Re: A3 prints from *istD

[Peter J. Alling]

Peter J. Alling wrote:
William Robb wrote:


Photography was so much easier when it was about photography.
William Robb

 

Photography was never about photography...

--
Politicians are interested in people. Not that this is a virtue. Fleas are interested 
in dogs.
   P. J. O'Rourke

Re: A3 prints from *istD

[Toralf Lund]

Caveman wrote:
Toralf Lund wrote:
And no matter which way you look at it, you cannot extend the 
bandwidth. Which is why I say interpolation doesn't change the 
resolution.

Depends what your definition for resolution is. If you define it as 
the size of the smallest details that can be recorded, then you're 
right. But the film guys would say that you're talking about resolving 
power not resolution. If you define it as number of pixels (per inch) 
then it doesn't make sense.
Well. I originally used the term loosely, or without thinking, but I was 
trying to talk about the actual resolution of the data as opposed to the 
number of pixels in the file. And of course, when we talk about 
resolution of scans, we always mean *optical* resolution, or the level 
of detail in the data captured. "Interpolated resolution" is not a term 
you use if you're professional about this...


Mathematically, interpolation is the estimation of  a function based 
on certain known function values.

Yes I know, what we have here again is a problem of language abuse.
What is important to know is that the ideal reconstruction (or 
"interpolation" that guesses 100% right) is done with a sum of 
weighted sinc functions (something like a sum of p*sin(x)/x terms, one 
per each pixel in the image).
Or a bit more complicated. Or maybe this is an approximation, too. 
What's you'd need to use is probably a Fourier series, which is a sum 
involving sin and cos, but not exactly the way you describe it (Argh. I 
don't remember the exact expression. It's been way to long since I did 
tels. But it's something like a weighted sum of (cos(nx) + sin(nx)) for 
n=1, ...)

That would be a Fourier series, I think. As I thought I should have said 
after I sent my last mail, yes, you do indeed get a signal filtered 
through a low-pass filter, if that's how you choose to see, and you 
should be able to give a 100% accurate representation of that signal 
using a Fourier series. But, seeing the traditional interpolation 
algorithms as attempts at an approximation of that series is drawing it 
way to far, I think. Interpolation is a much more practical or ad-hoc 
process.

Since this takes ages to compute, you use approximations of this 
functions in the form of "bicubic" "bilinear" or "nearest". They 
compute much faster but are not perfect i.e. they give some slightly 
wrong guesses (artifacts).
OK, OK. You can in a way see these as approximations of the Fourier, 
since you *know* that's the right function. Unless you actually want to 
do something else than representing the "filtered" data; you could be 
trying to estimate the *unfiltered* version, too. At any rate, I'd say 
it's all about choosing a polynomial function based on a limited region 
of the picture because you know that generally gives you a decent 
estimate - not because you see it (mathematically) as a simplification 
or approximation of a specific known function.

Now if you explore some really proffesional image processing software 
(like the kind used for satellite imagery), you'll notice that the 
"sinc" method is available too. Recommended of course to be used only 
with parallel computing clusters.
Hmmm. Maybe that one is a serious attempt at something Fourier-like...
cheers !

Re: A3 prints from *istD

[John Francis]

> 
> >As has already been pointed out, printing with wet inks (the technology
> >basis for home inkjet printers) is limited by the paper; ink spreads and
> >merges before it dries.  Even the 200-300 dpi figure above is generous
> >when it comes to positioning acuracy (wet paper stretches significantly).
> >
> >A high clay content glossy photo paper is as resistant to ink spread
> >as most things, although plastic film will do a little better.  But
> >you also run into the problem of adjacent droplets merging together
> >before they have had time to dry, which constrains the final figure.
> >  
> >
> Mightn't that reduce the "pixelation" effect, i.e. produce an effect 
> somewhat similar to pixel interpolation?

You don't see pixelation effects on 600dpi (or even 300dpi) printing.
Most artifacts like that are caused by upsizing from lower-resolution
data, and can be pretty much avoided by smarter upsizing software.
> 
> But how about real photo paper, i.e. the variant(s) used by labs and/or 
> traditional enlargers rather than the inkjet version? 

They don't print with wet inks, so there's no comparable problem.

> Also, would laser printers give better results because the process (as I 
> understand it) is a lot "drier"?

