Understanding laser projectors and specifications
There are a lot of laser projectors on the market today, and many manufacturers use different terminologies to market and sell laser projectors. The configuration of your laser projector, and the quality of the components used inside, have a direct impact on the type of laser shows and content you can create. Here we will provide some basic guidance about laser specifications, to help you understand what to look for when buying or comparing laser show projectors.
Laser powers and how to interpret them
Lasers come in a wide variety of power levels, and the power of the laser is important to understand when choosing the right laser for your desired application. Laser powers are generally specified in terms of “watts (W)” or “milli-watts (mw)”.
- 1W= 1,000mw
- Take note of this, as it is important when understanding the power of your laser.
You also need to be careful when looking at laser powers to be sure you are getting the actual output power you need. You should also purchase a laser power meter, so that you can accurately measure the real output power of your laser over time.
When you are looking at different laser systems, it is important to know the exact output power of the laser, at the output window. As that is the real amount of power you will have to work with when performing shows. This is also important for various laser safety aspects, if you are performing an audience scanning laser show.
There are some clever “marketing and sales” terminology used out there, that makes certain laser projectors look more powerful than they actually are. So when comparing different lasers, be weary if you see terms like:
- Minimum / Maximum output power – In this case, the maximum laser power is what is produced inside of the laser – It is NOT what you will get in real laser power, at the output window. As every time a laser hits an optic, it has a small loss of power.
- Apparent brightness – This is a generalized term, and it does not mean your laser actually has the power being specified. You might see certain suppliers say their laser has an “apparent brightness of 1W”… THIS DOES NOT MEAN YOU HAVE A ONE WATT LASER. It only means they are claiming that the output power looks like 1W… When it most cases, if you were to put a laser with an apparent brightness of 1W side by side with a real 1W laser, you will surely see a noticeable difference in brightness. So make sure that if your supplier uses the apparent brightness technique for specifying their laser’s power, that you ask them for the real output power of the laser projector, at the output window.
** All laser projectors offered by Pangolin, have their specification for power listed at the output window. So you will get the exact laser power specified – and sometimes even more : )
Choosing the right laser power, for your needs
Deciding what power of laser to get can also be confusing at times, as there are a lot of laser powers available. A basic guide of what power is right for a given application is noted below.
- Low Power Lasers (500mw – 3W) – Well suited for indoor shows, such as small to medium size clubs. Also great for home use.
- Medium Power Lasers (3W+ – 12W) – Well suited for medium to large scale indoor venues, as well as certain types of outdoor laser shows (think small festivals). These are also well suited for graphic projections outdoors, at night.
- High Power Lasers (15W – 40W) – Well suited for large scale indoor venues (think stadium sized shows) as well as large outdoor shows (festivals, stadiums, long distance aerial projection, large outdoor graphics projections, etc.).
Laser colors (and laser modulation)
Most laser projectors have one to three laser modules (red, green, and blue) but the international standard provides for up to 6 color channels to control up to 6 different color laser modules. A laser module’s color is determined by its wavelength which is measured in nanometers (Nm). All 6 international standard colors are noted below.
With that being said, the vast majority of laser show projectors on the market use three color sources (Red, Green and Blue). We call these “RGB” laser projectors. And with RGB based laser projectors, you can create nearly any color in the spectrum.
When working with RGB laser projectors, it is very important to have a system with an even balance of red, green and blue laser sources inside, as this is a critical element that allows you to create a wider variety of colors from the laser projector.
A good ratio of red, green, and blue is about 20-30% red, 30-40% green, and around 40-50% blue. Green is the most visible color for lasers. Blue is also the cheapest laser source. So it is common for some budget manufacturers to advertise high power lasers, but use a lot of blue. This is generally not good, because even though you have more power, you have unbalanced colors. And in reality, an evenly balanced laser with good color combination will appear brighter to the human eye, than even a higher power system with an uneven balance of red, green, and blue. So when comparing brightness, it is not just about “power” … Color balance, quality optics, and internal components, are all equally important.
Analog and TTL modulation
There are two types of modulation when it comes to lasers. These include “analog” and “TTL” based systems. Without getting too technical, if you use an analog laser projector with good linear modulation, you can create millions of different color combinations, and evenly fade in, and fade out between those colors when creating different laser effects.
If you have a TTL based laser, you are limited to only seven colors in total, and you cannot fade in, and fade out across different colors. Generally speaking, budget level lasers or those which are lower in price, are TTL based. While more professional lasers tend to be analog modulated.
