possible fix for rainbow effect ? htpc refresh rate - AVS Forum
Forum Jump: 
 
Thread Tools
post #1 of 7 Old 04-28-2001, 07:01 PM - Thread Starter
Member
 
safire's Avatar
 
Join Date: Apr 2001
Location: Australia
Posts: 30
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I am one of those people that see the rainbow effect in single dlp projectors. I have heard if you run your pc dvd into the projector and set the refresh rate higher than 60hz, preferably 72hz that the color wheel spins quicker as it synchs to the refresh rate then this rainbow effect would reduce somewhat even perhaps go away to the human eye. I was wondering has anyone tried this and if you would know if most dlp projectors let you run at 72hz or does the projector convert it back to 60hz. I am planning to but the sharp PG-M10x as this would have to be one of the cheapest XGA dlp projectors out there at the moment. I would love to hear from anyone as well if they have heard about this model or have one to advise me if this model is o.k Thanks
safire is offline  
Sponsored Links
Advertisement
 
post #2 of 7 Old 04-29-2001, 02:50 AM
Advanced Member
 
dubmaster's Avatar
 
Join Date: Dec 2000
Location: Florence, Italy - SP7205 - Sharp 37GD1 - 4 HTPCs
Posts: 810
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
It's a good question, i always wondered too.
My experience is that my Proxima DX3 has tearing problems with refresh higher than 60hz.
bye

------------------
dubmaster
dubmaster is offline  
post #3 of 7 Old 04-29-2001, 07:08 AM
Member
 
Robert Payne's Avatar
 
Join Date: Apr 2000
Location: Kingsland, GA
Posts: 62
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I also have a Proxima DX3. When I run it at 60hz, the rainbow effect is so bad that I prefer not to watch the movie. However, when I run it at higher refresh rates (currently at 90hz) the rainbow effect is almost non-existant. I'd say the htpc definately helps in this regard.

Dubmaster: You mention tearing problems with your DX3 at refresh rates greater than 60hz. What software player are you using for watching DVDs? I find myself using WinDVD rather than the ATI player. The ATI player may have a better picture, but for some reason, WinDVD doesn't tear as badly; so, I prefer it.

-robert

------------------
"Of Course I'm at home. I'm un-cool."

"Of Course I'm at home. I'm un-cool."
Robert Payne is offline  
post #4 of 7 Old 04-29-2001, 10:08 PM
AVS Special Member
 
indygreg's Avatar
 
Join Date: Feb 2001
Location: indianapolis
Posts: 1,109
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
i have a compaq 2800 and run at 75hz (the max directly supported by the projector). if i REALLY try hard i can barely see it but i NEVER see it when watching a movie. i had several people over tonight and during the white on black credits of a movie i had everyone trying to see it and noone could. i had people look at a word on the screen then look away quickly or look to another word elsewhere on the screen.

greg

------------------
-------------------------
Why does he shake hands with that guy right after he sexed the alligator

-------------------------
Big Red Cinema Build - In Progress
indygreg is offline  
post #5 of 7 Old 05-01-2001, 05:20 AM - Thread Starter
Member
 
safire's Avatar
 
Join Date: Apr 2001
Location: Australia
Posts: 30
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Indygreg, you mentioned you dont see hardly any rainbow effect when running at 75hz do you see it alot more when going back to 60hz or is it just your projector?
safire is offline  
post #6 of 7 Old 05-02-2001, 04:42 AM
Advanced Member
 
Yves Smolders's Avatar
 
Join Date: Feb 2001
Location: Belgium
Posts: 655
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Tried this theory with my LP340 which is usually connected to a PAL Dvd player, 50hz...

Hooked up PC on the VGA port and chose 75hz on the vga card - everytime I switch between the two I can hear the 'whining noise' - the colorwheel - speed up or slow down.

So yes, rainbow might be less of an issue on higher frequencies.

Ah, and those that hate HTPC's, has anyone ever considered this: Instead of using a PC to control the players etc... Build a custom PC with a capture card and dTV - just use the PC as a deinterlacer, and keep using the DVD player & tuner/video whatever, with their outputs going to the pc. Set the PC up for native resolution out at 75hz and hey presto... If you're handy you can make it boot into dtv automatically - no more keyboard, mouse, etc... just a cheap external scaler ;-)

Yves

------------------
Yves Smolders

Yves
Yves Smolders is offline  
post #7 of 7 Old 05-02-2001, 06:31 AM - Thread Starter
Member
 
safire's Avatar
 
Join Date: Apr 2001
Location: Australia
Posts: 30
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
So did you notice a reduction in the rainbow effect except for the whining noise. ????
Did this higher frequency lead to anyother problems like tearing considering the frame rate has sped up a lot??
Also does anyone know how to calibrate the color wheel in a dlp projector as i have heard they are never EXACTLY aligned perfectly hence a properly adjusted color wheel may NEVER produce any rainbow effect?? who knows...
safire is offline  
Closed Thread Digital Hi-End Projectors - $3,000+ USD MSRP

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off