They don't have the problems caused by ink spreading.  But, in turn,
they don't get the benefit of inkdrop merging, either, so they often
have a smaller number of discrete colour values at any given pixel
(and it's much harder to get a uniform intensity ramp with dry toner).

Re: A3 prints from *istD

[Toralf Lund]

Toralf Lund wrote:
Caveman wrote:
[ Long and meaningless discussion... ]
- the "real" formula computes level at point x,y based on the values 
of *all* the samples of the image

What you are talking about here is probably an n-degree polynomial, 
where n is the number of pixels or samples.
Or maybe it's n-1. But not necessarily, come to think of it; this is the 
highest degree possible, but you may perfectly well use n values to 
estimate a polynomial with an less than n-1...

Might give you good results, but it's still an approximation. And I' 
not sure you can automatically assume that the data will be more 
correct than what you get if using lower-degree polynomials within 
smaller regions.

- bicubic computes level at point x,y based on the values of the 
samples in a 4x4 vicinity of point x,y (and discards from computation 
all the other samples)

That would be a 3rd degree polynomial (in 2 dimensions.)
Or you could actually use e.g. linear based on 4 points (see above)
[ ... ]
Right. And all this from a small aside...

Re: A3 prints from *istD

[Caveman]

Toralf Lund wrote:
And no matter which way you look at it, you cannot extend the bandwidth. 
Which is why I say interpolation doesn't change the resolution.
Depends what your definition for resolution is. If you define it as the 
size of the smallest details that can be recorded, then you're right. 
But the film guys would say that you're talking about resolving power 
not resolution. If you define it as number of pixels (per inch) then it 
doesn't make sense.

Mathematically, interpolation is the estimation of  a function based on 
certain known function values.
Yes I know, what we have here again is a problem of language abuse.
What is important to know is that the ideal reconstruction (or 
"interpolation" that guesses 100% right) is done with a sum of weighted 
sinc functions (something like a sum of p*sin(x)/x terms, one per each 
pixel in the image).

Since this takes ages to compute, you use approximations of this 
functions in the form of "bicubic" "bilinear" or "nearest". They compute 
much faster but are not perfect i.e. they give some slightly wrong 
guesses (artifacts).

Now if you explore some really proffesional image processing software 
(like the kind used for satellite imagery), you'll notice that the 
"sinc" method is available too. Recommended of course to be used only 
with parallel computing clusters.

cheers !

Re: A3 prints from *istD

[Toralf Lund]

Caveman wrote:

Toralf Lund wrote:
I think the real situation is that the camera does not capture 
according to the sampling theorem, i.e. the data has a frequency a 
lot higher than half of your sample rate, so you're not going to be 
able to reproduce the input accurately (according to Nyquist.)

I mentioned "ideal" case. If we want to speak reality, you have the 
lens and an optical lowpass filter sitting in front of the sensor. The 
manufacturer is supposed to combine the MTF of the lens with the one 
of the filter in order to have a band limited signal on the sensor.

So what you should be able to reconstruct using an ideal sensor would 
be the band limited image formed on the sensor plane and not the real 
image in the outside world.
And no matter which way you look at it, you cannot extend the bandwidth. 
Which is why I say interpolation doesn't change the resolution.

But then we have the sensor itself. The photosites are not infinitely 
small so you don't have an ideal sampling. However you could 
approximate the effect of the finite size of the photosites as yet 
another lowpass filter. Then you have sensor and circuitry noise, 
which will give you yet another approximation. Then you have 
quantization errors. Etc.

So finally you get some approximative data that's more or less close 
to the ideal sampling of ideally low pass filtered image.


Are you sure that's right? Isn't the interpolation more about 
guessing what values you would have got, if sampling at a higher rate 
- by assuming the signal (pixel data) develops according to a certain 
well-known function?

It's not wild guessing, they are approximations of the real formula.

You could use that formula and it would give you "the perfect guess" 
i.e. reconstruction. However that one is very computational intensive, 
and since you're starting with a non-ideal set of samples, the 
benefits would not be that great.
I'm not sure I understand why we have to drag Nyquist into this. Maybe 
I'm too simplistic, but I really like to see interpolation as just a way 
of giving an estimate of what additional data might look like, without 
thinking about bandwidths etc.  I'd much rather say "Newton" instead, if 
I had to mention a name...

