Posted on September 6, 2018 | by Guest
Today classroom projectors are the key components of the top digital educational spaces. A portal to engage media where every student can be focused and can actively participate. If only choosing classroom projector were as simple as picking up a book. There are so many factors that have to be considered before making the decision. Let’s have a look at 6 of most critical factors.
For example, in a classroom where the last row of seats is set at 72 feet from the display wall, the display height would be 72*(1/8) i.e. 9 feet for general viewing. Similarly, for detailed and inspection viewing. Once the display height is determined, the width is set by the aspect ratio of the image. A widescreen ratio of 16:9 would suggest a 16 feet wide screen.
Background light in the classroom can cause the image to become washed out. Since background light determines contrast, it is also a major factor in making the right projector choice.
Under normal usage, brightness of a projector will decay to 80% after usage of 6,000 hours (approximate 3 years). The following table will prove handy in gauging the recommended projection brightness.
Today, interactive classroom projectors can turn any surface into an interactive whiteboard. Multi-touch capability for pens or fingers can be used in conjunction with the projection surface to create collaborative learning possibilities. BenQ classroom projectors come equipped with PointWrite™ technology and QWrite software to achieve this collaboration. In QWrite Whiteboard Mode, professors can also run different applications or display, view, and annotate across two surfaces.
BYOD – Bring your own Device
BYOD is gaining ground quickly in higher education. Not only does it encourage collaboration between teacher and students, but also amongst students. Thus, adding peer learning to the learning mix. Another advantage of BYOD is that it leverages the existing ‘device’ environment of the students to deliver lessons
BenQ interactive classroom projectors are all built to enable BYOD environments. Apart from wired MHL support, BenQ education projectors create more engaging lessons via QCast wireless dongle that allows up to 4 participants to stream content from smart devices or computers to the big screen, displaying them in 4 split screens. Cool, right?
Posted on April 13, 2018 | by Vinod Kakumanu
Furniture in the classroom can enhance or diminish the learning environment. Classroom furniture must be arranged in such a way that the teacher is visible and audible to every child in the classroom. In playschools, the children are supposed to be mobile in the classroom and play outdoors for a comparable amount of time. In elementary schools, there are students who are learning to be sedentary and concentrate on instructions being given by the teacher. School furniture must be appropriately designed for the age and the stage of physical development of the children constituting the class.
The influence of the teacher on the students is subtle and it must be ensured that the design of the furniture does not diminish the attention of the child by discomfort or restricted freedom of movement. The choice of correct furniture for early schooling i.e. preschools and elementary schools becomes extremely important in this regard.
Children in early developmental stages learn not just from their teacher but also from the environs composed by the surrounding space and its configuration. The classroom’s furniture is integral for the creation of an environment for the children to imbibe learning and discover the nature and utility of the material that surrounds them and achieve physical and mental independence in the process.
Classroom Furniture aids in early development
For a three or five year old child being sedentary and concentrating is a new experience. Sitting attentively at a stretch of half an hour is something to be acquired, it does not come natural. Classroom furniture is instrumental for learning to take interest in verbal and non- verbal information while being stationary. It is only rational to expect then that the furniture, the work table, chair or the bench are comfortable and safe inasmuch as they become extensions of the child’s body. The chair that lets the child place his or her feet on the ground beneath and a shared bench which let him or her move without inconveniencing the one sitting next. And the table which is spacious enough to let him spread paper or material while he or she engages creatively with them are requisite for designing a creative learning environment. Single Seater Desk and Chair, Double Seater Desk and Chair, Learner Desk And Chair, Genius Double Seater are ideal for creating a perfect and collaborative learning space in preschools and elementary schools
These furniture sets are designed to accommodate the children as best as possible while sitting and listening as well as while working with their hands. There are lot of indoor activities in which children are required to move their arms and bodies around. The furniture selected for the playschools and elementary schools must provide for that in their design and size. The floor must be within the reach of the child’s feet for increased stability. Dangling feet inhibit concentration of the children and make it hard to conduct activities. The posture of children is an important consideration. The furniture must support the back well. The adjustability of the furniture especially the chairs must be given premium as there are children of different heights in a single classroom. The arrangement of the chairs or benches of the children must not hamper the movement of the teacher in the preschool and elementary classrooms as the teacher is required to give individual attention to the children in such early stages.
