What makes commercial units so much brighter.... is it there optics.... there LCD (is it more transmissive)... there light source..? Although our lights seem pretty bright. Also when people retrofit there projectors with different bulbs do they become a lot dimmer? I Just don't understand what these little 8 pound boxes have over the DIY ones.
Anyone have any answers to help me better understand this... I dont want to start a war comparing DIY to Commercial.... I just want to know what makes a commercial unit so much brighter.
Anyone have any answers to help me better understand this... I dont want to start a war comparing DIY to Commercial.... I just want to know what makes a commercial unit so much brighter.
Comercial LCD based Projectors typically have three monochrome lcds and use a use a beam splitter to split the light source into three different color ranges which is later recombined. This allows much more light through.
DLP has something like 70 percent reflectancy, and is also monochrome and relies on a spinning color wheel to create different colors.
DLP has something like 70 percent reflectancy, and is also monochrome and relies on a spinning color wheel to create different colors.
yep, which results in some people seeing so called rainbow effects, in which the wheel doesn't spin fast enough to transfer the colors.
some people can see it, some can't, their wheels are getting faster and faster though
some people can see it, some can't, their wheels are getting faster and faster though
Well i do know that they have a way higher price, and thats the reason that im trying DIY 😛 Im just a poor student eh 😉
They don't use soup bowls for their reflectors. They have a specially designed and manufactured lighting engine. They also have bulbs with smaller arc lengths. Their LCDs are designed with a higher transparency than computer LCDs. Their optics are also designed specifically for THAT LCD and bulb.
The color wheel / DLP also has something to do with it. If you could find a monochrome LCD (one that only has 1 subpixel per pixel; as opposed to 3 subpixels per pixel with color LCDs) and sync it to a color wheel, that would save you ENORMOUS amounts of room. Why you ask?
Well, with a 15" 1024x768 LCD, you actually have 3096x2304 subpixels (3 per pixel; red, green, and blue). A 15" LCD is 12" x 9". In a monochrome LCD, there is only 1 subpixel per pixel so you would have 1024x768 subpixels (and pixels)! That's 1/9th the size! So instead of a 12" x 9" LCD, you have a 4" x 3" LCD that does the same resolution, 1024x768! Neat huh? So how to get color?
Color comes from the color wheel. Literally it's a circle with a red, a green, and a blue transparency. Imagine a pie chart that's 1/3 red, 1/3 green 1/3 blue. Looks like that. Color can be broken down into "monochrome components". A red component, blue component, green component. So here is the timing issue. When the monochrone LCD displays the "red component" (it's a weird concept because the LCD is still monochrone looking), the red transparency on the color wheel needs to be in front of the LCD. When the "green component" is displayed on the LCD, color has spun so the green transparency is in front of the LCD and the same for the blue. This happens multiple times per frame (which means the LCD has to have a high refresh rate). The combination of red, green, and blue gives you color on the screen. DLP does the same thing as an LCD except it reflects the light instead of light passing through it.
There are other ways to do it. You can split the light into its color components (using a prism). Then you have 3 colors going to 3 LCDs or 3 DLPs.
The color wheel / DLP also has something to do with it. If you could find a monochrome LCD (one that only has 1 subpixel per pixel; as opposed to 3 subpixels per pixel with color LCDs) and sync it to a color wheel, that would save you ENORMOUS amounts of room. Why you ask?
Well, with a 15" 1024x768 LCD, you actually have 3096x2304 subpixels (3 per pixel; red, green, and blue). A 15" LCD is 12" x 9". In a monochrome LCD, there is only 1 subpixel per pixel so you would have 1024x768 subpixels (and pixels)! That's 1/9th the size! So instead of a 12" x 9" LCD, you have a 4" x 3" LCD that does the same resolution, 1024x768! Neat huh? So how to get color?
Color comes from the color wheel. Literally it's a circle with a red, a green, and a blue transparency. Imagine a pie chart that's 1/3 red, 1/3 green 1/3 blue. Looks like that. Color can be broken down into "monochrome components". A red component, blue component, green component. So here is the timing issue. When the monochrone LCD displays the "red component" (it's a weird concept because the LCD is still monochrone looking), the red transparency on the color wheel needs to be in front of the LCD. When the "green component" is displayed on the LCD, color has spun so the green transparency is in front of the LCD and the same for the blue. This happens multiple times per frame (which means the LCD has to have a high refresh rate). The combination of red, green, and blue gives you color on the screen. DLP does the same thing as an LCD except it reflects the light instead of light passing through it.
There are other ways to do it. You can split the light into its color components (using a prism). Then you have 3 colors going to 3 LCDs or 3 DLPs.
after searching online i noticed that metal halide bulbs that are rated at 1200watts are readily avalible and advertised to have initial lumen output at around 120,000 lumens..... my bulb is a 400w MH400U that puts out about 36,000 lumens. SO i figure I'm getting about 250 lumens max out of my projector. Would this bulb bring my projector near the 1000 lumen mark? makeing it easily viewable in the day?.... would black still appear black? or grey due to All of the light?
How many lumens to commercial projector lamps output initialy.... in gerneral
How many lumens to commercial projector lamps output initialy.... in gerneral
Most commercial projectors when they are properly calibrated for the best color/contrast/etc are putting out between 300-400 lumens in a light controlled room.
hailrazer said:
The only reasonable comparison is for a total lumen output, not for something "calibrated". How do you "calibrate" projection of a white screen? You can only calibrate for a specific image, and this calibration is done at the expense of light output. More total light output - better possibility to calibrate. And the truth is that total lm output from our DIY projectors is below 200lm. Not much left to "calibrate" for a nice picture. We can only "calibrate" to get as much brightness as possible, accepting serious degradation to image quality.
Regards
pepe303 said:
I was not talking about calibrating a white screen, that much is obvious.
🙂
When calibrating a commercial projector professionally, they adjust the color contrast , etc AND they adjust the lumen output to get the best desired results. Then after that the meazured lumen output in a light controlled environment is around 300-500 lumens. ANything higher and the contrast and color is washed out.
But thats just what I've been reading in forums about commercial projectors. Feel free to believe what you want Pepe.
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