On Tue, 13 Jan 2004 00:20:07 +0000
Glenn Booth wrote:

I'll put it another way... I can see colours that no CRT monitor can
reproduce, and I can display colours on my Eizo F980 that no colour
offset litho device can accurately reproduce.

Of course theres no real reason why either class of device should be
*incapable* of this - its just not within the bounds of *current*
technology... (of course, this presupposes a good 'white' light source
for the transmissive case)

RGB and CMY are merely different views on the same colourspace.

Not when one is transmissive and the other reflective.

By *definition* one of those is transmissve and the other reflective.
otherwise you'd end up seeing an inverse image.

just because neither technology is perfect doesnt change that. You just
have two *limited* views on that colourspace.

It matters not one jot that a value in RGB can be recalculated as a
value in CMY if you can't physically realise it.

In practice, of course, I agree wioth you.

Well, I am limiting my CMY values to those can be printed, yes. Find
me a printer that can give me a true black with no K, and I'll be
impressed (and probably shocked at the cost).

If I had one that could do that I'd be keeping it ;-)

The same goes for a CRT
that can reproduce the 'white' of an equitorial summer sun.

Give it time ;-)

I have to ask, why would they? If you can calculate and output the
correct voltage in the DAC on the fly at the required speed, why would

its far quicker to reprogram 3 256 byte (or 1024) LUTs than to
recalculate and redisplay an entire screenfull of output.

you need LUTs? It's only a voltage varying with time, after all. It
doesn't become a 'colour' until the electrons excite the phosphors. I
can't really see the advantage of doing a memory access to get a
voltage value every time when a good DAC can do it so fast, and so
accurately.

I dont know of any systems that store the LUT in the card RAM. AFAIK its built into the chip.

can only program them with gamma values? are then not in fact
directly addressable ?

It's an ASIC. If you have the right software, you can program them
with anything you like if you format it properly. However, their
intent is to allow hardware acceleration of gamma calculations

Thats something different again...

I guess you may hae noticed this is an area I've had more than a
passing interest in ;-) (I was on the verge of completely re-writing
the linux voodoo3 drivers at one point but other commitments sunk
that project sadly...)

I have to ask... why would you be so concerned about colour accuracy
on a chip that could only output 16 bit 3D colour and had a fairly
shabby DAC?

I always quite liked the VD3. the DAC may not have been stunning, but the accelleration was great (at the time) and the output was razor sharp (easily the most jitter free images I have seen either now or back then, including matrox cards. (the matrox did have better colour output, but jittered more).


--
Spyros lair: http://www.mnementh.co.uk/ |||| Maintainer: arm26 linux

Do not meddle in the affairs of Dragons, for you are tasty and good with
ketchup.

On Tue, 13 Jan 2004 00:20:07 +0000
Glenn Booth wrote:

I'll put it another way... I can see colours that no CRT monitor can
reproduce, and I can display colours on my Eizo F980 that no colour
offset litho device can accurately reproduce.

Of course theres no real reason why either class of device should be
*incapable* of this - its just not within the bounds of *current*
technology... (of course, this presupposes a good 'white' light source
for the transmissive case)

RGB and CMY are merely different views on the same colourspace.

Not when one is transmissive and the other reflective.

By *definition* one of those is transmissve and the other reflective.
otherwise you'd end up seeing an inverse image.

just because neither technology is perfect doesnt change that. You just
have two *limited* views on that colourspace.

It matters not one jot that a value in RGB can be recalculated as a
value in CMY if you can't physically realise it.

In practice, of course, I agree wioth you.

Well, I am limiting my CMY values to those can be printed, yes. Find
me a printer that can give me a true black with no K, and I'll be
impressed (and probably shocked at the cost).

If I had one that could do that I'd be keeping it ;-)

The same goes for a CRT
that can reproduce the 'white' of an equitorial summer sun.