Trapezium shaped tables and Front Round Tables are ideal for elementary schools and differently shaped tables like Apple shaped tables go beautifully with the preschool environment.
Classroom Furniture should give the child Structure and Composure
The learning space that is primarily structured by the furniture followed by other furnishings. Stuffing the classroom results in stifling congestion and poorly selected furniture for preschools and elementary schools end up in a classroom with chairs that are either too small or too big for the child. The furniture should be selected keeping in mind the curriculum and the classroom activity it entails. There should be absolutely no room for tables that shake when the child is learning to write his first letter or structuring his first sentence.
Attention must be paid to the texture and color of the furniture, the designs the borders etc. The sitting arrangement in the group activities or lunch must be kept in mind while selecting furniture for the early classrooms which are the places of pleasant exploration.
Fixtures must be avoided in the preschools/playschool, daycare and elementary schools. The furniture must be movable and even portable. When the arrangements for a group activity, music activity, and games are to be made single piece pleasantly colored plastic chairs, round tables with chairs, square tables, rectangular spacious tables are needed.
Smooth single desk and chair set available in different sizes for the art room of the preschools and the elementary schools.
Keeping the child psychology in the developmental stages which is very responsive to the subtle changes in the environment, it is preferable to use different colors and designs, and of course sizes, for higher classes to which the child graduates. Sr. Desk and Chair set can be used in the senior classes of elementary schools.
Furniture must be selected for accommodating varying numbers of children
The classroom furniture for preschools and elementary schools must be selected keeping in mind that the strength of the class may vary frequently. To accommodate more children without compromising with the curricular activities it is best to equip the class with composite table sets like Little Fingers Desk and Chair, Maestro Desk and Chair. Preschools can also opt for Plastic Handle Chair to accommodate growing number of children.
Besides the furniture of the classroom, there are also other furnishings which are not to be considered superfluous. We are talking about the storage facilities. The children may be able to keep their artwork, toys, material etc. if a Book Shelf is provided. The daycare and preschools also require furniture that includes Children’s Cot.
Commissioning furniture for preschools and elementary schools must be done with precision and after considering the recommended curriculum of Montessori schools and Waldorf schools. If that is done the preschooling will become extremely purposeful and elementary schooling will become the foundation to reckon with.
Posted on April 12, 2018 | by Vinod Kakumanu
Affordable computing technology options are being applied across organizations including schools. The technology that has gained prominence in the search for affordability is Virtual Desktop Infrastructure (VDI). VDI is a virtual computer technology, terms like ‘Thin client’ and ‘Zero clients’ are synonymous with virtual computing. In a VDI computing setting, administrators can minimize the number of real PCs or blades and operate several virtual PCs on server class hardware deploying Thin Clients or Zero Clients.
Thin clients and zero clients are the devices that enable several users to share a computer simultaneously. Modern computers are powerful enough to cater to more than one user at a time. VDI helps a set of end users utilize the unused computing power through thin clients or zero clients. These devices enable the organization to migrate to the virtual computing environment. With the use of VDI, that is actually centralization of computing, the IT ownership cost of the school becomes very economical as it does not involve buying several new PCs but opting for single VDI server for thin or zero clients instead.
The technology with the use of Zero Client and Thin Client desktops puts into effect desktop virtualization infrastructure. Desktop virtualization happens when the software is separated from the thin client or zero client instrument. This helps in remote accessing of the data over several different devices by N number of users and curtails the vulnerability to the malware. This provides a considerable flexibility in the work culture. All the software and data are not fed into a single device, disaster recovery is considerably easy in VDI.
