powerdome®VELVETFulldome Projection System

Technical Description

We make it visible.

Carl Zeiss AG – Planetarium Division

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powerdome®VELVET – Technical Description

1 Why Ultimate Black is Important for Fulldome ................................................................32 DLP Technology .............................................................................................................43 VELVET 1600 projector ...................................................................................................54 Domeconfigurations .....................................................................................................75 Digigon Dome Projection Lens ..................................................................................... 136 powerdome®ImageGenerator ..................................................................................... 147 Installation and Projector Alignment ............................................................................. 178 Maintenance ............................................................................................................... 179 Specifications .............................................................................................................. 1810 Dimensions .................................................................................................................20

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Fulldome relates to auditoriums – in most cases

planetarium theaters – in which images and videos are

projected onto a dome, i.e. a screen of spherical curva-

ture. Fulldome projection has been established in many

planetariums around the world. It offers, in addition to

the classical planetarium projection a great variety of new

presentation possibilities.

The development of fulldome theaters resulted from

the desire of planetariums to integrate large-format to

dome-fillingvisualizationsintopresentations.Theframe-

less view a dome provides to viewers immerses them

right into a virtual world. After more than ten years of

development, fulldome applications are still found mainly

in planetariums, i.e. with astronomical contents. It is very

slowly that fulldome is getting established as a medium in

its own right. Fulldome has the potential to address topics

ofanykind,whetherscientific,educational,culturalor

artistic. The spectrum ranges from “sky tonight” live shows

totrue-to-lifevisualizationsandentertainmentshows.

Fulldome projection covers the entire hemispheric

screen, with the objective to provide the impression of

a homogeneous image throughout the dome area. The

image projected onto the dome is synchronously assembled

from several partial images. Each partial image is generated

byadifferentprojectorandcoversanexactlydefinedseg-

ment of the dome. The greater the number of like projec-

tors, the greater is the brightness available for fulldome

projection. Also, the greater is the number of pixels and the

higher is the resolution. The projectors are arranged at the

horizon,asarule,projectingtheirrespectiveimagestothe

diametrically opposite side of the dome. But they may just

as well be arranged at or near the dome center. Carl Zeiss

fulldome systems are based on multichannel projection to

make use of the advantages of higher resolution and bright-

ness.

The fulldome projection system generates pixels from

digital computer data, which are issued to graphics boards

at a certain frame rate. The graphics boards convert these

dataintoastandardizedformat(videointerface)thatcan

be processed by the projectors. The imaging devices of

the projectors generate the pixels accordingly by varying

brightnessandcolor(modulation).Theprojectionlenses

projectthepixelsontothedomeatapermanentlysetfield

of view.

Fulldome Projection Systems for Dome Theaters

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Standard video projectors of any kind do not provide a

pure black background, where the image signal is off. The

projection background always keeps visible due to a more

or less gray in the image. While this is acceptable in the

conference room, it is extremely critical in a dome projec-

tion theater: the gray background framing the imagery is a

visiblenuisancethatspoilstheillusionofanobjectfloating

in space. In a planetarium, the gray background of a video

projection ruins the captivating brilliance of the starry sky,

the most important planetarium projection. At the edges of

theprojectionfieldsinmulti-channelfulldomesystems,the

grayishbackgroundofeachfieldsumsupduetotheedge

blending, which causes visible blends.

For the excellent match of opto-mechanical and digital

planetarium projection ultimate black of the image back-

ground is a of highest importance.

Black is the most critical color for brillant displays in planetarium projections.

Carl Zeiss developed the perfect solution with its

powerdome®VELVET fulldome projection systems. VELVET

is a video projector Carl Zeiss has specially designed for use

in domed auditoriums. It is the only projector on the market

that delivers a contrast ratio comparable with that of Carl

Zeissglass-fiberstarprojection.Withpowerdome®VELVET,

CarlZeissoffersafirst-classfulldomevideosystemwithan

absolutely black backdrop – for convincing and exciting

images.

Why Ultimate Black is Important for Fulldome

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The VELVET projector is based on the DLP® technology

of Texas Instruments. It is the only DLP projector on the

market that deliveres absolute black where black is in the

image.Theterrificon-offcontrastratioof2,500,000to1

is the highest contrast in digital projection ever achieved.

This contrast is comparable with that of Carl Zeiss glass-

fiberstarprojection.Blendsbetweentheimagechannels

are invisible. The high contrast also results in higher satu-

rated colors. The ultrahigh-contrast and colorful projection

is perceived by the eyes as extremly brilliant, pin sharp and

pleasant.

