Noise Canceling Headphones

During a recent plane flight, I got to experience the joy of Noise Cancelling Headphones. They work using level matched phase inversion of sound which cancels out any exterior noises. They feature two small microphones [one on the side of each ear piece] and measure the external sound levels. By playing the sound back into the head set at the same level [now phase inverted], the noise is cancelled out. Just brilliant!

Other brands like Sennheiser also now produce noise cancelling head phones as well.

Mark

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The Shape Of Things To Come

If history is to repeat itself, then this TV might just be a clue to the future of home entertainment. Back in the early 1990's, Phillips released a 1.78:1 TV in a time when all other TVs were 1.33:1. At the time there was no programing to support the new wider screens, but in a short time, HDTV and DVD became standards that allowed the user to benefit from the wider displays.

The LCD TV shown above is the new Phillips display known as Cinema 21:9. A Standard HDTV uses a pixel array of 1920 x 1080. This new type of ultra wide display uses a pixel array of 2560 x 1080. What this means is that new programing in the form of packaged media will be released to allow a true 1:1 pixel mapping. So what does this mean for 16:9 displays?

In keeping with the idea of "backward compatibility", new source formats will have a 16:9 feature as well as the new 21:9 option. The 16:9 option would reformat the material back to the same standards we have now for our 16:9 displays where a film in Scope would once again be presented as a letter boxed image. However, at full resolution, the image would contain 2560 x 1080 Vs the current 1920 x 810 letter boxed image where the remaining 270 lines make up the black bars [top and bottom] we have now. The ultimate system would allow us to have 1080 vertical resolution for all programs.

So what about projectors and CIH? Well this might just be exactly what we have been waiting for. If the new 21:9 player is set to 21:9, the image should be a matrix of 1920 x 1080 with the geometry appearing to be horizontally squeezed. This means that we do not have to "scale" the image for CIH as it will be done at the source level. Whilst we won't get to use the full 2560 pixels width, we will have 1:1 pixel mapping for our 1920 x 1080 panels. This means that our images will be true anamorphic and anamorphic lenses will be needed if full rez of the new formats are to be used on 16:9 projectors.

The future is looking promisingly w i d e ...

Mark

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MK3 Mounting Solutions

Due to popular demand, the CAVX Projector Station will once again be available to all that purchase an Aussiemorphic Lens MK3. The Station will be laser cut and feature holes needed for the mounting of many popular 1080 projectors, cable management and allow for precise threaded adjustment to ensure that your projector is 100% level.

Projector Station : $499.00AUD

Mark

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DVDO Edge - Affordable Scaling for CIH

With CIH progressively becoming more mainstream, the need to control the Aspect Ratio from one central video processing device that not only enhances the picture, but offers flexibility needed for CIH has become required. The DVDO Edge is not only functional, but affordable.

With enough video inputs to process all of your video needs, the DVDO Edge represents a centre hub of video control.

For more information, visit http://www.anchorbaytech.com/dvdo_edge/

Mark

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CIH Explained - Easy Math

The purpose of this page is to simplify issues such as calculating the Throw Ratio [TR] needed for using an anamorphic lens with a projector. Rather than redoing the CIH Explained page, I am adding this one, focusing on the math needed for working out proportions in your room.

SCREEN SIZE

The size of the screen is best found by dividing the room's length by 4.5. I've used 4.5 as it a 'round' number, but the actual number you use can be anything between 3.68 and 5.18 and where '4.5' is somewhere in the middle of that, but closer to the long end of the range. Dividing the room's length by the chosen number gives you an ideal screen height for that room that allows you to work out both Seating Distances and Throw Ratio.

EG 1: Room length of 6000mm / 4.5 = Screen height of 1333mm

If you want a larger screen than the math allows, then the best way to test this is to set the projector up at the back of the room and measure the height of the light at the minimum zoom [smallest image size]. This is handy for also checking the image height when an AT screen is to be used as these usually require the screen to be built out from the wall.

ASPECT RATIO

The aspect ratio is simply the width in relation to the height to denote the shape of the screen. 35mm film CinemaScope has an Aspect Ratio of 2.39:1 meaning the projected image is 2.39 times wide as it is high. As it turns out, our Home Theatre equivalent is 2.37:1. This is because TV's evolution to wide screen has been based on 1.33x steps where SD is 1.33, HD is 1.78:1 [1.33 x 1.33] and Scope is 1.78 x 1.33. The actual math requires the decimal point to be taken to at least 7 places .

1.3333333 x 1.3333333 = 1.7777777 and

1.7777777 x 1.3333333 = 2.3703702.

