On Thu, 21 Jun 2007 09:14:41 +0100, Jim Lesurf
wrote:

In article , Arny
Krueger
wrote:
"Jim Lesurf" wrote in message



IIUC The BluRay system differs from both standard DVD and HD-DVD in
locating the information layer much closer to the disc surface. Just
100 microns below the read surface, rather than around 600 for other
discs.

IME the most common kind of scratching that puts an end to the
usefulness of a DVD does not come from the read surface side, but from
the label side.

That may be so. I've not encountered any problems with DVD as yet. In
general, it seems to me to be physically about as robust as CD.

However IIUC with DVD the information layers are roughly half-way though
the disc - i.e. about 500 to 600 microns from either surface. But with
BluRay they are only around 100 microns from the playing surface, and over
a mm from the label surface. Thus I am wary of assuming that BluRay will
behave as DVD in terms of vulnerability to scratches or dirt.

Slainte,

Jim

The Blu Ray layer format is described, a little simply, here

http://www.pctechguide.com/34DVD_Blu-ray_Disc.htm

HD DVD is here

http://www.dvdorchard.com.au/images/Hddvd_details.gif

d
--
Pearce Consulting
http://www.pearce.uk.com

"Don Pearce" wrote in message

On Thu, 21 Jun 2007 09:14:41 +0100, Jim Lesurf
wrote:

In article
, Arny
Krueger
wrote:
"Jim Lesurf" wrote in message



IIUC The BluRay system differs from both standard DVD
and HD-DVD in locating the information layer much
closer to the disc surface. Just 100 microns below the
read surface, rather than around 600 for other discs.

IME the most common kind of scratching that puts an end
to the usefulness of a DVD does not come from the read
surface side, but from the label side.

That may be so. I've not encountered any problems with
DVD as yet. In general, it seems to me to be physically
about as robust as CD.

However IIUC with DVD the information layers are roughly
half-way though the disc - i.e. about 500 to 600 microns
from either surface. But with BluRay they are only
around 100 microns from the playing surface, and over a
mm from the label surface. Thus I am wary of assuming
that BluRay will behave as DVD in terms of vulnerability
to scratches or dirt.

There is a significant difference in the hardness and scratch-resistance of
the two layers of plastic on either side of the information layer. One is
polycarbonate, and the other is dried acrylic lacquer.

The biggest difference in vulnerability to scratches is the size of the
features of the disc that carry the information.

In article , Arny
Krueger
wrote:

On Thu, 21 Jun 2007 09:14:41 +0100, Jim Lesurf
wrote:


However IIUC with DVD the information layers are roughly half-way
though the disc - i.e. about 500 to 600 microns from either surface.
But with BluRay they are only around 100 microns from the playing
surface, and over a mm from the label surface. Thus I am wary of
assuming that BluRay will behave as DVD in terms of vulnerability to
scratches or dirt.

There is a significant difference in the hardness and scratch-resistance
of the two layers of plastic on either side of the information layer.
One is polycarbonate, and the other is dried acrylic lacquer.

That's interesting. Although it won't help much if an optical blockage is
due to dirt on the surface

The biggest difference in vulnerability to scratches is the size of the
features of the disc that carry the information.

I assume the main defence will be the way data is interleaved along the
'track' and made redundant. Thus reducing problems due to isolated marks.

I'll be interested to see how this develops as the discs are in use for a
few years. I will also now wonder if there will be some problems with the
dissimilar material popping apart due to thermal cycling effects, etc. :-)

The main reason I mentioned the above was that the 'shallow' infomation
layer is a feature that distinguishes BluRay from previous discs, so may
make the system different in terms of physical vulnerability. It will also
be interesting to see if there are problems with variations in the
thickness of the layer causing prism effects, etc.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html

On Jun 20, 12:28 am, "Keith G" wrote:

IMO, the HDMI/ordinary DVD beat the HDDVD clip (Italian Job II) hands
down - there was equal sharpness in both images but the HDDVD picture
was much darker with less 'luminosity'. The one Bluray clip (Philips
promo 'Follow The Blue Line') was much better than before, but I think
the clip probably sucks anyway - there was still the 'sandy' appearance
on skin tones and the 'orange peel' effect was still apparent. Pump this
digital photo I took of the screen up to get an idea - eyes, nose and
mouth areas, in particular:

http://www.apah69.dsl.pipex.com/show/Bluray%20Pic.jpg


That looks utterly abysmal. Is it a true representation of how it
looks on the screen, too?