Desktop virtualization has many implications including the reduction in the cost of computerization firstly by doing away with the need of installing individual desktops, or Fat Clients, and then by cutting the cost of maintenance and decentralized software up gradation. Functional benefits of desktop virtualization include the enablement of remote access to the data by the user. Virtual computing environment would include N computing device, thin or zero clients and the virtualization software for installation on the server.
With the aid of VDI, N number of users equipped nothing, but a keyboard and mouse and monitor can log in to a centralized operating system. Thus, it follows that in a virtual computing environment only a server needs to be maintained instead of several different PCs for reliable backup and storage. The anti-virus protection is also centralized in case of such computing applications.
Desktop Virtualization capacitates the enterprise to replace the Desktop PC with a device with fewer components to fail and that have lower power consumption liability. It must be stated that the virtual desktops including thin clients and zero clients are no less efficient than computing system built on array of several PCs.
Virtual computing devices come in ultra-small size or form factor like Ncomputing L300 with the virtualization software. Thin client and Zero Client vendors include Thinvent, ICTS, Ncomputing, Digi International, Pano Logic Inc., Teradici, Via Labs and Wyse Technology.
Thin Client and Ultra-Thin Client (Zero Client) devices are basically small sized computers that are made to be used in remote server-based setting. Major portion of the work is centralized in the server. It includes processing software programs and storing data. Thin client function is opposed to the Fat Client or a conventional computer in that in the latter’s case the functions are performed locally. Thin Clients compose VDI which several end users can work on using the same server. This puts in place a centralized computing scenario with greater security in lesser cost.
It must be noted that before making a transition from a desktop PC based computing environment to a Thin Client or Zero Client- Server based centralized computing environment, there are certain considerations. If these are not observed the benefits of Thin Clients and Zero Clients may not be fully actualized.
Multimedia delivering capability
It is seen that the Thin Clients and Ultra-Thin Clients do not fare as well as the desktop PCs when it comes to multi-media usage. In a server-based computing environment the audio, video data on a thin client may lack quality. The problem lies with the optimization levels of the real time traffic through display protocols like Independent Computing Architecture and Microsoft’s Remote Desktop Protocol. There is also an issue with the remote display protocols’ support for high definition images in environment built on several monitors.
Fortunately, progress has been made to overcome these limitations. Wyse’s TCX Multimedia software has the capability to improve the multi-media experience of the thin computing architecture. Citrix’s High Definition User Experience Technologies (HDX) has the capability of delivering real-time audio and video as well as higher graphics.
It is important to set a clear criterion for checking adaptability of the thin clients and zero clients to the technology that enables them to access better multi-media experience.
Reliability of the Network
The thin client and zero client computing environment depends on consistent connectivity between the server and the thin client. To ensure the continued access to the server the robust LAN/WAN is indispensable.
Local Device Access
Thin client devices’ support for local device access has been reportedly not comparable to the fat client. It is known that the centralized computing environment does not lend itself generously to the local devices. The local devices consist of USB devices including cameras, scanners, video capture devices, remote drives etc.
There are solutions to satisfactorily resolve these issues too. Citrix HDX makes USB support satisfactory. Wyse’s TCX USB Virtualizer can be used to complement the Thin Clients for better compatibility for USB devices.
Utility for Mobile Users
Given the benefits we have dwelt upon already, it is apparent by now that thin client and zero client devices are ideal replacement for a desktop intensive computing environment. But in case there are number of end user working in silo on a laptop, the thin client replacement becomes something to be reconsidered.
There are technologies in thin clients including thin client mobile devices like Wyse X90 and Wyse X90e mobile thin clients and HP’s 4410t. In spite of the presence and usability of these technologies if there are end users who work off line on lap tops the thin client mobile devices’ deployment is of limited use.
However, if the laptops are being used as replacements for conventional desktops and not much for their mobility it is advisable to opt for thin clients or zero clients as replacements.
The thin clients or zero clients do not reduce cost if applied in isolation. Investments are also to be made on Thin Client Solutions that we have discussed above and virtual desktop infrastructure connection broker solution with Microsoft Licensing. The replacement cannot be wholesale, it must be selective. Then there are solutions to turn existing enterprise desktops into thin devices.