In the VELVET projectors, chips with 4 million micro

mirrors are at work. In DLP projectors, the image is cre-

ated by microscopically small mirrors laid out in a matrix

on a semiconductor chip, known as a Digital Micromirror

Device(DMD).Eachmirrorrepresentsonepixelinthe

projected image. These mirrors can be repositioned rapidly

toreflectlighteitherthroughthelensoraway,resulting

bright or dark pixels. Colors are produced by a controlled

spinning color wheel in front of the DMD device.

Why DLP Technology meets the requirements for fulldome projections best

The DLP technology of Texas Instruments is tried and

approved several million times. The technology is much

more stable than other projection technologies. Unlike

other technologies, which suffer a noticeable drop of

color saturation and homogeneity after a few thousand

operating hours, VELVET lets you enjoy superb images

much longer. The image appeares particularly sharp. The

DLP technology displays a very uniform image with regard

tobrightnessandcolors.Thankstosequential(instead

ofparallel)colormixingofthesingle-chiptechnologyno

overlap errors occur.

Long lifetime is essential for fulldome displays in plan-

etariums and dome theaters. Replacing video projectors

after two or three years is not an option for most of the

users. Home cinema and business projectors are designed

for a lifetime of few years only. The VELVET design is dif-

ferent. The Texas Instruments DMD chips as well as the

optical and mechanical projector design by Carl Zeiss will

serve for many more years. Implementing many engineer-

ing and design solutions, Carl Zeiss has designed this

projector for a working life of at least ten years, and with

low maintenance cost at that.

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3 VELVET 1600 Projector

High-resolution DMD chip technology with unmatched

contrast

VELVET is a Carl Zeiss in-house development. The

projector employs the WQXGA chip technology and

operates with 1600 picture lines. The contrast enhance-

ment is based on special optics designs developed by

Carl Zeiss, which exclude scattered light and a gray back-

ground from the start. The measurable on/off contrast

ratio reaches 2,500,000 : 1. This value is implemented

intheimageandhasbeenverifiedbymeansofcertified

measuringequipment.VELVETdeliversahigh-definition,

steady, brilliant image as known from common DLP pro-

jectors, but with a completely black background.

Illuminating system

Besides the DLP imager the illuminating system is of importance for excellent fulldome projection. In the VELVET projector

the lamp is separated from the image generator. The light source is specially arranged so that oblique installation positions

in the domed auditorium are possible without reducing the lamps’ lifetime. Lamp change is accomplished quickly and easily.

Thedesignoftheprojectorallowsfordifferentilluminatingsystemsdependingontheoptimallightoutputforspecificdome

sizesandprojectorconfigurations.

BrillantColor™

VELVET uses a six-segment color wheel and em-

ploys the latest BrillantColor™ technology by Texas

Instruments.Utilizingthespectrumoftheprojection

lamp(s),thistechnologyexpandsthegamutofcolors

and improves color saturation. It permits mixing of other

primarycolors(ase.g.cyanandyellow)inadditionto

red,greenandblue.Thisreducesmutualcolorinflu-

ences and excludes the color break up in fast scenes,

sometimes experienced with conventional DLP technol-

ogy.

xy Colorspace VELVET CIE(1931)

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8

x

y

red

green

blue

white ref 6500K

HDTV 709

VELVET projector with mounting and adjustment frame.

The color space of VELVET exceeds the HDTV norm.

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Ultimate contrast and saturated bright colors (real photograph of VELVET projection).

Stunning images on the dome (real photograph of VELVET projection).

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4 DomeConfigurations

Configuration Options

Powerdome®VELVETisamulti-channelfulldomesystemcomprisinganumberofprojectorsdependingonthedomesize,

brightnessandresolutionrequirementsandpossiblearchitecturalrestraints.Projectorlocationsandinstallationspecificsvary

withdifferentdomes.Thesystemisavailableforflat(horizontal)domesaswellasfortheaterswithtilteddomes.Ingeneral,

there are a number of projectors equally spaced around the perimeter of the dome producing the panoramic part of the

fulldomeimageandanadditionalprojector(ormore)aimedtowardthezenith.Projectorsshallbearrangedbelowthedome

springlinewiththeoptionofmountingoneormorewithinthetheatre(closetothedomecenter,atthecontroldeskorin

other suitable places. Alternatively the projectors can be mounted behind the dome screen at the lower edge. Small open-

ingsofapproximately120mm(5in)diametershallbeprovidedfortheprojectorlenses.Therathersmalldimensionofthe

VELVET projectors saves space behind the dome.

