I'm having a hard time finding projection both glass. Does any one have a good source. I'm looking for the coated non reflective good stuff.
regards

search under port hole glass, a lot of threads discuss specific types.

Cineramax reccomended this glass here: http://www.us.schott.com/architecture/english/products/non_reflective_glass/amiran/index.html

Projection glass is a specific product. Not just any low reflection glass can be used. Projection glass is also color corrected. Ordimary glass causes a color shift.

I know about shot but they want you to go to dealer it not that easy most glass people are clueless. I was just wonder if a small shop / theater store custom did this. It seems that for home theater it's some what rare.
regards

I work at a mastering facility in Hollywood. I'll look up who we use.

Are you using this for a hush-box or have I totally misunderstood?

I got my hush-box glass from Edmonds Optical I think. Amazing stuff. People don't know there's glass there at all.

I went through this problem myself.

You need to consider the following questions:
1. Colour characterisitics of the glass
2. Absorbtion of the glass (like if you have a low lumen projector)
3. how many panes you use for soundproofing considerations and glass pane width
4. Size & construction of the porthole - purchased or DIY

I selected Amiran Water White 1/4" thick glass.
- Water White means low iron and no green colour shift
- Amiran is very low absorption glass manufacturer used in architectural projects and offer a variety of thicknesses
- 2 1/4" panes about 6" apart for soundproofing.
- porthole made to my specs out of MDF

You can find thinner low absorption glass, and thinner water white glass. Finding thick water white low aborption is hard. I purchased this from a glass manufacturer in New Jersey as I recall.

There are a couple of threads on this in the construction forum.

I know about shot but they want you to go to dealer it not that easy most glass people are clueless. I was just wonder if a small shop / theater store custom did this. It seems that for home theater it's some what rare.
regards

I have to happen to have 5 assorted pieces AMIRAN WATER WHITE AR COATED LOW ABSORPTION here in 12mm, only one pane required. This is the real **** . PM me if youd like.

http://cineramax.com/CES_2008/a7.jpg

the best is to have no glass at all.

as i report sice long time ALL filters optic isco lens and so on decrease the ansi cr.
by about good 30%.

that is also the case for the projection both glass.
a big tilt can decrease this lost but not very much may you have "only 25%" lost
in ansi.
it is much work and you have limitations but the best is without anything in between your screen and the pr. optic.
i did it this way and i will post a picture later.

the best is to have no glass at all.

as i report sice long time ALL filters optic isco lens and so on decrease the ansi cr.
by about good 30%.

that is also the case for the projection both glass.
a big tilt can decrease this lost but not very much may you have "only 25%" lost
in ansi.
it is much work and you have limitations but the best is without anything in between your screen and the pr. optic.
i did it this way and i will post a picture later.

I actually bought a piece of the Edmund AR coated glass for my port but, since the projector is pretty quite, and can't be heard except the back row of seats ,I followed this thinking to not take any more ANSI away from the set up.

It has worked out very well.

Art

Would defeat Superkontrast's rant against anamorphic optics, if that's the case.

Would defeat Superkontrast's rant against anamorphic optics, if that's the case.

In that install it really would be a must irrespective of that deleterious effects on ANSI.

Art

Eric, the Amiran Water White is what I'm looking for. I have a similar situation as you. I have an opening around 8" by 30" and the wall is 6" thick. I will need two pieces for noise reduction. My projector is a monster. tons of noise. I'm not worried about color shift or light loss. It's the noise that's killing me. Eric thank for your help I'll look into link.
CINERAMAX how large are your glass sheets.
Thanks for all the help. I'm new to the board and impressed with all the knowledge out there.
Regards

I think I was told with the ar coating you lose only 3% on each side of the glass. Art how big is your port hole aren't you a CRT guy?. I Know I have the loudest projector ever built. There's no way around it.
regards

all not coated glass surfaces loose at least 4% light.

so if you have a 8mm thick glass that have no color shift you loose at least 8 % light
when the surface is not on both sides coatet+ the light that the glass absorve.

mc coating reduce this 4% to about 0.1% or better normally coating (cheap one)
reduce the 4% to about 1%.

the ansi cr. drop is the same if you use glass that have coating or not.