In conclusion, it must be said that thin clients and zero clients reduce significant cost, enhance security besides reduced IT management liabilities.
Posted on April 11, 2018 | by Vinod Kakumanu
Inanimate objects form an important part of the inventory of the Elementary Schools. They do so for a simple reason that works on a complex mechanism—they boost imagination and the learning to relate to objects. They engage the children better and improve the span of concentration which is naturally low in small children. They also make children proactive in a learning environment.
Montessori education method leads in the use of material in early schooling and other education philosophies follow suit. Objects, educational material and other related educational aid enhance the appeal of the learning environment and makes imparting of any lesson playfully easier. Children’s communication and emotional intelligence is stimulated when they are surrounded by objects they can manipulate while learning. Theory of multiple intelligence’s also recommends amplification of lessons through simplest educational aids i.e. objects and stories woven around them. And when it comes to educational use of material, it is best to employ handy figures representing farm animals etc.
It is important to procure material whose use in the early classrooms and their effect on child’s psyche is researched. Choice of material must not be random and must not be guided by the market either. It must be ensured that there is a variation of toys and material and there must be enough of them for each child to have some to explore. Touching is important for the brain development and for acquiring finer motor skills, hence it can be said that toys and other objects are requisite material for any preschool. Genuine Montessori material is designed according to the specific educational principles.
Montessori materials for preschools must be select and bought from sellers who supply objects made from materials like fabric, wood and clay. A series of objects and hand puppets are available for use in preschools that promote sensorial growth and development.
The learning material for early schooling is also crafted keeping in view the educational ideas of Montessori philosophy. The teaching-learning is centered around these thematic materials that include puzzles, blocks, thematic representations etc. The selectors of these material must follow certain criteria which are discussed as under-
Design must appeal to child’s mind
The children in the classroom will have freedom of movement and they will interact with the objects that fill the room. The objects must be of visually appealing designs and diverse textures—wood, fabric, enamel etc. The environs may also contain some naturalistic objects like simulated bird’s nests.
The Montessori environment is about sequential learning in a natural way. The child in the environment manipulates the material and, with careful instruction, learns to use them creatively and carefully, learning to become independent in the process.
The games that are provided are not only intended to be playthings but are scientifically proven stimulants of learning in children. The games’ and the materials’ complexity increases sequentially.
Every learning material is designed to teach a particular skill or concept or stimulate a particular sense. They range from materials like hand puppets, picture pairing ’and‘ number blocks’
There is an in built “control of error” element in Montessori material that facilitates learning from error in children. Although an occasional hint from the teacher is required.
Different materials are designed for different developmental levels. They help in learning simple manipulation of materials and motor skills to more complex development of perspectives of size and measurement.
The material must stimulate activity
Educational philosophies like Montessori and Waldorf emphasize on movement. Movement is related to early learning and so the material placed in the preschool must invite children to act. They must provide opportunities for development of motor skills and coordination.
The material must encourage child to “build” and simulate tasks
The material that offers itself for “growth” or build up stimulates growth in children, enhance engagement and develop perception of order. Keeping this in view materials and apparatuses like block puzzles, ‘Horizontal Dowel Variation – Serpentine’, ‘Cubes on Vertical Dial’ are designed. The playschool indoors are also constituted by contraptions and materials that help the child simulate certain activities and role play. These include ‘cook and play’ sets, ‘get out and grill’, ‘side by side kitchen’, ‘cook and store kitchen’, Juice Making Set, ‘Cleaning Grains’ set ‘Sieving Set ‘Pounding In Steel’ , ‘Sponging Set’ and ‘electronic sound pumper’ etc.
The material should encourage exploration
The children at the preschool interact with material and get instructed by their teachers to comprehend how things work and the desire to explore the functions that a particular thing placed before them entails must be stimulated. Materials like ‘shopping cart’ a composite ‘workshop’, ‘gas pump’ and ‘super chef kitchen’ are certain equipment that are suggested for the purpose of stimulating a sense of discovery in children. In a preschool environment a child learns by self- exploration, observing the teachers and the also other children. The lessons need to be structured and for that the Montessori materials materialize the functionality. The array of materials is the medium of growth of the body and the mind.
