Frequently Asked Questions

Projector Questions and Answers

In an LCD (liquid-crystal display) projector light from a single lamp is directed to a trio of miniature LCD panels that process the red, green, and blue light components separately. The pixels in each panel contain a liquid-crystal material that regulates the amount of light passing through them by twisting and untwisting in response to electrical voltages. After exiting the LCD panels, the three colored beams are combined by a prism and projected onto the screen by a lens.

Most DLP (Digital Light Processing) projectors have a single chip and a spinning colour wheel that chops white light from a lamp into a sequence of red, green, and blue beams (sometimes yellow and white too). The beams are reflected from the chip that contains hundreds of thousands of tiny mirrors. These mirrors pivot thousands of times a second to control the brightness of the pixels and are synchronized to display a red, green, or blue projection that the eye blends into a full-colour image.

lcd dlp

Ask us just 10 years ago and we would have said there was a big difference in image quality and reliability between the 2 popular technologies, with so many changes occurring over the past decade there is very little difference. We generally recommend not to worry too much about the technology being used, the overall quality and suitability of a projector really comes down to the individual model. There are some great DLP's on the market and some great LCD's too.

As a very generalised rule LCD projectors tend to have more vibrant colour however the pixels are spaced further apart so you can get the 'screen door' effect. This effect is primarily an issue on low resolution projectors, FULL HD and 4K resolution projectors rarely have this problem. DLP Projectors tend to have deep black levels and can have a smoother image too although, due to the way the colour wheel works, a small percentage of users may see the 'Rainbow' effect. This effect basically looks like a rainbow of colours across the screen and is typically visible when you move your eyes across the screen rapidly. This effect is only visible with a very small percentage of the population in varying severity. As with the issues LCD projectors faced in the past, the DLP companies have made improvements to reduce the risk of the Rainbows effect.
As LCD and DLP technology are so similar we recommend to compare the specifications and features and not to worry as much about the technology being used inside the unit, it doesn't matter as much as in the past since both technologies can produce brilliant pictures.

Lamps, LED's, and Laser's are all lightsources that can be found in projectors. Projectors traditionally use a lamp to create the light, these lamps are typically replaced every 4000-20000 hours (depending on the model). Lamp-Less lightsources such as LED's and Lasers usually cannot be replaced but are designed to last longer than a lamp. LED's are widely used in small/mini projectors but can also be used in the odd larger model... they tend to not be as bright as most lamp or laser projectors. The Laser lightsource is mainly used in bright business or large venue projectors. A laser projector is normally more money up front but you can save money in the long term... especially if operating your projector heavily or if the unit is in a difficult to access location making lamp replacements expensive. As the laser light tends to be quite bright it is rare for them to be used in home theatre projectors. For home users a lamp based model is more common.

A Native Resolution is essentially a measurement for the number of pixels (or dots) being projected. The most common measurements for projectors are:
SVGA - 800x600
XGA - 1024x768
WXGA - 1280x800 (HD)
WUXGA - 1920x1080 (FULL HD)
WUXGA - 1920x1200
UHD - 3840 x 2160 (4K)
The WXGA, WUXGA, and UHD resolutions are widescreen, these are what we recommend for now for all uses. The SVGA and XGA resolutions are the old 4:3 ratio (or more square in shape), these resolutions are slowly being phased out. Both WXGA and WUXGA are fine for a typical Powerpoint presentation however for a more detailed image best to stick with a WUXGA/FULLHD projector.
For home theatre there are now 2 main resolutions in use, FULL HD and 4K. FULL HD is perfectly fine for the vast majority of use however 4K is becoming more popular with the increase in 4K movie streaming and 4K channels on PayTV services.

The new buzz word in installation projectors is the short and ultra short throw range. These offer a much closer installation distance while still giving you a large image size. Having a projector closer to the screen avoids shadows of the presenter and stops the presenter from being blinded by the projectors light. The optics involved in making the image larger can make the projector heavier and larger. They can also have stricter limits on the maximum image size they can produce (normally up to 110"). The short throw projectors tend to also be more expensive than a standard throw.

Most Short-Throw projectors would sit 1-2 metres back from the screen (always check the throw distance before purchasing). There are also Ultra Short Throw projectors would usually sit within 50cm of the screen and use a mirror to project straight up onto the screen.