W. mayer what options do I have?
Eric did you see that lose in cr to be that great?

I think I was told with the ar coating you lose only 3% on each side of the glass. Art how big is your port hole aren't you a CRT guy?. I Know I have the loudest projector ever built. There's no way around it.
regards

At the lens it's 7 1/2" square ,at the opening to the theater back wall it's 7 1/2" x 19"

http://www.artsonneborn.com//assets/images/db_images/db_Latest_16c1.jpg

W. mayer what options do I have?
Eric did you see that lose in cr to be that great?

use no glass and no cr.(i talk only about ANSI cr.!)
reduction.

use a glass get a very good one tilt it about 30 to 45° and take care that
it have mc coating on both side but expect at least 25% ansi cr. drop.

thats it.

there is no other option.

How is everone cooling there projection booth. I have a 3 ton unit for theater but no returns in booth. Is it best to install seperate AC unit in booth. I have large booth 18' by 10' and it settles at 105 F. when sealed of from theater.
The good news is the projector loves it. No lag on my screen, but the 1 hour warm up time not good.
regards

How is everone cooling there projection booth. I have a 3 ton unit for theater but no returns in booth. Is it best to install seperate AC unit in booth. I have large booth 18' by 10' and it settles at 105 F. when sealed of from theater.
The good news is the projector loves it. No lag on my screen, but the 1 hour warm up time not good.
regards

I'm using a ductless minisplit system.

Art

Eric, the Amiran Water White is what I'm looking for. I have a similar situation as you. I have an opening around 8" by 30" and the wall is 6" thick. I will need two pieces for noise reduction. My projector is a monster. tons of noise. I'm not worried about color shift or light loss. It's the noise that's killing me. Eric thank for your help I'll look into link.
CINERAMAX how large are your glass sheets.
Thanks for all the help. I'm new to the board and impressed with all the knowledge out there.
Regards

18 or 18.5 x 22 like shown, and 2 smaller 8 x 10 8x 8. This 12mm glass will kill a roaring engine.;)

Would defeat Superkontrast's rant against anamorphic optics, if that's the case.There was no huge loss of CR. If it did it was not more than 20 ansi. So I still have 840 ansi on a 2.40 screen

I Know I have the loudest projector ever built. There's no way around it.
regards

What proj do you have?

There was no huge loss of CR. If it did it was not more than 20 ansi. So I still have 840 ansi on a 2.40 screen

Peter,
I've yet to directly measure the center of each of the ANSI checkerboard squares with the Minolta. I will be interested to see the numbers on both this and on off when you have the opportunity. We got 6297:1 on /off at 25.2 fL on the Studiotek 130 X2 when measured on Friday.
Of course all of this is really moot. The proof is in the pudding and that is the great displayed picture.

Art

I meaured ansi loss of a Hoya CC filter at about 8%, Krasmuzik measured Ansi loss of a Hoya ND filter at about 5%. I would only presume ANSI loss from an engineered coated clear glass would be less than those figures, probably in line with what Cineramax states.

Peter,
I've yet to directly measure the center of each of the ANSI checkerboard squares with the Minolta. I will be interested to see the numbers on both this and on off when you have the opportunity. We got 6297:1 on /off at 25.2 fL on the Studiotek 130 X2 when measured on Friday.
Of course all of this is really moot. The proof is in the pudding and that is the great displayed picture.

Art

when you come down you are welcomed to bring Ken or some of his instrumentation.

Peter,
I've yet to directly measure the center of each of the ANSI checkerboard squares with the Minolta. I will be interested to see the numbers on both this and on off when you have the opportunity. We got 6297:1 on /off at 25.2 fL on the Studiotek 130 X2 when measured on Friday.
Art

Did Ken use a Minolta LS-100? Was this a measurement from the screen or projected to a surface closer to the lens?