Help learn concepts of language and Mathematics
Montessori materials that develops and clarifies child’s concepts through their innovative design have to be carefully identified and selected. Early acquisition of language and numerical ability are elementary in development of IQ. There are an array of Montessori materials that help in building concepts of mathematics and cognitive framework of language. The Montessori language material include ‘Alphabet Tray with Knobs’ , ‘Tracing Capital Letter’ stencil set and ‘Pattern Writing’ set ‘Say and Spell’, ‘Capital and Small letter Matching’ set etc.. These are extremely useful and playful instruments for initiating kids into writing. The special ‘Alphabet Phono Puzzle’ develop the auditory processing of language, its function is analogous to the ‘Alphabet and Picture Matching’ set which develop the language by visual association. Montessori language material is not confined to English. Hindi alphabet and numeral familiarity is also given a set of media through ‘Hindi letter to Picture Matching’,’ Hindi Numeral Tracing’ sets with similar sets for Kannada letters and numerals etc.
Montessori mathematics materials are equally diverse and fascinating, it includes introduction to calculation by ‘Junior and Senior Ariones’ set, Numeral Quantity Matching set, ‘Numeral Ring Stacker’ , Numerical Bead Stacker’ and Abacus type ‘Counting Frame’ etc.
Besides numerals and early introduction to calculation, concepts like time telling and watch reading can be introduced to kids through eduedge ‘clock set’.
Introduction to concepts of dimension can also be made fun and visual-spatial intelligence be stimulated through materials like ‘Shape Ascender’, ‘Follow a Pattern’, ‘Box with Square Prism’, ‘Tracing basic and Advance Pattern’ set.
The Montessori material is scientifically designed and it has been contrived in a way that catches a preschool child’s fancy. For children who have reached the developmental stage where concepts of language and arithmetic are introduced the above mentioned Montessori language and Montessori mathematics material make a great cache of learning aid for the purpose.
Posted on April 11, 2018 | by Vinod Kakumanu
Interactive whiteboard, also known as smart board is a 21st century substitute to the traditional black board. It is a mediating technology useful in turning the class increasingly interactive. It is a significant addition to the learning environment and a defining feature of educational technology for classrooms. The whiteboards have transformed classrooms, including that of primary and secondary schools across the developed world and have now entered the Indian classrooms. An Interactive Whiteboard for schools is basically an interactive display customized for the classroom teaching. With the use of the interactive whiteboard, a classroom with a single PC and projector can be turned into a more engaging multimedia learning space.
Among the leading manufacturers of Interactive Whiteboard are Smart Technologies, Promethean, MIMIO, Specktron and RICOHIndia.
The IWB can substitute for the use of mouse or keyboard and enable the teacher to conduct a presentation on its screen. The IWB is equipped with software to conduct interactive multimedia classroom and display online content integrated with the lessons in innovative ways. It makes the study of subjects ranging from geometry to geography much more content rich with visual imagery and hence many times more engaging.
An interactive whiteboard achieves efficiency in teaching and learning by a composite of whiteboard, touch and stylus pen and an LCD projector. The whiteboard has inbuilt software.
Mostly, in an interactive whiteboard configuration the interactive whiteboard acts as a computer screen and there is a projector which is mounted on the wall or on a stand. A particular software application can be chosen for the interactive whiteboard and it becomes an interactive screen visible to all the students in the classroom.
The teacher can use a PC connected to the projector to display the content on the whiteboard and speaker for audio. The content on the whiteboard can be manipulated by the teacher through the touch screen or a pointing device. Anything that ought to be done on a PC can thus be done on the interactive whiteboard itself.
With the help of the whiteboard, the teacher can make the lesson wholesome by incorporating videos, images, web pages and music etc.
