Ask the Tech
Technology is moving at a breakneck pace. Every day there are new acronyms, new components, new gadgets hailed as “the next best thing.” So you’re bound to have questions about communications technology and how it impacts your business.
Got a question? Browse through some of the recently submitted questions — you might find your answer there. Or use the form below to submit your question. One of our certified technicians will provide an answer within a few days.
How do you determine projector brightness?
The SMPTE (Society of Motion Picture and Television Engineers) recommendation for viewing a movie in a darkened room is 16ft/lamberts. The SMPTE recommendation for a CRT TV in normal ambient light is 50ft/Lamberts to allow for reduction of light output of a projection lamp as it ages.
With these “recommendations” to start with, there are a number of other factors that guide us to choosing the brightness output of a specific projector. Some of these factors are front vs rear projection. ambient light level vs artificial lighting and control, commercial vs residential, screen size, and typical usage of projection system. These are just some of the factors that weigh in on projector selection.
In any case, keep in mind that brighter is not always better. Too much brightness is difficult on the viewer’s eyes and the same is true for too little brightness.
A few rules of thumb (these are not carved in stone just guidelines):
• No ambient light and total control over artificial light and a modest screen size (under 96” wide) a 1000-1200 lumen projector is more than bright enough. This is where contrast ratio is most important.
• Medium level ambient light and control over artificial light with same modest screen size –
2500-3000 lumens is recommended.
• Bright ambient and artificial light – 4500+ lumens is recommended.
How do I determine the proper screen size for a room?
Determining the optimum screen size is based on room dimensions and planned audience seating size and arrangement. The rule of thumb is to fit the screen to the audience – not to the projector.
o Screen height should be approximately equal to 1/6 the distance from the screen to the last row of seats, allowing text to be read and detail to be seen in the projected image. Ideally, the first row of seats should be approximately two screen heights away.
o You want to make sure the audience has a good view so the bottom of the screen should be a minimum of 4 feet above the audience floor. This may require additional screen “drop” for ceiling hung screens.
In addition you have to consider the appropriate format for your projection application based on the type of media you will be displaying. Also you need to consider future formats…especially high definition.
Common formats and aspect ratios are as follows:
NTSC Video 1.33:1
PAL Video 1.33:1
Wide Format 1.60:1
HDTV Video 1.78:1
Letterbox Video 1.85:1
35 MM Filmstrip 1.32:1
2×2 Standard 35MM Double-Frame Slides 1.50:1
Super XGA Computer 1.25:1
Cinemascope 2.35:1
Once you have your calculations and media selected you can contact a dealer to find out the proper image size.
I need to control my sources from a central remote…what are my options?
What’s the difference between mono and stereo audio?
In the most basic of terms Monaural Audio refers to all loudspeakers in a audio system reproducing the same signal content at precisely the same time at the same level.
Stereo audio has some of the audio content separated between the left and right channels. This gives the listener an “imaging” effect that certain sounds are heard more on the left than the right and vise versa.
It is a common misperception that “Mono” audio lacks the sound quality of “Stereo” audio. In fact they both have the same frequency capabilities, the only difference is the separation of content.
Most people do not realize that most all live concerts are “mono”. If concerts were stereo then the people on the left of the stage would hear something different than the people on the right side of the stage. In theory the only people who would hear everything would be the ones located in the middle between the sets of speakers.
We would need more information in order to accurately answer this question. In short, you do have many options in developing a single point of control.
The following issues need to be addressed first:
• What are the sources to be controlled? If this is an existing system we would need to know the manufacturer and model # of all the equipment. If it’s a new system we would conduct a needs analysis and find out the presentation requirements.
• Budget is always a consideration. There are many levels of pricing.
• Remote location is a factor: Does the remote have to be wireless, wired, placed on a table, installed in a wall?
Communitronics can provide many different levels of remote control systems. Contact one of our system specialists for a quote.