VELVET Duo intended for smaller domes consists of two projectors. Basically the number of projectors depends on the

domesize.Formediumsizedomesastandardconfigurationwith5to6projectorsprovidesbrightandhighlyresolved

fulldome images. For larger domes additional projectors will increase the brightness as well as the effective resolution on the

dome. In the case powerdome®VELVET will be used in

combination with an optical-mechanical planetarium projector in the center of the dome, the panoramic

fieldswillbeprojectedatanangletoavoidshadowsbytheplanetariumprojector.

CarlZeissdoesconfigureeachsystemindividuallytomeettherequirementsofaspecificdomeinthebestpossibleway.

Basic Configuration

powerdome®VELVET configurations are available for domes of 6 to 25 m in diameter.

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Initsbasicconfiguration,powerdome®VELVET

consists of six projectors, mounted in cove space below

the dome springline. Five projectors are covering the

panoramaareaandoneiscoveringthezenithfield.

CarlZeisswouldfinalizetheexactprojectorlayoutafter

direct consultation with the client’s specialists. An ar-

rangement of six VELVET projectors will already achieve

a resolution for 4.2k video output.

Schematic theater layout with basic configuration of six VELVET projectors.

Typical projector placement below the springline of the dome (front: panorama field, back: zenith field).

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Basic configuration with six VELVET projectors (typical arrangement, projectors not drawn to scale).

Different colors represent different projection fields on the dome screen. The red cross marks the optical axis for the respective field. Blending zones are not shown.

Projection fields with VELVET basic configuration from different perspectives.

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VELVET projector configuration for a medium size dome combined with a SKYMASTER ZKP 4 planetarium projector.

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VELVET Duo configuration with two projectors at the dome center and ZEISS SKYMASTER ZKP 4 planetarium projector.

VELVET Duo configuration with two projectors at the dome periphery.

VELVET Duo

Thenumberofprojectorsandthereforeimagechannelsforacertainfulldomesetupisnotfixed.Differentconfigurations

shallbeappliedtodifferentdomesituationsdependingonthedomesizeandthereflectivityoftheprojectionsurface,the

available space for the projectors and the consideration of a central star projector, where applicable.

VELVET Duo is designed for domes preferably of 8 m to 12 m in diameter featuring two VELVET 1600 projectors. It excel-

lently complements the ZEISS SKYMASTER ZKP 4 planetarium projector. Projection is either from the center or from the

periphery of the dome. Center projection has been conceived

as a supplement to the planetarium projector. Carl Zeiss provides common planetarium control of VELVET Duo and

SKYMASTER ZKP 4 with powerdome. VELVET Duo can be integrated into any existing planetarium installations, no matter

what model or make of planetarium projector is installed at the dome center. The two projectors are arranged at an angle of

180° relative to each other.

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VELVET projector configuration for a 20 m dome with eight projectors.

Other VELVET configurations

For theaters with dome diameters of 18 m and up, the number of projectors and thus image channels can be increased to

achievehigherbrightnessandresolutiononthedome.CarlZeisswilldesignthelayoutbasedonthespecifictheater.

Thefollowingparameterswillbetakenintoaccountinthedesignofaspecificconfiguration:

•domesize

•reflectivityoftheprojectionsurface

•requirementsonbrightnessandresolutiononthedome

•projectorplacements(availablespaceandpossiblerestrictions)

•centralplanetariumprojector(fixed/onalift)

•budgetconsiderations.

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5 DIGIGON dome projection lenses

To optimally satisfy requirements for dome projection, Carl

Zeiss equips its projectors with specially designed, dedicated

dome projection lenses only. The latest design is the DIGIGON

series with DIGIGON 2.5/50-80 lenses for multi-channel

systems and DIGIGON 178 and 140 lenses for Duo systems –

created specially for the VELVET projector.

DIGIGON lenses meet the most exacting demands on

contrast and imaging quality, furnishing brilliant, sharp projec-

tions. Consistently high quality of the lenses is ensured by

meticulous in-process measurements and adjust-ments.

Thanks to the exceptionally black background delivered

by the powerdome®VELVET projectors, the DIGIGON lenses

needs no geometric diaphragm to improve blends between

theimagefields.Thatiswhybrightnessacrossedgeblendings

is notably uniform. Edge blending is calculated in real-time by

the powerdome®ImageGenerator.

DIGIGON 2.5/50-80 Vario dome projection lens.