Interactive Whiteboard’s use in the class activities
There is hardly any constraint to the expansion of the range of the classroom activities with the use of IWB. Class lessons can be enhanced through multimedia content. It can help the teachers in engaging the students by letting them conduct presentations of class projects etc. Students can be divided into groups and can relate their understanding with each other on any given topic. The interactive whiteboard can also be used by the substitute teachers to deliver a lecture prepared and recorded on the interactive whiteboard. The revision of lessons becomes several times easier with the use of the whiteboard. Animated figures, diagrams, maps and graphs displayed and compared on the whiteboard can enhance learning of mathematics, biology, geography etc. and virtual field trips can be arranged by using the interactive white board to integrate the imagination with visual memory of the students. It makes it easier to frame notes and distribute them to the students besides increasing the participation and concentration of the pupils.
What should school look for while selecting an interactive white board?
Size and Design
Interactive whiteboards come as fixed. There also are mobile interactive whiteboards. Generally, the fixed whiteboard are opted for by the schools. It is the optimal choice for the classrooms having considerable number of students. Mobile whiteboard with wheels are chosen by schools to economize as they can be moved from one classroom to another in a sharing arrangement.
Size and model of the whiteboard may vary from a desktop size to large blackboard comparable size, the size may range from 16 inches to 84 inches or more.
The selection depends upon the classroom considerations like, how one intends to use the whiteboard in the classroom? If the purpose is to engage multiple students in an interactive lesson and the aim is to use multiple applications, then a large size whiteboard is the ideal choice. For a small group of students or for only making engaging lessons and presentations a desktop sized whiteboard would suffice.
Besides the size and the model one must check for the availability of multi touch points and active projection dimension the other important attribute is the resolution that the whiteboard offers.
The Operating system of the whiteboard must be selected with attention to detail.
Interactive whiteboard is equipped with software. It can be called a software interactive whiteboard. Software for the IWB’s are designed for delivering different teaching – learning experiences. Software supporting touch and stylus pen are used for interactive discussions within the group, forming a digital narrative, lessons for specific topics of different subjects, real-time lessons and presentations. The interactive whiteboard can provide enough variety to accommodate the different learning styles of the pupils in the class. There are some other considerations like the Storage and operating temperatures.
Posted on December 20, 2017 | by Vinod Kakumanu
More than 150 companies manufacture over 6000 different models of projectors worldwide till date, of which more than 60 companies stopped manufacturing and more than 4500 models have attained End of Life i.e; no longer in production. It’s noteworthy to know that famous brands like IBM, HP, Compaq, Kodak, Philips, Olympus, Lenovo, Xerox, Zenith etc are amongst the 50+ companies that used to manufacture projectors in the past. Also it’s noteworthy that less known brands like Optoma, Benq, Epson, Taxan, Sanyo, Hitachi, NEC, Infocus, Mitsubishi along with Sony, Sharp, Panasonic are the largest manufacturers of projectors globally.
There’s such a wide choice of projectors available, we thought you might need some help working out which is best for you. So here’s a guide to the features you should look out for
Brightness is measured in ‘ANSI lumens’. Brightness is much less important for home cinema as there is an overriding assumption that the projector will be used in
a darkened room. So, for home theatre users, brightness should not be an issue (anything between 700 – 1200 lumens is sufficient). However, if there is a lot of ambient light and you don’t want to have to draw the curtains (or if your audience has to write their notes as in the case of classrooms), you may opt to go for something between 2000 and 3000 lumens. A projector can be damaging to the eyes if you look directly into the beam. The brighter the projector, the higher the chances of this being an issue. So, SchoolServ recommends 2000 to 3000 lumens for a typical classroom installation (for a 60 to 80 inch diagonal projected image). Also the bigger the projected image, the more brightness the projector should be relative.
The resolution is the accuracy of the image that the projector casts. Most projectors fall into two categories – SVGA (800 x 600 pixels) or XGA (1024 x 768 pixels) apart from few SXGA (1280 x 1024 pixels). These are the true or native resolutions for a given projector, but almost all the present day projectors are compatible to all resolutions through compression or enlargement, but at the cost of lower sharpness & image quality.