Modulation and Blanking
This is an externally caused change in laser power, which turns the laser on and off and also allows for the fading of colors. Blanking, or disabling laser output in a specified area when projecting an image, is commonly used when drawing laser animations to separate image components, so they are not connected by a low power line.
For example, if the word “TEXT” is projected, a properly blanked laser with analog response and a good linear balance would turn off (0% power) between each letter of the word, allowing you to clearly see each letter in the projected image.
Whereas in less professional laser systems, you will see a line or tail going through part of word, as illustrated in the “TEXT” example below.
This is good (analog modulation, linear balance)
This is bad (poor modulation, blanking lines visible)
Understanding optical scanning specifications
Most laser projector manufacturers use the term “KPPS” or kilo points per second, when defining optical scanning speeds. So you might see specifications like “20K, 30K, 40K, 60K, etc., when looking at the optical scanning speed of your laser.
What is just as important as the speed of the optical scanning system, is the angle which it is specified at. All optical scanning specifications inside of laser projectors should be done at 8°.
This is the standard set by the International Laser Display Association, which oversees most laser specifications on the market currently. We use 8°, because this is generally the smallest scan angle you would ever really use in a real world scenario.
So for example, you might see “30K @ 8°” or “40K @ 8°”, etc…
But again, make sure you are closely watching the angle at which the speed is defined, because that is just as important as the KPPS speed being defined. If you see a scan speed specified at less than 8°, or if you do not see any angle specified, be cautious.
- Some people will say “30K @ 4°”… Again in this specific case, you want to be careful. Because 4° is not the correct angle to measure a scan speed at. The ILDA test pattern which is used to measure scan speeds was designed to be measured them at 8°. Therefore when measured properly, a specification such as “30K at 4° does not actually have a “30K” scan speed. With that kind of specification, you cannot expect to have a true “30K” projector, as denoted by the international standard.
Another important thing to consider when looking at optical scanning systems on your laser projector, is the optical degrees it can project at, on an X and Y axis. For example, some people will say +/- 60° optical on the X and Y axis. You want to take note of this, because the angle you can project at directly effects how large of a projection area you can cover with a single laser. Better lasers on the market will start at +/- 60° optical on the X and Y axis.
Here is an overview of optical scanning specifications,
and how they related to the effects you can create…
- 30K @ 8° (+/- 60+° optical on the X and Y axis) – This will be well suited for laser beam effects, and it can also be used for basic laser graphics, text and logo projections. The +/- 60° optical is a pretty large scan angle, and will allow you to cover a relatively wide projection
- 40K @ 8° (+/- 60+° optical on the X and Y axis) – This will be well suited for laser beam effects, and it will also give you sharper looking laser graphics, text, and logo projections.
- 50K @ 8° (+/- 60+° optical on the X and Y axis) – This will be well suited for laser beam effects, and it will also give you very sharp looking laser graphics, text, and logo projections.
- 60K @ 8° (+/- 60+° optical on the X and Y axis) – This will be well suited for nearly any type of laser display you might wish to create. However, there are only a few optical scanning which can really achieve this speed.
Below is a list of quality optical scanning systems you can trust, that have been properly measured to produce accurate scan speed specifications.
- Compact-506 – A high quality and affordably priced optical scanning system, suitable for all types of laser beam effects, as well as good quality laser text, graphics, and logos. These are generally used in lasers ranging from 500mw in power up to around 7watts, due to the size of the mirror they can support.
- ScannerMAX Saturn 1 – A high end optical scanning system that performs beautiful laser beam effects, and exceptionally crisp laser graphics, text and logos. This is currently the fastest optical scanning system in the world. If you need precise laser graphics on a low power to medium power laser projector, this is the best optical scanning system to use. But, it is a bit expensive. If you do not need this precision, the Compact-506 is generally well suited for most standard applications.
- ScannerMAX Saturn 5 – A profesional optical scanning system mainly used in high power lasers. These are well suited if you have a high power laser (12W or more) and you need to project very precise laser graphics, text or logos with it.
- Cambridge CT6215 – This is another good optical scanning system, and commonly used across the laser show industry because it was one of the first optical scanning systems integrated into a laser projectors.
- ScannerMAX Saturn 9 – A high end optical scanning system, that is very well suited for laser beam effects, as well as laser graphics, text and logos. The main benefit of the Saturn 9 is that it can drive a very large mirror, to a relatively fast scan speed. This becomes beneficial in higher power laser projectors, as it will allow you to lower the beam divergence over a longer distance, giving you a brighter and more visibly bright beam profile over long distances.