Mathematically, interpolation is the estimation of  a function based on 
certain known function values. Furthermore, a function value f(x) is 
called an *interpolation* if there are a number of values in the range 
x1 ... xn (where xn>x1) for which the function values are known, and x 
lies between x1 and xn. If x is outside the range, f(x) is an 
*extrapolation*. The point is, f(x) cannot be accurately determined 
because there is an infinite number of functions that may fit. However, 
it has been shown that a polynomial function is often a good 
approximation; if you set up an n'th degree polynomial that would give 
the correct function values at your known points x1 ... 
xn/f(x1)...f(xn), you will often get a good estimate of the function 
value at some other point by applying the same polynomial function - but 
again, it's an *estimate*, you can't actually know if you're right, and 
there is no such thing as the "real formula". And one challenge is 
choosing the value of n. In pixel interpolation, essentially you often 
treat the data as separate sets of measurements approximated with 
separate sets of functions, and the trick to it all is knowing how to 
split up your data, of if you like, knowing what degree polynomial to 
assume.

- the "real" formula computes level at point x,y based on the values 
of *all* the samples of the image
What you are talking about here is probably an n-degree polynomial, 
where n is the number of pixels or samples. Might give you good results, 
but it's still an approximation. And I' not sure you can automatically 
assume that the data will be more correct than what you get if using 
lower-degree polynomials within smaller regions.

- bicubic computes level at point x,y based on the values of the 
samples in a 4x4 vicinity of point x,y (and discards from computation 
all the other samples)
That would be a 3rd degree polynomial (in 2 dimensions.)

-bilinear computes level at point x,y based on the values of the 
samples in a 2x2 vicinity of point x,y
Yes, 1st degree or linear interpolation. It actually gives you good 
results in many cases, an the effect is rather similar to the one of 
letting adjacent pixels float into each other...

- nearest neighbour computes level at point x,y based on the value of 
1 pixel (it just copies the value of the closest sample)

So now you got an idea of what the approximations are and how they are 
done.

Re: A3 prints from *istD

[Toralf Lund]

John Francis wrote:
On Aug 28, 2004, at 12:08 PM, Doug Franklin wrote:
   

On Fri, 27 Aug 2004 20:09:45 +0200, Toralf Lund wrote:
 

[...] to get real picture quality, you ought to have enough
information to print at 1200dpi [...]
   

Most paper can't hold more than 200-300 dpi.
 

Just to be pedantic...
DPI (dots per inch) applies mainly to halftone processes such as inkjet 
printers.  It refers to the minimum offset distance between two dots.  
Each of the two dots can be any component colour (usually C, M, Y, K).  
So the higher the dpi figure, the closer the dots can be printed 
together, and the "smoother" the image will look from close up.

PPI (pixels per inch) describes the amount of actual information 
present in the image.

Continuous-tone processes are an exception as the component colours are 
placed on top of each other, so in this case dpi and ppi can be used 
interchangeably as the numbers are equal anyway.  Scanners and digital 
minilabs work this way.  I think dye-sub printers are like this, too.
   

Yep. I must admit we usually talk about DPI (not PPI) where I work... 
(See http://www.procaptura.com.)

Marketing people love to create confusion between these concepts... 
which is why people tend to refer to dpi all the time as this gives the 
bigger numbers.
   

As has already been pointed out, printing with wet inks (the technology
basis for home inkjet printers) is limited by the paper; ink spreads and
merges before it dries.  Even the 200-300 dpi figure above is generous
when it comes to positioning acuracy (wet paper stretches significantly).
A high clay content glossy photo paper is as resistant to ink spread
as most things, although plastic film will do a little better.  But
you also run into the problem of adjacent droplets merging together
before they have had time to dry, which constrains the final figure.
 

Mightn't that reduce the "pixelation" effect, i.e. produce an effect 
somewhat similar to pixel interpolation?

The bottom line is that even the 600ppi (base figure for the HP line
of 1200x4800 dpi photo printers) or the comparable 720ppi from Epson
is overkill for printing multi-coloured images on everyday media.
 

But how about real photo paper, i.e. the variant(s) used by labs and/or 
traditional enlargers rather than the inkjet version? (Or was that what 
you were referring to above?)

Also, would laser printers give better results because the process (as I 
understand it) is a lot "drier"?

Not to mention that 600ppi for a 13x19 image takes 1/4 GB of data.
 

My point exactly.

