50hz

[Sven]

My Projectors (put simply) do not seem to like 75Hz very much, which I am told is a known bug. The content is all 25fps. At the risk of exposing my ingnorance, I am interested to find out why I cannot run a display at 50Hz in Catalyst?

Thanks.

Sven

[samsc]

i cannot switch my displays in the 'Displays' preferences to run at 50hz.

can you?

[Sven]

No.The question is, why can't I?
As it turns out the Barcos I am using prefer multiples of 30Hz, so I am barking up the wrong tree anyway by wanting to change the frequency to 50Hz. Never mind.

[samsc]

monitors tell the computer which resolutions they support.

sometimes.
most of the time, they should.

And then there are the graphics drivers.

Somewhere in the OS some piece of software is deciding that the monitor output cannot be run at 50Hz, this is beyond my control.

--
50Hz refresh on a CRT would flicker terribly.
But on an LCD it might just be acceptable.
--
You can run the TV ( svideo ) output at 50Hz.
But this isnt any good for you as I think you are using a high resolution output 1280x1024?

[samsc]

No.The question is, why can't I?
As it turns out the Barcos I am using prefer multiples of 30Hz, so I am barking up the wrong tree anyway by wanting to change the frequency to 50Hz. Never mind.

Projectors have their own native refresh rate --- which complicates the entire thing.

Sometimes monitors will convert what they receive to a common rate which works with the DLP chips.

Are you using a DLP projector?

(DL1's also dont like working at 75hz - when you strobe them fast (black/white ) - you will notice banding in the image - but for most content this is OK )

[samsc]

If you change to 60Hz/30fps, please note there is a bug in the OS which requires the installation of the ATI displays software, and the manual setting of a 'performance setting'

Please see:

http://chaldee1.gotadsl.co.uk/~richa...read.php?t=448

[samsc]

you cant really switch to 60hz can you?
all your content would speed up?

and you are using hidef stuff, so the performance probably wouldnt be enough?

[tharding]

Which Barco projector are you using?

Another solution is to put a scan converter inline like a Sony 1024 or Extron USP405. with these you should be able to output at whatever frequency you like.

Cheers

Toby

[Mr_P]

Think this 75Hz issue is a BIG problem...

especially as a number of reputable hire companies with lots of DLP's end up having to use them at 75Hz because there's no other option with catalyst...

(unless we all use NTSC footage and switch to 30Hz and multiples therof...)

So whats the solution?

[samsc]

But isnt the issue that the DLP projectors dont like 25 or 50 or 75?

That they work better at 60hz???


----

you dont have to use 'ntsc' footage in catalyst
switching to 30hz, just speeds up the playback.

you dont have to make a single change to the content.
pal content will playback at 30fps thats all that will happen.