoustic phased array of 36 horns which can focus the acoustic output at the target. The high power noise created within the target can incapacitate humans from a standoff range. The system can be mounted on a tactical vehicle, and radiate a narrow, high power steerable acoustic beam, disorientating humans. Both horizontal and vertical beams can be formed simultaneously to create a point effect within buildings.
A different application is the shockwave weapon, employing the Vortex Ring Gun system. Generating high power shockwave propagating at supersonic speed, Vortex ring Guns can generate high pressures which inflict considerable damage to a target, or carry a payload of kinetic or chemical agents over a distance beyond 20 meters.
_________________
Play stupid games, win stupid prizes
|
|
| Back to top |
|
|
stefuel
Joined: 07 Mar 2006
Posts: 3353
Location: Green Harbor MA USA
|
| Posted: Sun Jan 06, 2008 10:29 pm Post subject: |
|
|
Well I'm happy to be the first one in that thread to even touch on the fact that it would effect sound before vision.
What a marooooooooon
_________________
Chip
A Barco is only a AmPro with training wheels
Card carrying member of the AVS chain gang.
|
|
| Back to top |
|
|
d50q
Joined: 22 Nov 2007
Posts: 118
Location: ma usa
|
| Posted: Mon Jan 07, 2008 2:06 am Post subject: |
|
|
|
that Esoteric Air could smell like the movie theater.....phew
|
|
| Back to top |
|
|
|
|