EG 2: Screen Height of 1333mm x Aspect Ratio of 2.37 = Scope Screen Width of 3159mm

SEATING DISTANCES

With 1080 projectors, you can sit as close as 2x the image height but should not sit further back than 4x. These are based on SMPTE recommendations and SMPTE's preferred distance is 3x the image height and the THX 36 degree rule is 3.68x the image height.

EG 3:
Screen Height of 1333mm x 2.00 = 2666mm [closest seating distance]
Screen Height of 1333mm x 3.00 = 3999mm [SMPTE Preferred]
Screen Height of 1333mm x 3.68 = 4905mm [THX furthest seating distance]

Note that in the 6000mm deep room, that you are off the back wall, so allowing for Back Surround speakers to be placed behind the seating location[s].

THROW RATIOS

The diagram shows that the beam angles become wider when using a Horizontal Expansion Anamorphic Lens. To ensure the best results, the TR really needs to be as long as possible. I am recommending a TR of not less than 2.0 [or greater] be used with the Aussiemorphic Lens MK3 for most HT projectors. There will be some cases that require the projector to be mounted way further back than the calculated TR of 2.0:1 gives.

The easiest way to find the Throw Ratio and or Projector Mounting distance is to use the following math.

Scope Screen Width x 0.75 x TR [in this case 2.2 = distance of projectors lens from screen.

EG 4: Scope Screen Width of 3159mm x 0.75 x 2.2 = 5212mm. Again, this page is an example and your individual projector may need to be mounted further back. If the projector can not be mounted back far enough, the screen height may need to be reduced.

Mark

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Upgrades - Will They Ever End?

I recently upgraded my AVR to the Pioneer VSX1018AH. This AVR is only THX Select 2, but it does feature the latest format decoders [DTS HD MA and DDTrHD] and given that processing seems to be the fastes evolving part of Home Theatre these days, I have decided to take a different path from the norm. The way I see it, our Home Theatres can be broken into 2 major groups [just like like real cinemas] - the A chain [Source Components and Processing] and the B chain [Amplifiers, Speakers and Room Acoustics]. Generally speaking, we are less likely to upgrade the B chain, but with BD came new audio formats that I decided that I needed to own.

When you purchase an expensive AVR, you are paying for the quality of the amplification as well as DACs and processing, and given that it is very possible that the current line up of processing could reach an end of life sooner than later, why not just upgrade the parts that needs upgrading?

I used to have separates [pre/pro and power amps] and I would someday like to go back to that arrangement, as dedicated power amplifiers do make speakers sound nicer [warmer] than the amps built in to an AVR. A few units like the one pictured below would be sweet!

So the way I see it, this AVR will serve as an AVR until I get my power amps, then serve as a good pre/pro. Should there be new formats or a reason to upgrade, I simply replace the AVR. The reason I suggest an AVR is that dedicated pre-pros are very hard to move as whoever buys it has to have separates to use it.

Mark

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A Dark Night on Blu-ray Disc

December 2008 saw the release of A Dark Night on Blu-ray Disc. This film was presented theatrically in two different film formats - 35mm film using conventional CinemaScope and IMAX using the higher rez 70mm film format. Whilst in the conventional cinema, the film was presented in CinemaScope 2.40:1, parts of the film had been originally shot for IMAX using the larger film format and was presented this way at speciality events capable of 70mm projection.

Bringing it home to Video has created some confusion as the Blu-ray Disc release of this film features the IMAX footage presented at full HDTV's 1.78:1 whilst the rest of the film is presented in a letterboxed format. It should be noted that real IMAX is actually closer to 1.44:1, so some material has been cropped to fit this in the 1.78:1 frame.

If you are like me and into CIH, then you can simply watch this film the way you most probably saw it in your local cinema - in CinemaScope - as the "Scaling" process used in CIH will remove the portions of IMAX footage outside the 2.40:1 frame along with the normal letterboxing black bars. However, if you wanted to create a system that will allow you to view this [and any future films in this format] you may need to combine both CIH and a really large 16:9 screen [with top and bottom masking] together.

Given that the BD version of the is film is trying to recreate the IMAX experience, you really want the IMAX portions of the film to be much larger than the rest of the film and given that Scope image height is based on seating distances, or vise versa, you want the Scope portions of this film to be maxed out for your seating distance so that when you see the IMAX parts, they are much taller. The letterboxing on the title means that approx 810 lines are used for the active picture and the remaining 270 are used to create the black bars. When the IMAX footage is seen, it will use the full 1080 lines. The idea of still using an Anamorphic Lens is to allow you to still watch all of your other "Scope" films the way they were meant to be seen, as well as keeping your other 16:9 program at the same height within the borders of the top and bottom masking.