I've been increasingly unimpressed by the hi-def images I've been
seeing too - not dissimilar to how you describe things and the image
you've linked to. So much so, I've given up on the current "state of
the art" and picked up (well, with the help of a couple of other
strapping blokes!) a Toshiba 36" CRT for £125. Whilst far from
perfect, it beats the pants off most of the HD images I've seen in
shop displays and at friends and family. I really had high hopes for
HD too.

wrote in message
oups.com...
On Jun 20, 12:28 am, "Keith G" wrote:

IMO, the HDMI/ordinary DVD beat the HDDVD clip (Italian Job II) hands
down - there was equal sharpness in both images but the HDDVD picture
was much darker with less 'luminosity'. The one Bluray clip (Philips
promo 'Follow The Blue Line') was much better than before, but I think
the clip probably sucks anyway - there was still the 'sandy'
appearance
on skin tones and the 'orange peel' effect was still apparent. Pump
this
digital photo I took of the screen up to get an idea - eyes, nose and
mouth areas, in particular:

http://www.apah69.dsl.pipex.com/show/Bluray%20Pic.jpg


That looks utterly abysmal. Is it a true representation of how it
looks on the screen, too?


Not quite - it's a digital photo of a 'freeze frame' so it hasn't been
done any favours, but I think it clearly shows the origin of the 'sandy'
effect on skintones in the (promotional) clip I saw.



I've been increasingly unimpressed by the hi-def images I've been
seeing too - not dissimilar to how you describe things and the image
you've linked to. So much so, I've given up on the current "state of
the art" and picked up (well, with the help of a couple of other
strapping blokes!) a Toshiba 36" CRT for £125. Whilst far from
perfect, it beats the pants off most of the HD images I've seen in
shop displays and at friends and family. I really had high hopes for
HD too.


Superficial sharpness and extreme contrast might be immediately
impressive (much like the *wow* factor of certain speakers) but they do
not make a really satisfying or realistic image, in my book. I have
never liked the 'digital look' which is deathly compared with a good
'analogue' picture and LCD screens only make it worse, from what I have
seen so far!

I suppose where it comes to the fore is in the depiction of certain
'computer generated' imagery where there is no *natural* look to worry
about...??

On Thu, 5 Jul 2007 01:07:12 +0100, "Keith G"
wrote:


wrote in message
roups.com...
On Jun 20, 12:28 am, "Keith G" wrote:

IMO, the HDMI/ordinary DVD beat the HDDVD clip (Italian Job II) hands
down - there was equal sharpness in both images but the HDDVD picture
was much darker with less 'luminosity'. The one Bluray clip (Philips
promo 'Follow The Blue Line') was much better than before, but I think
the clip probably sucks anyway - there was still the 'sandy'
appearance
on skin tones and the 'orange peel' effect was still apparent. Pump
this
digital photo I took of the screen up to get an idea - eyes, nose and
mouth areas, in particular:

http://www.apah69.dsl.pipex.com/show/Bluray%20Pic.jpg


That looks utterly abysmal. Is it a true representation of how it
looks on the screen, too?


Not quite - it's a digital photo of a 'freeze frame' so it hasn't been
done any favours, but I think it clearly shows the origin of the 'sandy'
effect on skintones in the (promotional) clip I saw.



I've been increasingly unimpressed by the hi-def images I've been
seeing too - not dissimilar to how you describe things and the image
you've linked to. So much so, I've given up on the current "state of
the art" and picked up (well, with the help of a couple of other
strapping blokes!) a Toshiba 36" CRT for £125. Whilst far from
perfect, it beats the pants off most of the HD images I've seen in
shop displays and at friends and family. I really had high hopes for
HD too.

CRTs still beat the crap out of LCD or plasma when it comes to
reproducing colour. The flat screen stuff always looks like the colour
has been laid on afterwards as a sort of molten plasticky layer, with
scant regard for fine tone - a bit like a child's first go at painting
by numbers. CRTs make a vastly better job of this.

d

--
Pearce Consulting
http://www.pearce.uk.com

In article , Don Pearce
writes
On Thu, 5 Jul 2007 01:07:12 +0100, "Keith G"
wrote:


wrote in message
groups.com...
On Jun 20, 12:28 am, "Keith G" wrote:

IMO, the HDMI/ordinary DVD beat the HDDVD clip (Italian Job II) hands
down - there was equal sharpness in both images but the HDDVD picture
was much darker with less 'luminosity'. The one Bluray clip (Philips
promo 'Follow The Blue Line') was much better than before, but I think
the clip probably sucks anyway - there was still the 'sandy'
appearance
on skin tones and the 'orange peel' effect was still apparent. Pump
this
digital photo I took of the screen up to get an idea - eyes, nose and
mouth areas, in particular:

http://www.apah69.dsl.pipex.com/show/Bluray%20Pic.jpg


That looks utterly abysmal. Is it a true representation of how it
looks on the screen, too?


