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Need more info, but I would suggest a camera aimed at a white target screen illuminated by the light source. Adjusting contrast, brightness and LCD shutter controls would show the brighter areas in the overall light distribution.
The basic idea is, I'll be using, let say a torch light, directed at the white screen, light will be distributed all across. Then, I gotta build some sort of device, photometer? photodetector? to measure the intensity of light at, let say at 2cm interval, along the distributed light. Got what I mean? So first, I need to construct a circuit for measuring the intensity, and to display them. Secondly, I suppose I'll be needing a program. Third, I need to make it move in a straight line, along the light distribution, someone suggested that I get a stepper motor. I need major help as this project is due in 2-3 weeks time..
Yea, that's why I'm focusing on the measurement device at the moment. Any idea how to build the device? A simple circuit to measure and display the intensity of light, as for the moving part, that can be done later on.
??? The device would be the camera. You wouldn't build it, you would buy it. There would be no moving parts.
What you are describing is a mechanical camera to look at a point of light reflected off a white screen, haul the image sensor around with a couple of stepper motors - I wouldn't suggest building one of those.
Hi brenda. We do it all the time in the solar industry. A silicon photocell (solar cell) will output a current with light intensity.
Put the cell in grid position 1, take a current reading from a multimeter (small cells generate milliamps), and move to grid position 2, and repeat. You end up with a map of intensity over the area of interest.
Most any silicon solar cell will work, even those from Radio Shack!
John
??? The device would be the camera. You wouldn't build it, you would buy it. There would be no moving parts.
What you are describing is a mechanical camera to look at a point of light reflected off a white screen, haul the image sensor around with a couple of stepper motors - I wouldn't suggest building one of those.
I don't think they get it Duffy. As for the camera, is there going to be enough dynamic range and how would you lock the "agc" (the shutter controls and post-processing) so that they aren't varying on their own? Is that easy in most cameras? And can you control those from a PC?
Duffy: I don't get it. Camera to do the job? How would the cameras gonna display the light intensity and such? I'm not too concern with the mechanical part at the moment, all I gotta do is constuct the thing first. To get it, that's gonna work. I'm so gonna be screwed. I gotta build it..
As for the camera, is there going to be enough dynamic range and how would you lock the "agc" (the shutter controls and post-processing) so that they aren't varying on their own? Is that easy in most cameras? And can you control those from a PC?
Yes. There's actually a HUGE dynamic range in a plain old CCD camera, but you have to adjust "exposure time", gamma, contrast, and brightness to see just how much range it really has. Yes, you can shut off the AGC. The gamma corrects for linearity of the brightness curve, exposure time helps set overall range for brightness and contrast.
As brenda stated,
"measure the intensity of light at, let say at 2cm interval"
You don't need pixel resolution here.
Draw a 1 inch grid on the wall, and place a photocell at each grid square, and record the currents. Now you have a map of the intensities.
brenda, tell us what you're looking for again, please.
John
Ok, so camera can do the work. By camera, do you mean, those digital camera that we're using? I'm trying to build a device to measure the intensity of light, kinda like a photometer. The motoring part is not important, like I said, that can be done later on. I need to submit the schematic diagram for this device, the measuring device asap. I've no idea how to build it. What I have in mind is something like this, photodiode, connected to an amp to amplified the light intensity, plus some other component, I need to measure the current or voltage, related to the intensity and display them. Will need to write a program to convert the current measured to intensity. Get me?
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