[vdr] Re: Deinterlacing

[Emil Naepflein <Emil.Naepflein@philosys.de>]

On Sat, 19 Jun 2004 20:32:23 +0200, Guido Fiala <gfiala@s.netic.de>
wrote:

> What exactly is the screendoor effect (sorry for my ignorance)
> - maybe a german term?

No, but you can translate it into "Fliegengittereffekt". You know when
you have a "Fliegengitter" installed you cannot 

> Is it the visibility of the individual pixels even if the color is the same?
> Then it is here invisible at >1.5 screen width.

Is the the image absolutely sharp?
Do you see the black dot in the center of the mirrors when you got to
the screen?
Have you tested this with a 100 % white image?

> The only thing is the noise it makes (36dB) - maybe CRTs are better here but 

Some have also cooling fans but in general the noise is lower. 

> on the  other side i read the mentioned one in this thread has just 750 "peak 
> ANSI lumens"  which sounds quite dark.

I assume it is a 7" projector. Good projectors with 8" or 9" tubes have
1000+ peak lumen. But in general the CRT users are somewhat limited in
screen size. Some use screens with a gain, but this reduces the viewing
angle considerable and causes other problems. The other point is that
CRT users often have a dedicated room with dark walls and ceilings, just
like in a movie theater.

I use the High Contrast Cinema Vision from DaLite:
A smooth, gray, vinyl finish surface for moderate output DLP projectors.
This surface improves the perceived contrast by lowering black levels
while offering moderate gain. It is a flexible unsupported vinyl fabric
and may be folded or rolled. Available on all models offered with the
Cinema Vision surface. Screen surface can be cleaned with mild soap and
water. Flame retardant and mildew resistant.
Viewing Angle: 45°
Gain: 1.1

> But i wonder why they can have such extremely high contrast ratios (beside 
> that the room has to be really dark to make use of them).

Because you can turn the beam off without light spill. LCD panels cannot
shutdown the pixels completly and DLP pannels can turn the mirrors only
a few grad and the light is still reflected a bit because the surface is
not able to absobe all light between the mirrors fully.

> Well - and i assume the price is the most  important factor - not everybody 
> has the money to screw something the price of a decent car to the ceiling and 
> hopefully have a good insurance!

The price is not the problem because you can get refurbished units for a
price in the range 10.000-20.000 EUR. Sometimes you even get got 7"
units for less than 10.000 EUR. 

BTW, the weight I have at the ceiling together with the electric
projector lift is not much less than a CRT projector. There is always a
way to fix high weights at a ceiling. 

http://www.draperinc.com/Lifts_Mounts_Brackets/LCD_lift.htm

A further factor is WAF. ;-) 

My wife was not very interested in having such a big box like a CRT
projector in the the mid of the ceiling of the living room. So may
solution was to move the projector to the back of the room and hide it
in the ceiling.

> > It has absolutely nothing to do with the PJ because I tested everything
> > with standard TVs taking the native RGB signal (of course with proper
> > termination). The noise was to large for me an the S-video was clean.
> 
> BTW - the DVB-S has just a cinch plug - that is a composite signal not 
> S-Video?

All the cards I have are 1.3 or 1.6 versions. They have all the JP1
connector with the S-Video, RGB and S/PDIF signal on the board.

> My PJ autodetects the output of the DVB-S as 680x554 (viewing PAL material) so 
> the resolution is already interpolated once and a view pixels cut away...

That resolution is certainly not correct. I would disable the
auto-detect. 

Emil