Not quite - it's a digital photo of a 'freeze frame' so it hasn't been
done any favours, but I think it clearly shows the origin of the 'sandy'
effect on skintones in the (promotional) clip I saw.



I've been increasingly unimpressed by the hi-def images I've been
seeing too - not dissimilar to how you describe things and the image
you've linked to. So much so, I've given up on the current "state of
the art" and picked up (well, with the help of a couple of other
strapping blokes!) a Toshiba 36" CRT for £125. Whilst far from
perfect, it beats the pants off most of the HD images I've seen in
shop displays and at friends and family. I really had high hopes for
HD too.

CRTs still beat the crap out of LCD or plasma when it comes to
reproducing colour. The flat screen stuff always looks like the colour
has been laid on afterwards as a sort of molten plasticky layer, with
scant regard for fine tone - a bit like a child's first go at painting
by numbers. CRTs make a vastly better job of this.


I haven't seen anything in the shops as yet that is as good as our 10
year old B&O running off analogue PAL despite its limitations especially
compared to anything Digital SD available to Joe pubic;!....
d


--
Tony Sayer

In article , Don Pearce
wrote:
On Thu, 5 Jul 2007 01:07:12 +0100, "Keith G"
wrote:


CRTs still beat the crap out of LCD or plasma when it comes to
reproducing colour. The flat screen stuff always looks like the colour
has been laid on afterwards as a sort of molten plasticky layer, with
scant regard for fine tone - a bit like a child's first go at painting
by numbers. CRTs make a vastly better job of this.

They also avoid the 'crinkly' effect of the display pixels being obviously
visible as a set of rectangles. Personally, I find this very uncomfortable
to view. I've also continued with a CRT monitor on my computer as a result
of finding this effect hurts my eyes.

Difficult to say more about the displays since whenever I go into a shop
that has them, they seem to be set up with the contrast, brightness, and
colour wound up to max, regardless of display type. The result is uniformly
dreadful.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html

"Don Pearce" wrote in message
...
On Thu, 5 Jul 2007 01:07:12 +0100, "Keith G"
wrote:



Not quite - it's a digital photo of a 'freeze frame' so it hasn't been
done any favours, but I think it clearly shows the origin of the
'sandy'
effect on skintones in the (promotional) clip I saw.




But not this bit:


I've been increasingly unimpressed by the hi-def images I've been
seeing too - not dissimilar to how you describe things and the image
you've linked to. So much so, I've given up on the current "state of
the art" and picked up (well, with the help of a couple of other
strapping blokes!) a Toshiba 36" CRT for £125. Whilst far from
perfect, it beats the pants off most of the HD images I've seen in
shop displays and at friends and family. I really had high hopes for
HD too.

CRTs still beat the crap out of LCD or plasma when it comes to
reproducing colour. The flat screen stuff always looks like the colour
has been laid on afterwards as a sort of molten plasticky layer, with
scant regard for fine tone - a bit like a child's first go at painting
by numbers. CRTs make a vastly better job of this.



I don't even like 'flat screens' on small tellies - they look *pushed
in* to me....

On Thu, 05 Jul 2007 09:03:09 +0100, Jim Lesurf
wrote:

In article , Don Pearce
wrote:
On Thu, 5 Jul 2007 01:07:12 +0100, "Keith G"
wrote:


CRTs still beat the crap out of LCD or plasma when it comes to
reproducing colour. The flat screen stuff always looks like the colour
has been laid on afterwards as a sort of molten plasticky layer, with
scant regard for fine tone - a bit like a child's first go at painting
by numbers. CRTs make a vastly better job of this.

They also avoid the 'crinkly' effect of the display pixels being obviously
visible as a set of rectangles. Personally, I find this very uncomfortable
to view. I've also continued with a CRT monitor on my computer as a result
of finding this effect hurts my eyes.

Difficult to say more about the displays since whenever I go into a shop
that has them, they seem to be set up with the contrast, brightness, and
colour wound up to max, regardless of display type. The result is uniformly
dreadful.


That used to be the condition of most domestic TVs when the colour,
brightness and contrast controls were available as a set of knobs on
the front panel.

It still amazes me in shops when you see an array of LCD and plasma
TVs just what a vast range of colour balances there is. They almost
look like they are showing different scenes. I don't know what
standards the manufacturers are using when setting up, but they are
obviously all different. Interestingly Sony have maintained their
insistence that the world is purple - a hangover from their CRT days.

d

--
Pearce Consulting
http://www.pearce.uk.com