Re: A3 prints from *istD

[David Mann]

On Aug 28, 2004, at 12:08 PM, Doug Franklin wrote:
On Fri, 27 Aug 2004 20:09:45 +0200, Toralf Lund wrote:
[...] to get real picture quality, you ought to have enough
information to print at 1200dpi [...]
Most paper can't hold more than 200-300 dpi.
Just to be pedantic...
DPI (dots per inch) applies mainly to halftone processes such as inkjet 
printers.  It refers to the minimum offset distance between two dots.  
Each of the two dots can be any component colour (usually C, M, Y, K).  
So the higher the dpi figure, the closer the dots can be printed 
together, and the "smoother" the image will look from close up.

PPI (pixels per inch) describes the amount of actual information 
present in the image.

Continuous-tone processes are an exception as the component colours are 
placed on top of each other, so in this case dpi and ppi can be used 
interchangeably as the numbers are equal anyway.  Scanners and digital 
minilabs work this way.  I think dye-sub printers are like this, too.

Marketing people love to create confusion between these concepts... 
which is why people tend to refer to dpi all the time as this gives the 
bigger numbers.

Cheers,
- Dave
http://www.digistar.com/~dmann/

Re: A3 prints from *istD

[Brendan]

 I have yet to try a a3 off the *istD on my 2200 but
the A4's look very good! from what I have seen a 36x24
won't be too difficult to do once proper care ( and a
good original shot! )


--- Dario Bonazza <[EMAIL PROTECTED]> wrote: 
> Jostein wrote:
> 
> > So I got curious. I asked a pro-lab in Oslo to go
> as large as _they_
> > considered reasonable quality, and told them the
> file was from a 6
> > Mpix DSLR. They print on a Epson Pro 9600. What I
> got back was an A2
> > enlargement. At this size, it was easy to spot the
> blurring of details
> > less than 3 pixels across. The Pentax way of
> anti-aliasing made them
> > blend together. There were no artificial coloring
> or moire, though.
> > Another gripe was that contrast got a bit out of
> hand, so that dark
> > detail became jagged edges or little squares, 2-3
> pixels across.
> 
> They (you) had to interpolate the file up before
> printing, just to keep 200
> to 300 dpi! That way you can ALWAYS get rid of
> visible pixelation (no extra
> detail though).
> 
> Dario Bonazza
> 
>  

__ 
Post your free ad now! http://personals.yahoo.ca

Re: A3 prints from *istD

[Dario Bonazza]

Jostein wrote:

> So I got curious. I asked a pro-lab in Oslo to go as large as _they_
> considered reasonable quality, and told them the file was from a 6
> Mpix DSLR. They print on a Epson Pro 9600. What I got back was an A2
> enlargement. At this size, it was easy to spot the blurring of details
> less than 3 pixels across. The Pentax way of anti-aliasing made them
> blend together. There were no artificial coloring or moire, though.
> Another gripe was that contrast got a bit out of hand, so that dark
> detail became jagged edges or little squares, 2-3 pixels across.

They (you) had to interpolate the file up before printing, just to keep 200
to 300 dpi! That way you can ALWAYS get rid of visible pixelation (no extra
detail though).

Dario Bonazza

RE: A3 prints from *istD

[Anders Hultman]

On Thu, 26 Aug 2004, Don Sanderson wrote:

> Jostein what's the size in MM (or inches) of A2/A3?

A4210 x 297 mm 8.3 x 11.7 in
A3297 x 420 mm11.7 x 16.5 in
A2420 x 594 mm16.5 x 23.4 in

A4 is the standard sheet of writing, copy etc paper in this part of the
world. A3 is the double size and A2 is the double of that.

The A paper system is defined so that A0 is exactly one square meter with
the height/witdh ratio of one to the square root of two. Fold an A0 in
half and you get A1, fold an A1 in half and you get A2 etc.

anders
-
http://anders.hultman.nu/
med dagens bild och allt!

