Epson printers - 2400 vs. 4800 ??

Nicholas O. Lindan wrote:

Mark² wrote:


I still challenge anyone to produce evidence that ANY media will show the
useful exhibition of 9600dpi from an ink jet type printer.



Don't confuse dpi [random tiny dots] and pixels [resolved information].

300 pix/inch is what most printers actually provide. Try printing a
test target and look with a loupe. For all practical purposes
300 pixels/inch is really all that is needed.

9600 dpi at 300 pix/inch gives 1024 dots/pixel [the number of dots
in a square pixel is the square of the number of dots along each side].
If we print only magenta dots then there can 1024 shades of magenta.
256 shades, the minimum for colors to look smoothly gradated, requires
8 dots/pix-inch resulting in a true 1200 pixels/inch.

With a 1200 dpi printer at 300 pix/inch there are 16 dots/pixel
and only 16 shades of a pure primary color are possible. To overcome
this limitation the printer blends adjacent pixels to make intermediate
shades and the printer is really doing ~75 pix/inch to get saturated
colors. The printers also mix dot colors [pure magenta at 50% will have
yellow and cyan dots in it] to make more shades of a color
but the color is now unsaturated.

As a result, until high dpi printers became available one had a choice
of snappy colors at a low resolution or sharp pictures but blah colors.

This is also why black & white is so hard to do will with an ink-jet
printer with low dpi: 16 shades of grey just doesn't make it. Color
is added to vary the apparent density but then the grays change their
tint when viewed by a different light and the eye is not well fooled
by the color dithering -- yellow + cyan + magenta = dark muddy brown.

As a further complication, an inkjet printer builds linear reflectance:
25% dots = 25% reflectance, 50% dots = 50% reflectance. The eye,
however perceives logarithmically ["God invented logarithms, man
invented the integers." - somebody famous] and the shades are not
equally spaced. If black is 2.0 OD:

printer #black dots/pix OD
9600 dpi/300 pix/inch printer 1024 2.00
1023 1.96
1 0.00042
0 0.00

1200 dpi/300 pix/inch printer 16 2.00
15 1.14
14 0.87
1 0.03


You are one one thousandth off

0 0.00

As is easy to see, there is no possibility for shadow detail in a 1200 dpi
printer.

If you use 8 bit software, though, you are often limited to 256 shades.

# black dots/pix OD Zone Shades/Zone change
255 2.0 0
254 1.86 I 1
251 1.59 II 3
245 1.31 III 6 - detailed black
232 1.00 IV 13 - dark grey
1 0.0017
0 0.00

Easy to see why so many digital photos have no shadow detail.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
To reply, remove spaces: n o lindan at ix . netcom . com
Fstop timer - http://www.nolindan.com/da/fstop/index.htm

On Fri, 06 Jan 2006 20:46:27 GMT, "Nicholas O. Lindan"
wrote:


Easy to see why so many digital photos have no shadow detail.


As dot-placement resolutions go up, I would think
the "effective contone bit-depth per unit area" would
follow, in proportion to dots/unit area.

Hey, I like that term... "effective contone bit-depth
per unit area." Has a ring to it.

Halftoning and error diffusion are not trivial topics.
Lots of PhDs working on that stuff nowadays. There
are a couple of firmware engineers at my workplace
dedicated to just that.

Plus there are some nice contone digital imaging
systems available to all, eg. LED or laser imaging
on photo paper and thermal (dye-sub.) The latter
is already used in household printers, albeit usually
for very small prints.


rafe b
www.terrapinphoto.com

Kennedy McEwen wrote:
In article n5mvf.7911$V.719@fed1read04, Mark²
writes
Kennedy McEwen wrote:
In article w9bvf.7874$V.6727@fed1read04, Mark²
writes

I contend that there isn't ANY media capable of showing a benefit
of dpi that high.

There are plenty of such media, they just aren't papers. :-)

Who said anything about papers?
I still challenge anyone to produce evidence that ANY media will
show the useful exhibition of 9600dpi from an ink jet type printer.

You didn't say anything about injet printers either! ;-)

What is the Canon in question if not an ink-jet type printer (a poorly
selected generic term for ink-based printers, since "ink-jet" tends to refer
only to HP printers...).

Kennedy McEwen wrote:
In article , David
Nebenzahl writes
Kennedy McEwen spake thus:

In article w9bvf.7874$V.6727@fed1read04, Mark²
writes

I contend that there isn't ANY media capable of showing a benefit
of dpi that high.
There are plenty of such media, they just aren't papers. :-)

Like what--stainless steel? Precision-buffed to a high gloss?

I was thinking specifically of chrome on glass at the time I wrote
that, but there are lots of examples. The data on this CD in my PC
is more than 5760dpi and DVDs are even higher. The entire electronic
industry relies on semiconductor media with details on them at higher
dpi still. ;-)

It was a slightly tongue in cheek comment in any case because what
Mark appears to have failed to notice is that the whole point of
printing at such resolutions is that the dots are *NOT* resolved on
the media - it is merely a means to achieve multi-tonal results from
monotone inks in resolutions which are visually perceptible.

No, I quite understand that each dot is not intended as an individually
perceived unit, but rather a basis through which ink is combined to form
perceived color. Still...can anyone point to the realization of a
visually-perceived benefit of 9600dpi over, say, 4800?