The brightness of the projector (ie how bright the image will be) is rated by ANSI Lumens. The term ANSI simply means the “American National Standards Institute”, who have come up with a recognised standard to measure brightness. Unfortunately, some smaller and no-name brands do not use the ANSI standard so can have some extraordinary ratings so best to stick with the big brands to ensure the specifications you are reading are accurate.

The recommended brightness level varies depending on use and room conditions.

Home theatre projectors tend to range in brightness from 2000 lumens up to about 4000 lumens. Brightness is not always better for home use. The brighter projectors can cause the projected black levels to be less black or wash out your colours. If you have some light control in your room a typical home theatre projector would be suitable, if you plan on using the projector in very bright room you may be best to look at a business or multipurpose type projector instead.

Multi-purpose projectors tend to have brightness levels from 3500-5500 lumens. These are great for business presentations as well as for entertainment use in rooms that cannot be darkened. For a typical conference room a brightness rating around 4000 lumens is typically enough however in a larger hall you should be looking at 5000 lumens or more.

Large Venue projectors are designed for large conference rooms, halls, and churches. These usually start in brightness around 5000 lumens. These units are great for large image sizes (3+metres wide). The larger the image the brighter the projector should be. If you need assistance selecting a unit please contact Just Projectors.

Every projector comes with a number called the 'throw ratio' which can be used to calculate the installation position of the projector. Many projectors will have 2 Throw Ratio's, one for when zoomed in and another for when zoomed out. Using these 2 numbers you can work out the minimum and maximum distance where you need to place your projector in order to display a certain image size.Just projectors includes a throw distance chart on most projector information pages online so you can easily check the suitability for your installation.
Check out our blog to learn more

Many years ago analogue video cables such as Composite, Svideo, BNC, and Component were the standard connections required to connect up your projector or TV. These connections were perfectly fine for the resolutions of the day however as resolutions increase we need to also increase the quality and capability of the cabling to keep up.

HDMI is the modern standard for connect up video devices including projectors. HDMI uses digital signals and is capable of higher resolutions. Almost all modern projectors will feature a HDMI port you can connect your computer, receiver, or player into. If you have invested in a 4K resolution projector you will need to ensure you are using a newer High Speed HDMI cable that is compatible with 4K signals. For long distances it is also wise to use an Active HDMI or Optical HDMI cable to minimise the risk of signal loss.

USB-C is a newer type of USB port that also features the traditional capability of USB but also can transmit high quality and high speed video signals. USB-C is still quite rare on projectors but if your computer features a USB-C port you can simply use a USB-C-to-HDMI cable to connect up your new projector.

Aspect Ratio is the essentially the shape of the image, it is a ratio that represents how wide an image will be vs the height. Older projectors, and some entry level current ones, feature a 4:3 Aspect Ratio. This ratio is ‘more square’ in shape and was quite popular up to the mid-late 2000’s. Modern projectors tend to use a widescreen shape/ratio of 16:9 or 16:10 to match up with the change in ratio of modern computers. Television broadcast and streaming services tend to use the 16:9 ratio so all home theatre grade projectors will also use this 16:9 widescreen ratio. Resolutions such as HD, FULL HD, and 4K are all 16:9 ratio resolutions.

aspect ratio

When you position a projector above the picture and point it down, or below the picture and point it up your image will appear a skewed. The same will happen if you have the projector off to the left or right of the image, the picture will end up having some distortion as per the below images. Almost every projector now features Vertical Keystone Correction. This is a feature in the menu that allows you to manually adjust the image to 'square it up' or remove the distortion. Some projectors even have Automatic Vertical keystone correction that detects the angle in projection and applies the correction automatically.
Horizontal keystone correction is not as common as Vertical however it works in a similar fashion. If the projector has been placed off to the left or right of the image you can use the Horizontal Keystone correction feature to correct the distortion.

Lens Shift is featured on some larger projectors that allows you to move the image up/down/left/right without the need to tilt or angle the projector. Lens shift is an optical adjustment so, unlike keystone correction, there is no loss in resolution or picture quality. Because the projector is not being angled no keystone correction is required. The lens shift function can add a fair bit to the size and weight of a projector so tends to only be included on larger and higher-end home theatre projectors.

keystone correction

A term defining the difference the whitest whites are from the blackest blacks. If the peak white value is significantly different than the peak black value, the signal is said to have high contrast resulting in well-defined shading. The Higher the better. A contrast of 10,000:1 means that the blackest black on the image will be 10,000 times darker than the whitest white.

