The projector calculator takes screen diagonal, height, horizontal lens offset, maximum throw ratio, minimum throw ratio, projector brightness, resolution, screen gain, vertical lens offset and tan and returns horizontal lens center position, vertical lens center position and longest smpte recommendation. It is built for quick answers, for checking somebody else’s arithmetic, and for the moments when a formula book is not within reach.
What Is the Projector Calculator?
The projector calculator turns screen diagonal, height, horizontal lens offset, maximum throw ratio, minimum throw ratio, projector brightness, resolution, screen gain, vertical lens offset and tan into horizontal lens center position, vertical lens center position and longest smpte recommendation.
It is a quick way to get from the numbers you have to the number you need, without setting up a spreadsheet or reaching for a formula.
How the Projector Works
Each result follows from the ones before it, and the calculator shows every step, so a surprising answer can be traced back to the input that caused it.
Round your inputs to the precision you actually know, and keep more precision than that in the intermediate steps.
Getting a Result You Can Trust
Run the calculation twice with slightly different inputs. A sensible calculator moves its output in proportion; a wild change points to a unit or a decimal point problem in what you entered.
Write the inputs down next to the answer. It takes a moment and it is the difference between a number you can explain and one you cannot.
A Worked Example
Working through an example, with screen diagonal set to 10, height set to 5, horizontal lens offset set to 2, the calculator returns width of 8.66025, and maximum of 18.7558, and longest smpte recommendation of 16.1603. Substitute your own figures and the same steps produce the same kind of answer.
Frequently Asked Questions
What do I need to work out horizontal lens center position?
Enter screen diagonal, height, horizontal lens offset, maximum throw ratio, minimum throw ratio, projector brightness, resolution, screen gain, vertical lens offset and tan. The calculator then works through the relationship and reports horizontal lens center position, vertical lens center position and longest smpte recommendation.
What does the projector actually calculate?
It takes screen diagonal, height, horizontal lens offset, maximum throw ratio, minimum throw ratio, projector brightness, resolution, screen gain, vertical lens offset and tan and converts them into horizontal lens center position, vertical lens center position and longest smpte recommendation using the standard relationship for this problem. Each step is applied in turn, so every output is traceable back to the numbers you typed in.
How should I enter screen diagonal?
Use the value you actually have, in the unit shown next to the field. Enter every value in the same unit system. The calculator assumes the figures you supply are consistent, so it cannot correct a mistake that happens before the calculation starts.
Do I have to fill in every field?
Only the fields a particular result depends on. If you leave one blank, the results that need it simply show a note instead of a number, and everything else still works.
Does anything you type get stored?
No. The whole calculation runs inside your browser, and nothing you enter is uploaded, logged or sent anywhere.