Give it time ;-)

I have to ask, why would they? If you can calculate and output the
correct voltage in the DAC on the fly at the required speed, why would

its far quicker to reprogram 3 256 byte (or 1024) LUTs than to
recalculate and redisplay an entire screenfull of output.

you need LUTs? It's only a voltage varying with time, after all. It
doesn't become a 'colour' until the electrons excite the phosphors. I
can't really see the advantage of doing a memory access to get a
voltage value every time when a good DAC can do it so fast, and so
accurately.

I dont know of any systems that store the LUT in the card RAM. AFAIK its built into the chip.

can only program them with gamma values? are then not in fact
directly addressable ?

It's an ASIC. If you have the right software, you can program them
with anything you like if you format it properly. However, their
intent is to allow hardware acceleration of gamma calculations

Thats something different again...

I guess you may hae noticed this is an area I've had more than a
passing interest in ;-) (I was on the verge of completely re-writing
the linux voodoo3 drivers at one point but other commitments sunk
that project sadly...)

I have to ask... why would you be so concerned about colour accuracy
on a chip that could only output 16 bit 3D colour and had a fairly
shabby DAC?

I always quite liked the VD3. the DAC may not have been stunning, but the accelleration was great (at the time) and the output was razor sharp (easily the most jitter free images I have seen either now or back then, including matrox cards. (the matrox did have better colour output, but jittered more).


--
Spyros lair: http://www.mnementh.co.uk/ |||| Maintainer: arm26 linux

Do not meddle in the affairs of Dragons, for you are tasty and good with
ketchup.

On Tue, 13 Jan 2004 01:47:21 -0000
Jim H wrote:


Icidently, I agree completely that there are colours outside of rgb or
cmyk,
I worked for a while doing proofs for a company that makes foil lids, and
there were plenty of 'extra' colours (luminesents spring to mind)

Now that I'll agree with - but are they really 'colours' as such?

--
Spyros lair: http://www.mnementh.co.uk/ |||| Maintainer: arm26 linux

Do not meddle in the affairs of Dragons, for you are tasty and good with ketchup.

On Tue, 13 Jan 2004 01:47:21 -0000
Jim H wrote:


Icidently, I agree completely that there are colours outside of rgb or
cmyk,
I worked for a while doing proofs for a company that makes foil lids, and
there were plenty of 'extra' colours (luminesents spring to mind)

Now that I'll agree with - but are they really 'colours' as such?

--
Spyros lair: http://www.mnementh.co.uk/ |||| Maintainer: arm26 linux

Do not meddle in the affairs of Dragons, for you are tasty and good with ketchup.

On Tue, 13 Jan 2004 07:30:29 +0000 (UTC)
(Stewart Pinkerton) wrote:

Ian, I can swap between a decent Technics mosfet/bipolar power amp
(SE-A2000) and a pair of Dynaco Mk IIIs leaving everything else common
(record, deck, cart, phono stage, pre-amp, speakers, cables, interconnects )
and a blind man could hear the difference whether you match voltages SPLs or
whatever. Trust me....

Is anyone arguing this point?

I think it was obvious enough that no-one felt the need to :-)


--
Spyros lair: http://www.mnementh.co.uk/ |||| Maintainer: arm26 linux

Do not meddle in the affairs of Dragons, for you are tasty and good with ketchup.

On Tue, 13 Jan 2004 07:30:29 +0000 (UTC)
(Stewart Pinkerton) wrote:

Ian, I can swap between a decent Technics mosfet/bipolar power amp
(SE-A2000) and a pair of Dynaco Mk IIIs leaving everything else common
(record, deck, cart, phono stage, pre-amp, speakers, cables, interconnects )
and a blind man could hear the difference whether you match voltages SPLs or
whatever. Trust me....

Is anyone arguing this point?

I think it was obvious enough that no-one felt the need to :-)


--
Spyros lair: http://www.mnementh.co.uk/ |||| Maintainer: arm26 linux

Do not meddle in the affairs of Dragons, for you are tasty and good with ketchup.

In article , Keith G
wrote:

"Jim Lesurf" wrote in message
...


OK, but very often has other 'effects' like killing the imaging,
timbre and detail as well as trapping the sound firmly in the same
plane as the speakers.....