RE: A3 prints from *istD

[Don Sanderson]

Thanks t

> -Original Message-
> From: Pix [mailto:[EMAIL PROTECTED]
> Sent: Thursday, August 26, 2004 6:02 PM
> To: Pentax Discussion List
> Subject: Re: A3 prints from *istD
> 
> 
> 
> Here's a handy reference that discusses the ISO paper sizes:
> 
> <http://www.cl.cam.ac.uk/~mgk25/iso-paper.html>
> 
> Maybe more than you wanted, but the sizes in mm are there, too.
> 
> t
> 
> On 8/26/04 14:24, Don Sanderson wrote:
> 
> > Jostein what's the size in MM (or inches) of A2/A3?
> > 
> > Don
> > 
> >> -Original Message-
> >> From: Jostein [mailto:[EMAIL PROTECTED]
> >> Sent: Thursday, August 26, 2004 3:42 PM
> >> To: [EMAIL PROTECTED]
> >> Subject: A3 prints from *istD
> >> 
> >> 
> >> Gang,
> >> 
> >> A while ago, I questioned whether files from *istD would suffice for
> >> A3 enlargement. I put a full size version of this image online:
> >> 
> >> http://www.oksne.net/paw/wintermarsh.html
> >> 
> >> The image is so full of minute detail that I had my doubts it could be
> >> blown up larger than A4.
> >> 
> >> Cotty and Paul Stenquist set out to prove me wrong. A couple of days
> >> later I received a print from Paul made on an Epson 2200 onto a
> >> radiant white watercolour paper. The quality was excellent, even to my
> >> prejudice mind. Cotty had printed on glossy paper with his Canon (I
> >> forget the model), and thus the two prints were hard to compare for
> >> differences among the printers. However, the two results clearly
> >> showed that A3 enlargements are well within reach with a 6 Mpix
> >> camera.
> >> 
> >> So I got curious. I asked a pro-lab in Oslo to go as large as _they_
> >> considered reasonable quality, and told them the file was from a 6
> >> Mpix DSLR. They print on a Epson Pro 9600. What I got back was an A2
> >> enlargement. At this size, it was easy to spot the blurring of details
> >> less than 3 pixels across. The Pentax way of anti-aliasing made them
> >> blend together. There were no artificial coloring or moire, though.
> >> Another gripe was that contrast got a bit out of hand, so that dark
> >> detail became jagged edges or little squares, 2-3 pixels across. The
> >> ghosts of Nyquist came out and said boo... Still around the
> >> theoretical limit, I suppose.
> >> 
> >> BUT! from a 50-60 cm viewing distance, even the A2 is passable for
> >> hanging on a wall. By my standards, of course. Ymmv, my expectations
> >> were that this was a no-go.
> >> 
> >> I must say I'm puzzled, astonished and impressed with the result, and
> >> relieved to have been proven wrong in my suspicions.
> >> 
> >> So now I'm seriously considering an A3 printer...:-)
> >> 
> >> Jostein
> >> 
> > 
> > 
> > 
> 

Re: A3 prints from *istD

[Cotty]

On 26/8/04, Paul Stenquist, discombobulated, unleashed:

>(By the way, I made a print of your 
>shot for myself. I'm quite fond of it.

Framed and hanging at the top of the stairs :-)




Cheers,
  Cotty


___/\__
||   (O)   | People, Places, Pastiche
||=|www.macads.co.uk/snaps
_

Re: A3 prints from *istD

[Pix]

Here's a handy reference that discusses the ISO paper sizes:



Maybe more than you wanted, but the sizes in mm are there, too.

t

On 8/26/04 14:24, Don Sanderson wrote:

> Jostein what's the size in MM (or inches) of A2/A3?
> 
> Don
> 
>> -Original Message-
>> From: Jostein [mailto:[EMAIL PROTECTED]
>> Sent: Thursday, August 26, 2004 3:42 PM
>> To: [EMAIL PROTECTED]
>> Subject: A3 prints from *istD
>> 
>> 
>> Gang,
>> 
>> A while ago, I questioned whether files from *istD would suffice for
>> A3 enlargement. I put a full size version of this image online:
>> 
>> http://www.oksne.net/paw/wintermarsh.html
>> 
>> The image is so full of minute detail that I had my doubts it could be
>> blown up larger than A4.
>> 
>> Cotty and Paul Stenquist set out to prove me wrong. A couple of days
>> later I received a print from Paul made on an Epson 2200 onto a
>> radiant white watercolour paper. The quality was excellent, even to my
>> prejudice mind. Cotty had printed on glossy paper with his Canon (I
>> forget the model), and thus the two prints were hard to compare for
>> differences among the printers. However, the two results clearly
>> showed that A3 enlargements are well within reach with a 6 Mpix
>> camera.
>> 
>> So I got curious. I asked a pro-lab in Oslo to go as large as _they_
>> considered reasonable quality, and told them the file was from a 6
>> Mpix DSLR. They print on a Epson Pro 9600. What I got back was an A2
>> enlargement. At this size, it was easy to spot the blurring of details
>> less than 3 pixels across. The Pentax way of anti-aliasing made them
>> blend together. There were no artificial coloring or moire, though.
>> Another gripe was that contrast got a bit out of hand, so that dark
>> detail became jagged edges or little squares, 2-3 pixels across. The
>> ghosts of Nyquist came out and said boo... Still around the
>> theoretical limit, I suppose.
>> 
>> BUT! from a 50-60 cm viewing distance, even the A2 is passable for
>> hanging on a wall. By my standards, of course. Ymmv, my expectations
>> were that this was a no-go.
>> 
>> I must say I'm puzzled, astonished and impressed with the result, and
>> relieved to have been proven wrong in my suspicions.
>> 
>> So now I'm seriously considering an A3 printer...:-)
>> 
>> Jostein
>> 
> 
> 
> 

