ok..got some coin for xmas..

[YourGrandpa]

Here's the unit I bought a couple of years ago.

http://www3.shopping.com/xPF-Mitsubishi_WS_65613

[Doombrain]

what's the minimum contrast ratio i should consider?

I can't believe I’m helping you. Something I had to knock up.

Contrast Ratios – A brief description
What is the Contrast Ratio?
The contrast ratio is quite simply a ratio between the brightness of the darkest and lightest tones that the projector is capable of producing. For instance with a contrast ratio of 800:1, if the darkest area was labelled 1 unit of light then the brightest area will be 800 times brighter or 800 units of light.

How come there is such a great range between projector models?
The range between contrast ratios is not as great as the number will at first suggest. This is due to how the eye views brightness. However an 800:1 contrast ratio will be noticeably better than the 400:1 contrast ratio.

How does this work then?
The eye does not respond to light in a linear fashion, it can view a range of brightness. If you walk into a shaded room after being out in the sun then the room will appear dark until your eyes get used to it. Then walk out into the sunshine and you will be momentarily blinded. You will see both brightness ranges well and the contrast in similarly lit scenes will be preserved.

This is because the eye will see a difference between 200 lumens and 400 lumens as the same as the difference between 400 lumens and 800 lumens, it just needs to adjust (like walking outside). The eye sees the following range of brightness as equal steps:



Look at the numbers; these represent the brightness in units of light for each segment.
This represents a contrast ratio of 1:1024. (If the range was from 2 units to 1024 units then the contrast range would be 1:512 even though you have only reduced the total by 1 unit!).

If you increased the scale by one segment that measured 2048 units (double the value) of brightness then you would only increase the range by one shade (there would be one more box on the end brighter than the 1024 box), you would not fit the scale in twice. By doubling the Contrast Ratio you do not double the range.

If we then consider contrast ratios (the ratio in brightness between the lightest and darkest tones) then the difference between 400:1 and 800:1 is just one extra shade or equal step, not twice the range.


What difference does it make to the user?
Contrast and brightness are related, to achieve maximum brightness contrast will be affected. To achieve maximum contrast you need to lower the brightness.

Home Cinema Projectors are used in controlled environments, generally a darkened room, so a high light output is not always required or welcomed. These units are designed with adjustments to allow the user to achieve maximum image quality, these adjustments allow considerable control of the contrast (Home Cinema Projectors include filters in the light path and often a lens iris incorporated in the design to achieve this).

Generally computer displays are generated to display on low contrast devices so in the portable/small office market where price is a consideration preference is given to achieving a level of brightness that will allow the projector to be used in the normal office environment (a well lit room). There is little loss in contrast when using a computer as a source (PowerPoint presentations for example), and by using the pre-set colour modes on Projectors you can easily obtain maximum performance.

So the importance of contrast ratio to the user varies depending on what purpose the projector will be used for. For Business projectors, high contrast ratios are often not as important as brightness (ANSI lumens). For Home Cinema projectors, contrast ratio is more important due to the variety and quality of the images being projected.

It is possible to achieve high contrast and brightness in the same unit but the bulb output level and the level of cooling and control needed obviously affects unit price.

Techy Bit
Brightness is a logarithmic scale and not a linear one, so as you move up the scale the rate of change is not constant (as in a straight line graph) but increases by an exponential value. Although there will be a noticeable difference between a 800:1 and 1600:1 contrast ratios the 1600:1 contrast ratio will not display twice the range of the 800:1 unit.

From the scale above you will notice that the middle shade of grey that you see does not represent a brightness of 50% of the total number of brightness units. In fact it is nowhere near this. Middle Grey on the scale is around the 128 unit mark, with the 1 unit being the threshold or the lowest detectable change in brightness (the device can display) that the eye can detect

Middle Grey is generally accepted to be 18% reflectance; it reflects only 18% of the light that falls upon it. For an LCD panel an individual element would need an opacity of 18%, which equates to a density of 82% to display Middle Grey on the screen. So the top half of the brightness scale that a device outputs (from Middle Grey to White) represents the top 82% of the light output of a device, and the lower shades are less than 18% of the light output of a device.

From this you can see why computer screens are designed to be bright, i.e. they produce the contrast by colour and not shade. As a test look around your screen when the scale is displayed. How many shades are darker than the 128 step and what percentage of the screen area do these represent? You will also be able to see how video differs considerably in its requirements.

There are always the same number of shades between Black and White. In the case of a projector it is finite and depends on the colour depth that the LCD panels are able to display. 24 bit colour will allow 256 different levels of light to pass through the panel and 48 bit colour allows 65,536 different levels. This is entirely different and independent of the contrast ratio.

Should give you a better idea, tonto.

[hate]

i didn't read any of that

[ek]

[Massive Quasars]

He's putting his printer skills to good use.

[farad]

...fuck a tv...buy your moderator spot in R&R...raw can be bought for 7k...

[plained]

there is a moving part in dlp

jus saying is all

[primaltheory]

I have a 60inch sony wega lcd, and its great, I only had one (ONE out of like...1920x1???) picture is great, my pc looks good on it (need a better card if i wanna play q4 on it though), especially hd, the colors just jump out at ya

[hate]

i hooked a 42' plasma

internet works on it..but when i startup a game it goes black..meaning it loads up fine but the screen goes black like a setting is too high...i can hear the music in the game as well as mouse movements

but no lookie lookie

i fucked with max refresh rates in game/desktop settings too

any ideas...?


printer techs need not reply..

[plained]

just for shits n giggls put your comp screen res to 640 x 480

[hate]

i don't fuck around..

[plained]

oh

[hate]

just for shits n giggls put your comp screen res to 640 x 480

it is...but i'm showing 2 displays under settings...but can't delete the second...? the second disply is running 800x600..

[shaft]

How is it attached to your PC?

[hate]

vga cable from geforce 6800 to plasma'pc' input

[hate]

got it

was a conflict

[Dave]

No way I'd buy a digital TV now

[shaft]

got it

pure genius

[+JuggerNaut+]

No way I'd buy a digital TV now

do tell.

[Dave]

you can't make me, bunghole

[+JuggerNaut+]

do it anyway, queerbait.

[hate]

my eyes burn

[+JuggerNaut+]

fix your brightness/contrast settings. for reals though, you should at least use a dvd with the THX optimizer on it and set up your set. eyeballing it's not proper without a reference.