Well, I listen using a varity of SS designs of amplifier, and have
tried various sorts over the years. I must admit I have not noticed
any correlation between using them and the 'effects' you describe.


Fair enough, but I'm sure you're the first person to admit the
possibility of someone else noticing them.

Accepted. :-)

Were it not for the following I would put it down to a quirk peculiar to
me:

It's not subtle with me - it's glaringly obvious. The difference between
SS and Valve amps is profound - I notice instantly and always.

I have also noticed audible differences between valve amps and SS amps in
the past. Like youself, on occasion I have found these very obvious.
Although in other cases they have seemed small or unnoticable.

However to me this seems quite different to agreeing that SS amps 'kill'
the imaging, etc. This is certainly not my general experience.

Even then, I still might think it's a uniquely personal thing if I
didn't keep seeing phrases like 'holographic imaging' and '3D' in the
comix when referring to valve amplification. (Yes, yes, I know.......!!)

Sign of wisdom to know that what they say in the mags isn't very reliable..

:-)

Like I said before ( a number of times now) - it's no biggie, you either
*get* valves or you don't....

I have certainly heard music on systems that used valve amps and found the
results thoroughly enjoyable.

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
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

In article , Keith G
wrote:

"Jim Lesurf" wrote in message
...


OK, but very often has other 'effects' like killing the imaging,
timbre and detail as well as trapping the sound firmly in the same
plane as the speakers.....

Well, I listen using a varity of SS designs of amplifier, and have
tried various sorts over the years. I must admit I have not noticed
any correlation between using them and the 'effects' you describe.


Fair enough, but I'm sure you're the first person to admit the
possibility of someone else noticing them.

Accepted. :-)

Were it not for the following I would put it down to a quirk peculiar to
me:

It's not subtle with me - it's glaringly obvious. The difference between
SS and Valve amps is profound - I notice instantly and always.

I have also noticed audible differences between valve amps and SS amps in
the past. Like youself, on occasion I have found these very obvious.
Although in other cases they have seemed small or unnoticable.

However to me this seems quite different to agreeing that SS amps 'kill'
the imaging, etc. This is certainly not my general experience.

Even then, I still might think it's a uniquely personal thing if I
didn't keep seeing phrases like 'holographic imaging' and '3D' in the
comix when referring to valve amplification. (Yes, yes, I know.......!!)

Sign of wisdom to know that what they say in the mags isn't very reliable..

:-)

Like I said before ( a number of times now) - it's no biggie, you either
*get* valves or you don't....

I have certainly heard music on systems that used valve amps and found the
results thoroughly enjoyable.

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
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

On Tue, 13 Jan 2004 09:35:59 +0000, Ian Molton wrote:

On Tue, 13 Jan 2004 01:47:21 -0000
Jim H wrote:


Icidently, I agree completely that there are colours outside of rgb or
cmyk,
I worked for a while doing proofs for a company that makes foil lids,
and
there were plenty of 'extra' colours (luminesents spring to mind)

Now that I'll agree with - but are they really 'colours' as such?

Well I consider them so. To me the 'colour' of an object is defined only
by the light coming from it.

Btw, can the human eye distinguish between yellow light and a similar
combination of red and green?
On a frequency/intensity plot the two situations would look very
different, but
the assumption that they appear same seems fundemental to rgb
representation
of colour.

--
Jim H jh
@333
.org

On Tue, 13 Jan 2004 09:35:59 +0000, Ian Molton wrote:

On Tue, 13 Jan 2004 01:47:21 -0000
Jim H wrote:


Icidently, I agree completely that there are colours outside of rgb or
cmyk,
I worked for a while doing proofs for a company that makes foil lids,
and
there were plenty of 'extra' colours (luminesents spring to mind)

Now that I'll agree with - but are they really 'colours' as such?

Well I consider them so. To me the 'colour' of an object is defined only
by the light coming from it.

Btw, can the human eye distinguish between yellow light and a similar
combination of red and green?
On a frequency/intensity plot the two situations would look very
different, but
the assumption that they appear same seems fundemental to rgb
representation
of colour.

--
Jim H jh
@333
.org