Home cinema users – please note the majority of dedicated home cinema projectors project a native 16:9 (widescreen) image and fall into one of three resolution categories – WVGA (854 x 480 pixels), WSVGA (1024 x 576 pixels) or WXGA (1280 x 720 pixels). The ‘W’ stands for ‘Wide’. (The best way to get the best output from a projector is by adjusting the computer/laptop resolution to the native resolution so that there is no loss of quality).
If you’re concerned about picture quality, don’t just look at the brightness. Contrast is just as important. The contrast ratio is the ratio between the white and black parts in an image. The larger the contrast ratio of a projector, the greater the difference between the brightest whites and the darkest blacks a projector can show. In short, it’s a measure of how well the projector can block out light from the lamp, i.e. how black is the black? A contrast rating of 1000:1 would imply that the black level is 1000 times darker than the white. This is especially important for home cinema applications. For Classroom application where there is more textual projection, a contrast ratio of 1000: 1 to 2000:1 is sufficient. However, for Home theatre application, we recommend a minimum contrast ratio of 2500:1
Data, Video & Audio Inputs
Depending on your requirement, you have to look out for different connections like VGA (RGB), S-Video, Composite Video, Component Video, DVI, HDMI, Audio inputs/outputs, Memory card slots etc. For a normal classroom application, a VGA connector is enough as most of the presentation is done through a computer. Even an audio input/output may not be required as you can connect your PC or video source to an amplifier or speakers so that the whole classroom gets enough audibility.
‘Keystoning’ is the name given to the effect on the projected image when the projector sits below or above the center of the screen. Keystone correction counteracts this effect by digitally compressing the image at the bottom or top, resulting in a squarer, more professional image. Almost all the present day projectors have digital keystone correction.
Lens shift is generally a feature of high-end projectors or specialist home cinema models. Lens shift has a similar effect to ‘Keystone correction’ except that the effect is achieved by physically adjusting the angle of the projector’s lens to square up the image.
Zoom / Short Throw Lens
Manual or digital zoom is a feature available on many standard lenses/projectors. The zoom feature allows for larger or smaller images from the same distance, much like a zoom lens on a 35mm camera. Most lenses have a zoom ratio of 1.0 : 1.10 – 1.20. Short throw lenses help create larger pictures from shorter distances. They are mostly used in environments like small conference rooms/classrooms, trade show booths, small home theaters. Also, short throw lenses are preferred to reduce the shadow. But again it’s a premium feature and comes at a price.
Lamp Hours, Wattage & Cost
Most of the present day 3LCD / DLP projectors have 2000 / 3000 hours to 3000 / 4000 hours (standard/economy modes) lamp life. Extra lamp costs 40 – 60% of the projector cost. Benq and Optoma projector lamps are little cheaper compared to other manufacturers. Most projector lamps have wattage in the range of 150 – 300 watts. For a classroom, where the daily usage is more, lamps with around 200 wattages are recommended so that electricity bills are under control.
Screen or Projection Surface
To get the best out of your projector, you should project it onto a surface/screen that will give you a better image quality in terms of brightness, contrast and color reproduction. You may probably need a 16:9 screen if you are using it for home theatre purpose or a gaming console.
In classrooms, particularly when you are using a multipurpose surface like whiteboard or glass board, you have to be very choosy in selecting a non-glare surface as most whiteboards including magnetic, P3 Ceramic boards do reflect the projector’s light. SchoolServ recommends its classroom tailor-made whiteboards (<1% glare) for use in classrooms.
Weight / Size
Are you taking your projector on the road or leaving it in the boardroom? If you are on the move, you’ll appreciate having a projector that’s as portable as you can afford. Leaving the pocket/home theatre projectors, regular LCD / DLP projectors are weighing from 1kg to 4kgs. For a classroom (particularly ceiling mounted), anything from 1.5kg to 3.0 kg would hold good.
