I just want to say Hi to all of you. This is a great forum.
Just joined the forum. Been reading for months now and really enjoy the reviews, the comments, the fun, ext, and ext.
But moving on.
For a new guy it's a long posting.
I've been looking into getting either a LT150 (DLP) or VT540 (LCD) for my home theater. I've read great reviews on both.
I understand the screen door effect with the LCD's (don't know if I can live with it though). I've seen the effect from some of your pics you have been posting. But could not find any on the rainbow effect (which would be hard to capture). Also reading some of your post, and it seems know one knows really why these effect happens to some people and not others, why some projectors show more than others, and why hooking them up to HTPC, SD, or Progress DVD show the rainbow effect.
I wanted to under stand why this happens too. I'm one of those who will dig deep to find the answer. So I've been doing some research on the Internet. After searching, I have found some answers to some of the reason why this happens.
These theories are based on what I read and my own conclusions form reading these articles.
One place I found is from ExtremeTech, the article is on Flat Panel Technology but they explain about DLP's. (ExtremeTech article click here)
Short Summery of the article:
DLP use a technique called Field Sequential Illumination. As you know they use for the lower price projectors a color wheel (red, green, blue, and sometimes white to add more light to white and lighter shades of colors in the image). All this happens faster than the human eye can see, and the separate fields are combined in the brain where they are perceived as a single, full-color image. (Since this is done in the brain that is probably why some of you are more prone to it than others.)
Also field-sequential images can appear to break up into different colors if you look from one spot on the screen to another, especially if the image has small white objects on a black background. In projector applications, the motor used to spin the color wheel can be a noisy distraction (vibrations or unbalanced). Which will cause the rainbow effect. (Which some of you agree with that it could be the color wheel.)
Now that explains one reason. The other is on technology. Talking to an engineer explained why your PC, CABLE BOX, or DVD sometimes shows the rainbow effect.
It is do to the A/D Converter (Analog to Digital Converter), which is in the projector. He believes that it might not be a good one or fast enough for the conversion. That is why using Svideo (analog input) does not do well. The reason PC's work great, is that's it uses Digital to Digital no conversion going on, unless your video card is not the latest or greatest technology. And also goes for the same reason that some Progressive Scan DVD players, which are digital to digital, sometime show the rainbow effect. Some technology is better than others.
I hope this helps anyone with the rainbow effect questions on why this happens.
One more thing. Check this article also by ExtremeTech on Color Depth. Which will answer other questions on CRT vs. LCD, and on colors on LCD projectors (this also proteins to DLP since they are based on the same principles) and blacks (for those obsess with blacker than black). (Click here for Color Depth and scroll down to Color Depth.)
For those like DLP here is a neet sight to look at.
www.dlp.com
Note:
These theories are based on what I read and my own conclusions form reading these articles. (I'm new to this site so please take it easy on me if you have any arguments on this matter. Thanks.)
Just joined the forum. Been reading for months now and really enjoy the reviews, the comments, the fun, ext, and ext.
But moving on.
For a new guy it's a long posting.
I've been looking into getting either a LT150 (DLP) or VT540 (LCD) for my home theater. I've read great reviews on both.
I understand the screen door effect with the LCD's (don't know if I can live with it though). I've seen the effect from some of your pics you have been posting. But could not find any on the rainbow effect (which would be hard to capture). Also reading some of your post, and it seems know one knows really why these effect happens to some people and not others, why some projectors show more than others, and why hooking them up to HTPC, SD, or Progress DVD show the rainbow effect.
I wanted to under stand why this happens too. I'm one of those who will dig deep to find the answer. So I've been doing some research on the Internet. After searching, I have found some answers to some of the reason why this happens.
These theories are based on what I read and my own conclusions form reading these articles.
One place I found is from ExtremeTech, the article is on Flat Panel Technology but they explain about DLP's. (ExtremeTech article click here)
Short Summery of the article:
DLP use a technique called Field Sequential Illumination. As you know they use for the lower price projectors a color wheel (red, green, blue, and sometimes white to add more light to white and lighter shades of colors in the image). All this happens faster than the human eye can see, and the separate fields are combined in the brain where they are perceived as a single, full-color image. (Since this is done in the brain that is probably why some of you are more prone to it than others.)
Also field-sequential images can appear to break up into different colors if you look from one spot on the screen to another, especially if the image has small white objects on a black background. In projector applications, the motor used to spin the color wheel can be a noisy distraction (vibrations or unbalanced). Which will cause the rainbow effect. (Which some of you agree with that it could be the color wheel.)
Now that explains one reason. The other is on technology. Talking to an engineer explained why your PC, CABLE BOX, or DVD sometimes shows the rainbow effect.
It is do to the A/D Converter (Analog to Digital Converter), which is in the projector. He believes that it might not be a good one or fast enough for the conversion. That is why using Svideo (analog input) does not do well. The reason PC's work great, is that's it uses Digital to Digital no conversion going on, unless your video card is not the latest or greatest technology. And also goes for the same reason that some Progressive Scan DVD players, which are digital to digital, sometime show the rainbow effect. Some technology is better than others.
I hope this helps anyone with the rainbow effect questions on why this happens.
One more thing. Check this article also by ExtremeTech on Color Depth. Which will answer other questions on CRT vs. LCD, and on colors on LCD projectors (this also proteins to DLP since they are based on the same principles) and blacks (for those obsess with blacker than black). (Click here for Color Depth and scroll down to Color Depth.)
For those like DLP here is a neet sight to look at.
www.dlp.com
Note:
These theories are based on what I read and my own conclusions form reading these articles. (I'm new to this site so please take it easy on me if you have any arguments on this matter. Thanks.)