Did Ken use a Minolta LS-100? Was this a measurement from the screen or projected to a surface closer to the lens?

LS100,from the screen at the approximate position of the primary seating ,several measurements to determine consistency.

Art

I meaured ansi loss of a Hoya CC filter at about 8%, Krasmuzik measured Ansi loss of a Hoya ND filter at about 5%. I would only presume ANSI loss from an engineered coated clear glass would be less than those figures, probably in line with what Cineramax states.

Yea ,I'd be interested in knowing if this is actually the case. At this point, in my room, I don't need glass but that could change. Peter's number is right around 2% although I'm betting that Wolfgang has measured to get his estimates.

Art

LS100,from the screen at the approximate position of the primary seating ,several measurements to determine consistency.

Art

A have a Minolta LS-100 and I am familiar with it's specs. Your black measurement was 0.004 fL. The measured CR is at least +/- 25% with black at this low level. This does not mean that it's not 6000:1, or even significantly higher, just that we don't know what it is.

A better way to do this is to project on a surface closer to the lens to bring the black measurement into the accurate range of the LS-100. The spec for measurements up to 1fL is +/- 2 digits of measured value or +/- 2%, whichever is larger. For measurements greater than 1fL, the spec is +/-2%.

A have a Minolta LS-100 and I am familiar with it's specs. Your black measurement was 0.004 fL. The measured CR is at least +/- 25% with black at this low level. This does not mean that it's not 6000:1, or even significantly higher, just that we don't know what it is.

A better way to do this is to project on a surface closer to the lens to bring the black measurement into the accurate range of the LS-100. The spec for measurements up to 1fL is +/- 2 digits of measured value or +/- 2%, whichever is larger. For measurements greater than 1fL, the spec is +/-2%.

Interesting,that you'd call me on this when Peter just off the top of his head said that he was losing no more than 20 points and says he has an ANSI of 840 with no measurements at all.:rolleyes:

Anyway thanks ,the same number was obtained with a another light meter( sorry didn't ask Chris Collins the model at the time) as well as with the technique you described with a piece of white paper two feet from the lens when I first got the projector. In those two the number was approximnately5900:1 (rounding since I didn't record it).

Would be good to revisit this. My guess though is it's pretty darn close to 6000:1 based on subjective comparisons to several projectors better and worse.

odyssey, are you using an anophormic lens? You are so right the super low level lighout reading are suspec to large error. I use a cs100 is it the same meter minus the color temp as the ls100? Has anyone seen a loss when using an anophormic lens. if so how much.
regards

odyssey, are you using an anophormic lens? You are so right the super low level lighout reading are suspec to large error. I use a cs100 is it the same meter minus the color temp as the ls100? Has anyone seen a loss when using an anophormic lens. if so how much.
regards

It's an acknowledged fact that an anamorphic lens will degrade ANSI significantly.

Art

odyssey, are you using an anophormic lens? You are so right the super low level lighout reading are suspec to large error. I use a cs100 is it the same meter minus the color temp as the ls100? Has anyone seen a loss when using an anophormic lens. if so how much.
regards

I am not using an anamorphic lens. Anything in the optical path will decrease ANSI CR and MTF. I am using glass (Schott water white Amiran) for sound isolation but have not measured the ANSI CR loss.

Art,

I didn't mean to pick on you about the CR measurement and you are usually more responsible about these things than others. Why did you post such a precise number when you could have just said that it was 30 times better?

Art, I use a fiber optic coupler that fits over the lenes then transfers all light to meter. It's real good at low levels because it gathers all the light. You can't do ANSI CR but you can dial in color balance at super low black levels.
Odssey, how do you keep your booth cool. Seperate AC unit? I know that your unit running a 2K lamp will put out some heat.
regards

Art, I use a fiber optic coupler that fits over the lenes then transfers all light to meter. It's real good at low levels because it gathers all the light. You can't do ANSI CR but you can dial in color balance at super low black levels.
Odssey, how do you keep your booth cool. Seperate AC unit? I know that your unit running a 2K lamp will put out some heat.
regards

ECS1, I now remember who you are. I have a fiber optic lens coupler for my Minolta LS-100 that came from our friend John S. I am using a 3kW lamp because I give up 75% of the light with aperture reductions to increase the CR. I have two split AC units to cool the non-vented projector room. The only problem is during July and August with outside temperatures above 95 degrees. The condensers are much less efficient at these levels and I am limited to about 3 hours of lamp on operation before the alarms trip. The projector has liquid cooling for critical parts like the DMDs, but I am very conservative with staying well below the maximum temperature spec.

the best is to have no glass at all.