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6 powerdome®ImageGenerator

The powerdome®IG is a multi-channel graphics cluster for fulldome video, images and sound generation and to merge

opto-mechanical with digital planetarium projections. A master computer with integrated 5.1 sound application directs the

graphics cluster comprising high-performance graphics computers. Each projector is connected to one graphics computer via

opticalvideocable(DisplayPort).Theinternalnetworkservesforthecontrolofallcomputersandtheprojectorsinsynchro-

nization.Alldatafordomepresentations(video,images,sound,etc.)arestoredononeNetworkAttachedServer(NAS),

included in the network.

video signal

KVM

network

netw

ork

Master

Client 1

Client 6

Client 5

Client 4

Client 3

Client 2

NAS

VELVET projector

VELVET projector

VELVET projector

VELVET projector

VELVET projector

VELVET projector

Cluster and projector network diagram.

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The powerdome®IG is a convenient tool, which makes creating, editing and running fulldome planetarium shows easy.

Optionally an ergonomic panel for convenient manual control and a mobile device for wireless remote control are available.

With powerdome, all image distributions to the various channels, distortion correction, brightness and gamma adaptation

as well as the calculations of the channel blendings are effected in real time, without prior slicing.

planetarium control * powerdome master

keyboard / mouse

wireless remote control*

X-box *

powerdome ShowManagerpowerdome Player

powerdome ConfiguratorUniview*

powerdomeclients

(graphic PCs)scalable number

NAS

VELVETprojectors

scalable number

keyboard / mouse *

SKYPOST **STARPOST **UNIPOST **

control

video

contr

ol

data

planetariumuser

interface *

powerdomeuser interface /

fulldome preview

planetarium control panel *

dome

Typical powerdome hardware and software layout (*options; ** alternatively STARPOST/UNIPOST).

Itisabsoluteeasytointerferewitharunningshowthroughfamiliarcontrolcommands(Play,Pause,Stop,etc.).Itispos-

sibletojumptopredefinedbookmarksandchapters.Bymeansofatimepointeronecanmovetoanypointoftimewithin

a show and start projection there. Powerdome also allows for general control commands, such as for controlling the dome

illuminationandconfiguringtheprojection.

Powerdomemakesiteasytocompileownshows.Youmayeitherusedatafiledinanexistingdata-base(astronomical

objects),orintegrateimages,panoramas,videos,sounds,etc.Theoperatorinterfaceresemblesvideo-editingorcompositing

software and becomes familiar quickly. With the aid of a timeline and any number of levels and tracks, you can drag & drop

images and videos to any position on the dome or project them as fulldome images. Working with image alpha channels is

just as easy as the integration and animation of textual matter.

A special feature of powerdome is the time-line view. Here, the various media objects are shown as bars at different lev-

els. The elements are arranged according to their succession in time or their start and end times. The time bar view provides

alucidoperatorinterface,whichpermitsextremelyeasyorganizationandmodificationoftheshowobjects.Eachelement

can be dragged with the mouse to any point in time within the show, and its playing time can be expanded or contracted

just as easily. Related objects can be grouped and animated in common. The time scale can be expanded or contracted to

allow detailed editing or provide a better overview, respectively.

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The powerdome®IG permits the following elements to be integrated in any show.

•all-skies

•panoramas

•singleimages(photographs,graphics)

•fulldomevideo

•standardandHDTVvideo

•audio

•3Dobjects,animated

•text/labels

•starsandskymotions

•sun,moon&planets

•classicalplanetariumfunctions(e.g.meridian,ecliptic,etc.)

•self-definedlines,grids,scales

•controlcommands,projectdependent(e.g.shutteron/off)

The powerdome software allows for playback and real-time presentations. To play a compiled show just press the Play

button.

For real-time operation, a standard planetarium control panel with keys and rotary knobs is available. This allows to use

powerdome as digital planetarium and to combine opto-mechanical projectors with powerdome presentations in synch. User

inputcanbemadeviaamobildevice(option)aswell.

It is possible to play back a compiled show while at the same time integrating additional astronomical objects. For

example, a show prepared with powerdome can be played back and stopped in between in certain places to add various

astronomical objects to the presentation. It is also possible to add astronomical functions during a running show.

In combination with opto-mechanical planetariums powerdome is linked to the planetarium control computer. Thus, all

manualandautomaticexecutionsoffunctionsandshowsaresynchronized.Forinstance,theoverlayofconstellationout-

lineswithpowerdomewillrigidlyfollowallmotionsoftheopto-mechanicalstarfield.Bothsystemsworkasone.