Like all electronics, projectors sometimes break down. And when they get heavy use and are used in the classroom environment, the chances of this happening get greater. If your projector’s out of action then it could really affect your lesson plans. You want it up and running again quickly, so take into account the type of warranty, not just the length. Lastly, don’t forget to look at the warranty on the lamp as well as the warranty on the projector – they’re generally covered separately with a much shorter lamp warranty. In general, most manufacturers give 1 yr warranty on the projector and 3 months / 500 hrs on the lamp. Some give up to 2-3 yrs on the projector and 1 yr / 1000 hrs on lamp. Manufacturers who currently have strong warranty offerings include Benq, Optoma, Epson, NEC.
Obviously, you’d prefer to get your projector as cheaply as possible! Generally, XGA adds about 20 to 40 percent to the price of a projector, while brightness and portability are the other major factors. In a regular school classroom application, SVGA model may be sufficient (as you can set the pc’s resolution to 800 x 600 & there would be no loss in quality). Weigh up the features you need before buying to get the best value!
While the LCD projectors are the first generation projectors, 3LCD, DLP, LCoS projectors are manufactured presently. While LCoS (Liquid Crystal on Silicon) (adapted mostly by Canon & few others) is a new technology which can be told as a combination of LCD & DLP technologies, it is very expensive than other technologies with the advantage of exceptional picture quality. SXRD ( Silicon X-tal Reflective Display) is Sony’s proprietary variant of LCoS, mostly used for HD & Home theatre projectors from Sony. D-ILA (Digital Direct Drive Image Light Amplifier) is another variant of LCoS used by JVC.
3LCD and DLP are the technologies used by almost all manufacturers/models in today’s market
LCD or DLP. Until recently, LCD was reserved for less expensive designs while DLP models held the performance edge for high-end projectors. However, recent advances have seen both technologies converge and in most cases, there is less of a reason to pick one technology over another. LCD technology has improved (with 3LCD) in the last 2-3 years while DLP models are more competitively priced than ever before. So in short, both technologies are now able to offer crisp, clear and vibrant images, the main consideration to make on which projector is right for you is down to the more specific requirements such as brightness, resolution, contrast, and connectivity.
3LCD (Liquid Crystal Display) projectors contain three separate LCD glass panels, one for red, green, and blue components of the image signal being transferred to the projector. As the light passes through the LCD panels, individual pixels can be opened to allow light to pass or closed to block the light. This activity modulates the light and produces the image that is projected onto the screen.
DLP (Digital Light Processing) is the world’s only all-digital display solution. DLP technology uses an optical semiconductor, known as the Digital Micromirror Device, or DMD chip to recreate source material.
Advantages of DLP
Disadvantages of DLP
The ‘rainbow’ effect, appearing as a momentary flash of rainbow-like striping typically trailing the bright objects when looking from one side of the screen to the other, or when looking away from the projected image to an off-screen object. Only some people see this effect, or you can create it for yourself by moving your eyes very quickly across the screen. The old models had four segments on the color wheel, but the new ones have five or more and spin faster, which means less rainbow effect and more saturated color.
A footnote on LCD vs DLP (extracted from projector expert source)
DLP technology is superior to LCD projection in numerous ways. Digital Light Processing technology ensures that every pixel on your projected image gets exactly the same amount of light, there is no fading around the edges of the screen, and colors look sharp. Also, DLP consists of one single chip, instead of three bulky LCD panels, resulting in smaller projectors without any loss of image quality. Reduced pixelation is another benefit of DLP. LCDs were always known for their visible pixel structure, often referred to as the screen door effect because it appears as though the picture is being viewed through a screen door. Inherently, DLP will always give you the better visual image, and retain its image quality over time for an overall lower cost of ownership.
“DLP technology delivers images in a broad range of projection and display applications including business projectors, home entertainment projectors, large screen tabletop TVs, video walls and projection systems used in commercial entertainment. Its digital nature and thermal characteristics mean that its image does not degrade over time, and it does not suffer from the “burn in” that afflicts other technologies and impairs image quality.” – Gary Kayye, Kayye Consulting, Knews: Projection/Display Industry Newsletter.
Additional Advantages of DLP