Re: A3 prints from *istD

[Mark Roberts]

"Jostein" <[EMAIL PROTECTED]> wrote:

>A while ago, I questioned whether files from *istD would suffice for
>A3 enlargement. I put a full size version of this image online:
>
>http://www.oksne.net/paw/wintermarsh.html
>
>The image is so full of minute detail that I had my doubts it could be
>blown up larger than A4.
>
>Cotty and Paul Stenquist set out to prove me wrong. A couple of days
>later I received a print from Paul made on an Epson 2200 onto a
>radiant white watercolour paper. The quality was excellent, even to my
>prejudice mind. Cotty had printed on glossy paper with his Canon (I
>forget the model), and thus the two prints were hard to compare for
>differences among the printers. However, the two results clearly
>showed that A3 enlargements are well within reach with a 6 Mpix
>camera.

>I must say I'm puzzled, astonished and impressed with the result, and
>relieved to have been proven wrong in my suspicions.
>
>So now I'm seriously considering an A3 printer...:-)

Jostein, where were you at Grandfather Mountain when I was passing
around my Super B3 (13 x 19 inches or 33 x 48 cm) prints from the Epson
1270? Several of them were ist-D shots.

-- 
Mark Roberts
Photography and writing
www.robertstech.com

RE: A3 prints from *istD

[Don Sanderson]

Jostein what's the size in MM (or inches) of A2/A3?

Don

> -Original Message-
> From: Jostein [mailto:[EMAIL PROTECTED]
> Sent: Thursday, August 26, 2004 3:42 PM
> To: [EMAIL PROTECTED]
> Subject: A3 prints from *istD
> 
> 
> Gang,
> 
> A while ago, I questioned whether files from *istD would suffice for
> A3 enlargement. I put a full size version of this image online:
> 
> http://www.oksne.net/paw/wintermarsh.html
> 
> The image is so full of minute detail that I had my doubts it could be
> blown up larger than A4.
> 
> Cotty and Paul Stenquist set out to prove me wrong. A couple of days
> later I received a print from Paul made on an Epson 2200 onto a
> radiant white watercolour paper. The quality was excellent, even to my
> prejudice mind. Cotty had printed on glossy paper with his Canon (I
> forget the model), and thus the two prints were hard to compare for
> differences among the printers. However, the two results clearly
> showed that A3 enlargements are well within reach with a 6 Mpix
> camera.
> 
> So I got curious. I asked a pro-lab in Oslo to go as large as _they_
> considered reasonable quality, and told them the file was from a 6
> Mpix DSLR. They print on a Epson Pro 9600. What I got back was an A2
> enlargement. At this size, it was easy to spot the blurring of details
> less than 3 pixels across. The Pentax way of anti-aliasing made them
> blend together. There were no artificial coloring or moire, though.
> Another gripe was that contrast got a bit out of hand, so that dark
> detail became jagged edges or little squares, 2-3 pixels across. The
> ghosts of Nyquist came out and said boo... Still around the
> theoretical limit, I suppose.
> 
> BUT! from a 50-60 cm viewing distance, even the A2 is passable for
> hanging on a wall. By my standards, of course. Ymmv, my expectations
> were that this was a no-go.
> 
> I must say I'm puzzled, astonished and impressed with the result, and
> relieved to have been proven wrong in my suspicions.
> 
> So now I'm seriously considering an A3 printer...:-)
> 
> Jostein
>