Mark² spake thus:

Kennedy McEwen wrote:

In article n5mvf.7911$V.719@fed1read04, Mark²
writes

Kennedy McEwen wrote:

In article w9bvf.7874$V.6727@fed1read04, Mark²
writes

I contend that there isn't ANY media capable of showing a
benefit of dpi that high.

There are plenty of such media, they just aren't papers. :-)

Who said anything about papers? I still challenge anyone to
produce evidence that ANY media will show the useful exhibition
of 9600dpi from an ink jet type printer.

You didn't say anything about injet printers either! ;-)

What is the Canon in question if not an ink-jet type printer (a
poorly selected generic term for ink-based printers, since "ink-jet"
tends to refer only to HP printers...).

They're all inkjets, even those (like Canon) called "bubble jets" or
some such other. Inkjet is a generic term for printers what squirt ink
onto paper (or other substrate), regardless of what the marketroid types
say. (Including "giclée", the ultimate $2 snob-appeal term.) Even
includes some non-consumer types that use solvent-based (as opposed to
water-based) inks.

Not poorly-selected at all; describes how they work admirably.


--
The only reason corrupt Republicans rule the roost in Washington
is because the corrupt Democrats can't muster any viable opposition.

David Nebenzahl wrote:
Mark² spake thus:

Kennedy McEwen wrote:

In article n5mvf.7911$V.719@fed1read04, Mark²
writes

Kennedy McEwen wrote:

In article w9bvf.7874$V.6727@fed1read04, Mark²
writes

I contend that there isn't ANY media capable of showing a
benefit of dpi that high.

There are plenty of such media, they just aren't papers. :-)

Who said anything about papers? I still challenge anyone to
produce evidence that ANY media will show the useful exhibition
of 9600dpi from an ink jet type printer.

You didn't say anything about injet printers either! ;-)

What is the Canon in question if not an ink-jet type printer (a
poorly selected generic term for ink-based printers, since "ink-jet"
tends to refer only to HP printers...).

They're all inkjets, even those (like Canon) called "bubble jets" or
some such other. Inkjet is a generic term for printers what squirt ink
onto paper (or other substrate), regardless of what the marketroid
types say. (Including "giclée", the ultimate $2 snob-appeal term.)
Even includes some non-consumer types that use solvent-based (as
opposed to water-based) inks.

Not poorly-selected at all; describes how they work admirably.

Yes.
And oops... -My tired little brain was thinking of "desk-jet" -which has
been nabbed by HP...not ink-jet.

The real question about companies that claim 9600 dpi inkjet resolution
or what have you is can this be accomplished with the minimum dot size
they offer? In other words, using inkjet media, even with the best
available in terms of minimum dot gain or bleed, could that many dots
occupy the space provided (1/9600th of an inch).

In general, this spec is not stating that this resolution can be created
in a real world situation (such as a photographic image) but that the
printer could "place" any one dot with that accuracy.

Art

Kennedy McEwen wrote:

In article w9bvf.7874$V.6727@fed1read04, Mark²
writes


I contend that there isn't ANY media capable of showing a benefit of
dpi that high.


There are plenty of such media, they just aren't papers. :-)

In article UmFvf.8032$V.3630@fed1read04, Mark²
writes
Kennedy McEwen wrote:
In article n5mvf.7911$V.719@fed1read04, Mark²
writes
Kennedy McEwen wrote:
In article w9bvf.7874$V.6727@fed1read04, Mark²
writes

I contend that there isn't ANY media capable of showing a benefit
of dpi that high.

There are plenty of such media, they just aren't papers. :-)

Who said anything about papers?
I still challenge anyone to produce evidence that ANY media will
show the useful exhibition of 9600dpi from an ink jet type printer.

You didn't say anything about injet printers either! ;-)

What is the Canon in question

An Epson! (read the subject) ;-)
--
Kennedy
Yes, Socrates himself is particularly missed;
A lovely little thinker, but a bugger when he's ****ed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)

In article vtFvf.8033$V.4113@fed1read04, Mark²
writes

No, I quite understand that each dot is not intended as an individually
perceived unit, but rather a basis through which ink is combined to form
perceived color. Still...can anyone point to the realization of a
visually-perceived benefit of 9600dpi over, say, 4800?

Reduces tonal noise at the visual acuity limit, which is all that a
finer dither matrix is intended to achieve.
--
Kennedy
Yes, Socrates himself is particularly missed;
A lovely little thinker, but a bugger when he's ****ed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)

Kennedy McEwen wrote:
In article UmFvf.8032$V.3630@fed1read04, Mark²
writes
Kennedy McEwen wrote:
In article n5mvf.7911$V.719@fed1read04, Mark²
writes
Kennedy McEwen wrote:
In article w9bvf.7874$V.6727@fed1read04, Mark²
writes

I contend that there isn't ANY media capable of showing a benefit
of dpi that high.

There are plenty of such media, they just aren't papers. :-)

Who said anything about papers?
I still challenge anyone to produce evidence that ANY media will
show the useful exhibition of 9600dpi from an ink jet type printer.

You didn't say anything about injet printers either! ;-)

What is the Canon in question

An Epson! (read the subject) ;-)

Yes... But the 9600dpi comment came from a Canon printer comment.
Threads change.
Here's the quote for ya:
Take a look at the Canon iP4200. It'll print at 9600x2400dpi.