Unless you want soundproofing.

Art,

I didn't mean to pick on you about the CR measurement and you are usually more responsible about these things than others. Why did you post such a precise number when you could have just said that it was 30 times better?

No problem,sorry.:o:D I did not realize ,actually, the inaccuracy of the device that low. The value was so simlar to the previous ones that I thought I could quote it.

Art

W. mayer what options do I have?
Eric did you see that lose in cr to be that great?

Well, its easy when you install it from the get-go with the glass in. But no, while I was concerned about the light loss and contrast reduction it was not a problem for me. And I have a Prismasonic lens too!

all not coated glass surfaces loose at least 4% light.

so if you have a 8mm thick glass that have no color shift you loose at least 8 % light
when the surface is not on both sides coatet+ the light that the glass absorve.

mc coating reduce this 4% to about 0.1% or better normally coating (cheap one)
reduce the 4% to about 1%.

the ansi cr. drop is the same if you use glass that have coating or not.


MC Coating means Multi Coating?

Unless you want soundproofing.

well i lost my right ear hearing since 7 months but
when i install the pr. i have both ears.

i design it that way that only the optic have a hole in the wall with
just about 3 to 4 mm arround to have some space for shift.

the hd 6k is not a quiet pr. as it is a prof. one with a 1200 w xenon lamp
but i can hear from the pr. almost nothing.

so it is possible to have both:)

MC Coating means Multi Coating?

yes:)

W. Mayer, I thinking I may be able to seal gap between lenes and port hole.
not sure if airflow would work.
regards

OK Guys I am about to pull the trigger on projecting my HT5000 from a port hole. The Port hole will require port hole glass due to sound issues as the media room is right next to the master bedroom. The port hole size will be 24" x 24" due to neccesary throw distance. Thanks to Peter I have selected the 12mm AMIRAN WATER WHITE AR COATED LOW ABSORPTION Glass, if its good enough for Helene it is good enough for Lon.

As far as setting the glass, it should be tilted toward the projector, is there a certain degree the glass should be tilted or is there a desired affect to look for when tilting the glass?

I am looking at a few different Pre fab Port hole frames to order...

6mm would be more than sufficient as long as it is glazed properly to be air tight. You are just trying to stop fan noise. Check with Kelmar Systems (Long Island) and Goldberg Brothers (Denver) for premade port window frames. Angle of glass should be such as to keep reflections (as there will be some even with AR coating) out of the lens.

Thanks Kevin:

As far as glass thickness I am trying to keep the noise from the media room out of the closet/master bedroom, not the fan noise out of media room.

Kelmer was on my short list as they are about 15 minutes from my house

OK Guys I am about to pull the trigger on projecting my HT5000 from a port hole. The Port hole will require port hole glass due to sound issues as the media room is right next to the master bedroom. The port hole size will be 24" x 24" due to neccesary throw distance. .

Lon,
Why such a tall port hole ?

Art

Art:

Throw distance problem, I need to have a throw of 20', the media room back wall is 17'10", so I need to set the projector 26" behind port hole opening, Thanks to CM and his fantastic Math skills we were able to determine the minimum opening would need to be 18.2" so I am leaving a margin of error to 24" opening.

I assume if the image area is 18.2" the opening would need to be at least 18.2"x 18.2".

Yeah better more than less (my case).

Has anyone tried leaving a hole just large enough for the lens with 602 fiberglass or similar material touching the outside of the lens to stop fan noise from coming into the theater?