The Screen:
What is required is a 16:9 screen the same width as the "Scope" screen you would normally use and this screen would have to feature removable top and bottom masking to allow you to create the Scope screen in the centre portion. This masking would remain in place for all programs except those shot in IMAX and maybe HD music videos like rock concerts. Your seating distances should still be worked out as if the Scope screen is the largest screen or minimum of 2x the height of the Scope screen not the 16:9 screen.

The Anamorphic Lens:
I use a Horizontal Expansion lens to allow me to create a Constant Image Height system should I chose to remove the lens from the light path of the projector. However I don't remove the lens and therefore if I had sufficient throw, I could use a Vertical Compression lens and achieve the same result. A VC lens would allow all 1080 lines to be vertically compressed into the same space as the letterboxed image allowing you to use the full panel of the projector. And this might just be the answer to this new problem. The new Aussiemorphic Lens [MK3] will be reversible to allow both HE or VC operation making it perfect for this kind of application providing that you throw is long enough.

Viewing the film.
This is probably the only case where you would be correct in watching this film in a letterboxed format. With the top and bottom masking removed, you would really experience the IMAX footage in proportion to the rest of the film based on your seating distance [SMPTE minimum is 2x the Scope mage height]. for the Scope portions making the IMAX events eye candy at 1080 vs the 810 for the Scope portions. When watching other films, you would move the VC lens back in place to reduce the image height and close the top and bottom masking and use the system like a conventional CIH system. You might even want to add side masking for 1.78 and 1.33 program.

I don't think this will become a mainstream method of film making, so I am sticking with a 2.37:1 screen for now.

Mark

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The Importance Of The Centre Speaker

The purpose of the centre channel speaker is to reproduce ALL the program in the centre of the sound stage. In today’s multi channel world, we use 3 speakers to reproduce the front sound stage – Left, Centre and Right. Therefore the quality of the centre speaker becomes very important to how well it will blend in with the Left and Right speakers. Sure “stereo” has traditionally being considered a 2 channel medium, but the very first stereo recordings [Bell Labs in the 1930’s] actually used 3 speakers to create the sound stage. The only reason we have 2 channels for “stereo” today is that 2 channels is all that could fit into the groove of a vinyl record. Unfortunately, all following formats for “stereo” music reproduction would only use 2 channels until the release of “multi-channel” recordings on formats like the SACD and DVD-A.

Multi-channel music goes beyond the front stage to include surrounds and even an LFE channel. The exact amount of content sent to each channel varies from recording to recording and can be perceived as spacious and enveloping when mixed correctly. Film sound has always [post 1977] been mixed as multi-channel, and the number of channels has now expanded to 7.1 discrete channels [Blu-ray Disc]. However, because the centre speaker can be responsible for up to 90% of a motion picture's soundtrack, the quality of the speaker reproducing this channel needs to be as good as the L and R speakers.

My LCR Array

I use identical LCR speakers for two reasons –

1. Sounds do not change timbre as they pan across the stage.

2. I do not hear an audio quality change when switching from 2ch to MC program.

Whilst centre speakers can be bought individually, it is difficult to find a store that will spit a pair of "main" speakers so that you can have three identical LCR speakers. The solution is to therefore work out a budget for speakers and find the best centre speaker [that you both like and can afford] and buy three. As I am also a fan of bass management, I also recommend including a subwoofer in that system.

Mark

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SAMSUNG BD-P1500

I have finally added a Blu-ray Disc player [Samsung BD-P1500] to my EQ rack. At last I can play the [limited] collection of Blu-ray titles from MY HD COLLECTION...

SAMSUNG BD1500

I recently had the Firm Ware in the BenQ W5000 updated to allow true 1080P/24 playback. After setting up the player to output 1080P/24, all I can say is WOW, how good does that look?

UPDATE: Not only does the Samsung BD-P1500 play Blu-ray discs allowing me to watch films at 1080P/24, but it also beautifully up-scales SD DVD as well outputting the up-scaled video at 1080P/50 or 1080/60. This player loads quite fast for a HD unit as well, with most titles averaging about 25 second load times.

A few pleasant surprises I have got with this player are:
1. It provides Horizontal Squeeze to native 4 x 3 discs meaning that they display with correct geometry on either the 16:9 or wide mode, or with the anamorphic lens in place and using the 4 x 3 mode. Not that I watch that much 4 x 3 content, but nice to know anyway.

2. Subtitle Relocation for subtitles overlayed as a bitmap like this example of from the film STAR WARS. This player has certainly given "A NEW HOPE" to those into CIH.