The contrast ratio is an important specification to look at should you be looking for a home theatre projector or when you wish to project in a darkened room. It is not of much importance for data/business projectors though as the contrast is usually washed out by the ambient light in the room. Contrast ratio does not have an agreed standard of measurement across brands so can be hard to compare. Talk to our staff if you need assistance in comparing any models you are considering.

contrast ratio

Many home theatre grade projectors feature 3D compatibility allowing you to play 3D Bluray films at home. To play a 3D movie you will need

  • A 3D compatible projector
  • A 3D Blu-ray player
  • A 3D Blu-ray film/disk
  • Compatible 3D glasses
3D Home theatre projectors use Active 3D technologies so require the use of powered Active Shutter 3D glasses (unfortunately those cheap ‘passive’ glasses from the Cinema will not work). Not all active glasses are the same too, some brands like Epson use IR or RF 3D, while other brands like Optoma and BenQ use DLP LINK 3D. You will need to ensure you purchase the correct type of glasses for your projector.

3d home theatre

Laser projectors are an exciting new breed of projector that utilise a Laser to create the light rather than a traditional Lamp. Just like with a normal lamp projector they come in both DLP and LCD variants. The laser light tends to be brighter so is primarily used in large venue business projectors however there are also some new home entertainment projectors that use a laser light too.

As with the diagram below they still use a DLP chip or LCD panels. They still shine out through a lens. The major change is the traditional lamp has been replaced by a laser module. LED based projectors perform a similar role but are limited to the amount of brightness they can produce so are mostly used in smaller portable projectors (although there are now some home theatre models using LED's too). Laser projectors’ brightness is still measured in ANSI lumens at the screen so you can compare apples with apples. There is a common myth that a laser projector always equals brighter, but this is not the case. A projector with a higher ANSI lumen rating will be brighter than a projector with a lower ANSI lumen rating.

laser projector

The resounding benefit of a laser projector is the life of the light source. Though lamps have made improvements boasting a 10,000 and even 15,000 hour lamp life, the numbers are only achievable on the darkest economic mode where you lose a lot of projector brightness. In many cases the actual lamp life, if you are using the projector on normal mode, is only up to 5,000 hours. Most Laser projectors offer a 20,000 hour life with some coming out with economic mode settings to extend this to 30,000 hours and beyond. This saves you money on lamps, downtime and, in tricky installations, hiring scaffolds or scissor lifts. Laser projectors tend to use less electricity than a lamp projector plus most are also Mercury free so much better for the environment.

laser projector benefits

YES! Laser projectors emit diffused light, they are not a direct laser. The projected light from a laser projector is no more dangerous than a bright lamp based projector. Just like with a lamp based projector you should always avoid looking into the lens of a projector while it is on.

General Questions and Answers

Yes! We are located in Bayswater Victoria. You are welcome to collect, just make sure you send us an email or give us a call prior. Please note, we don't keep all items in stock at our Bayswater location so on occassions we may need to transfer your item here first.

You bet. All of our deliveries are well packed to reduce the risk of damage, but just for added peace of mind we insure them too! If your new projector arrives with freight damage please let us know immediately so we can arrange a replacement.

Most projectors and small items tend to be delivered to major east coast cities within a couple days. For our friends in Perth and Tassie best to allow about 1 week. Larger items, such as projector screens, will take longer as we must use specialty freight services for these.

Check out our Delivery Page for more information.

Whilst we do not employ installers directly we can often recommend you an installer that operates in your area.

Most local electricians are more than capable of installing a projector and screen, there are also AV installation franchises, such as Jims Antennas, that operate in most major areas.

All of our items come with a full warranty and protections under Australia's Consumer Law. If your item is faulty, or does not do something as advertised, please contact us as soon as possible so we can arrange a remedy. All the items we sell are brand new and factory sealed (unless specified), this does mean we are unable to offer trial or demo models to customers. If you have made a mistake and ordered the wrong product, please do not open it... get in contact with us right away and we will try to help.

Please visit our Returns Page for further information.

Any questions we missed? Send us an email to sales@gmmultimedia.com.au