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7 Installation and Projector Alignment

Installation and alignment of the projectors will be carried out by Carl Zeiss service engineers during the installation of

the overall system. According to projector alignment and dome geometry a test grid will be delivered. The test grids for each

projector will remain with the customer, so that the projector alignments can be checked and, if necessary, readjusted at

any time. For coarse alignments, suitable adjustment elements are provided on the projector and on its mount. Furthermore,

automaticcalibration(option)offersatoolforpixelaccuratefineadjustment.

The optional automatic calibration is based on a set of cameras equipped with wide-angle lenses. All cameras will be rig-

idlyfixedatthedomeperiphery.Theautocalibrationsystemallowsgeometryadjustmentsforsinglechannelsaswellasfor

the entire display system by a single mouse click. The underlying software restores the original image quality. Calibration may

become necessary with changes to projector placements after lamp changes or simply by bumping into it.

8 Maintenance

The projector is nearly maintenance-free. Just the lamps, affordably priced, need to be replaced after approx. 2,000 h.

Costs of operation are therefore lower than with many other fulldome projection systems on the market.

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9 Specifications

9.1 Overall SystemTechnology Texas Instruments DLP® Technology and

Carl Zeiss True Black Projection Technology

Dome diameter 8 – 25 m

Dometilt 0°–30°(deepertiltonrequest)

Numberofprojectors 2(Duo),6(basicconfiguration),8+(differentnumbers

dependingonproject)

Number of image channels same as number of projectors

Resolution 3k to 5k

Projectorposition Domecenter(Duo),Domeperiphery(Duo,basicconfiguration,

customizedpositionsdependingonproject)

Projectionarea 360°x180°(alsosuitablefordomeswithlessthan180°)

Gain of projection surface 30% to 50% recommended

Operatingtemperature +18°C...30°C(64...86F)

Rel.humidity 70%to85%(w/ocondensation)

Operatingvoltage 100-240V,50/60Hz

Power consumption approx. 5.5 kVA

9.2 VELVET 16000 Projector Technology Black Projection Technology by Carl Zeiss

Imager LVDS DMD™ with DarkChip3™

Imager resolution 2560 x 1600 native

Color rendition 30 bit RGB

Projectionlens DIGIGON178/140(Duo)2.5/50-80Vario(multi-channel)

Iris diaphragm 0 - 100% controllable

Brightness single lamp: 1300 lumen, dual lamp: 1900 lm

Contrast(on/off) 2,500,000:1

Edge blending electronic blending by powerdome®IG

Powersupply 100-240V,50/60Hz

Powerconsumptionperprojector approx.650VA(singlelamp),approx.1,000VA(duallamp)

approx. 50 VA stand-by

Heatoutput approx.2,200BTU/h(singlelamp),

approx.3,400BTU/h(duallamp)

Color mode standard: 8 bit RGB; deep color mode: 10 bit RGB

Cooling air cooling

Width x height x depth approx. 674 mm x 729 mm x 500 mm, incl. lens and mount

Weight approx. 75 kg, incl. lens and mount

Lamp 330WP-P-VIP(obtainablethroughlocaldealers)

Lamplife target2000h,typical1500h(regularmode)

Lamp per projector SL: 1, DL: 2

Input signal 1x DisplayPort digital RGB

(nointernalscaler)

Control interface 1x RJ45 TCP/IP network port

Operatingnoiselevel approx.50db(A)single,approx.58db(A)duallamp

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9.3 ZEISS DIGIGON Projection Lenses

Type 178 140 DIGIGON 2.5/50-80

Projection angle 178° 140° 50° to 80°

Correction for curved image plane

9.4 Control Computer

Type Industrial PC

Operating system MS Windows, English

Inputdevices keyboardmouse,(wirelessmobiledeviceoptional)

Communications TCP/IP

Remote control/checks prepared

9.5 Cable

Power cable 1 set

Network cable 1 set

Video cable 1 set

9.6 powerdome®IG

System architecture PC cluster

PCversions IndustrialPC(19”)

Accommodation 19”PCrack(1to3racks,numberofracksdependingon

configuration)

Configuration MasterPC(1x),clientPCs(numberaccordingtoimagechannels)

Network 1 GB Ethernet

Data storage NAS Fileserver, 4 TB or more

Sound 5.1 SPDIF

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10 Dimensions

10.1 VELVET projector with DIGIGON 2.5/50-80 and adjustment frame

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Carl Zeiss AGPlanetarium Division07740 JENA, GERMANYPhone: +49-3641-642406Fax: +49-3641-643023e-mail: planetarium@zeiss.dewww.zeiss.com/planetariums

Publ. No.: EN_58_022_357IX04/2013

We reserve the right to change specifications in the interest of technical progress.