3. It passes PLUGE too...

Mark

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D6500K And Why It Is So Important

When you purchased your new TV [plasma, LCD etc], was it on display among many different sets? Did you choose it because it produced the brightest image in the room amongst the sets on display?
Did you really think it was the best of the bunch?

If you answered yes to any of these questions, then sorry, but your most likely not getting the quality picture you have just paid for.

FACT: All video is mastered at a specific colour temperature known as D6500K. Unless your set is running at this colour temp, your not seeing the images as they were meant to be seen. YOU WILL NEED TO GET IT CALIBRATED.

CIE Diagram

In order to make a set unique and stand out, set manufactures increase the colour temperature. This may seem to make the set appear brighter, but it also makes the images look more blue. To understand what this means, you need to understand that a video display is colour temperature related similar to the filament of a light bulb. If we apply a steadily increasing voltage to a light globe, first it glows red, then orange, yellow and eventually white. If we keep increasing the voltage, the metal will actually glow blue just before it pops. So in essence, blue is the hottest colour. Our video displays work exactly the same.

If we take a look at the above images, you will clearly see a colour shift between the two. The second image is the original [after the camera was white balanced first], and the one above is too hot [made this way with photo edit where all I have done is to increase the colour temp]. As the colour temp is shifted up, the image becomes more blue. The Blue image is similar to what a video display [TV ] set to about or above 7500K would look like. Any hotter [more blue] and the manufacture would have to add a red push to make skin [in this case the fruit] tones look believable.

I have marked the D6500K point on the CIE diagram with a red dot. Typically, most new TVs out of the box are going to measure about 9300K which you can find by following the arc to the left. If you choose to leave your display set this colour temperature, then 2 things could happen -

1. All of your images will look blue [the bananas don't look ripe in the top image].
2. You could actually shorten the life of your new display.

The only way to see video the way it was intended is to have your video display calibrated to D6500K.

There's no grey quite like 6500K :)

Mark

PLEASE INQUIRE ABOUT CALIBRATION HERE

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CEDIA 2008

CEDIA [2008] is on again and on Friday the 1st of August, I headed down to the Gold Coast Convention Centre to check out the latest Big Boy's Toys on offer. Naturally, I was there to see what was on offer for CIH, but there was also many other new and exciting products on offer and many interesting things to see from speakers...

... to this 3 screen D-Box flight simuator...

...to the latest products like this 1080 3 chip DLP CIH solution from RUNCO, so there was something for everyone...

Being that I am right into CIH, I thought that I had better document some of the things I saw:

Schnieder made a huge presesnce this year with their entire range on display including their flagship, a 200mm monster seen behind the more commonly known 4" Cine-Digitar.

This massive lens was also being used in a very impressive HD3D system projected onto a curved Stewart Microperf screen. This is simply the best 3D I have seen to date, and can only hope this is the future of home entertainment...

Apart from some awesome anamorphic CIH, there was also Panasonic's "blended" systems from featuring these massive DLPs...

...producing a 2.66:1 image projected onto a 4m wide curved surface...

Or multi Plasma arrays which can configured to run either vertically [shown below] or horizontally.

There was actually more to see than I could possibly include here, and I only wish CEDIA was more of a Consumer Electronics Show [open to the public] like CES that they have in the US.

Mark

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The ISCO DLP CINEMA LENS

I recently got to have a look at a Barco 3 chip DLP D-Cinema projector and admire a truly amazing piece of engineered hardware - the ISCO 1.25x stretch anamorphic lens that is used with this projector.

The lens is 1.25x stretch, not 1.33x because the projector's DLP chips are 2048 x 1080, not 1920 x 1080 as is used in HT. Therefore less optic stretch is required to reach the desired 2.37:1 image.

This lens is HUGE at 150mm across and it weights over 10KG...

Mark

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Looking towards a new HORIZON

The HORIZON is an Australian designed and engineered anamorphic lens designed for Home Theatre Constant Image Height applications requiring 1.33x Horizontal Stretch.

HORIZON in front of a SONY WV60

This 4-element cylindrical lens design has fully corrected optics and with the focus adjustment, produces perfect focus in both the horizontal and vertical directions.

Screen shot of pixels

These captures are of the pixels of a 1080 projector taken from the bottom left hand corner of a 150" Scope screen. Each row of the vertical images is just one pixel (1.8mm) wide! Very impressive stuff...

Mark

PLEASE INQUIRE HERE

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Solid Cherry Home Theatre Seat Cup Holders

http://www.hometheaterdiscussion.com/cupholders.html

These can be ordered by clicking directly on the link.

Mark

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MK3 Screen Shots

Just a tease. Screen shots from the new MK3 using achromatic doublets [CA corrected prisms]...

Mark

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