Digital BW, The Print

So, for those of us who are not as deeply into the technology as many 
on the list, what is the "bottom line" here.  Is there any real 
advantage to sending files to the Epson driver at precisely 360 dpi.  
I tend to scan at the maximum resoulution for my LS-2000 which means 
the resolution of files printed at 5X7 or even somewhat larger is 
around 400 dpi.  

Thanks,

Steve

Hi Steve,

> So, for those of us who are not as deeply into the technology as many
> on the list, what is the "bottom line" here.  Is there any real
> advantage to sending files to the Epson driver at precisely 360 dpi.

That depends on what your printer is.  The printers that print max ~44",
like the desktop printers claim to upsample to 720.  It's only the large
format printers (max print length ~88") that are 360.

It also depends on what driver you are using.  For the Piezo driver, no,
just send it what ever PPI you get, and do not resample when you resize.
Either way, (Epson or Piezo), you should still scan at the optical
resolution of your scanner.

Now, for the Epson driver, I would simply suggest testing it out on your
own, as the results may vary from printer to printer, and even image to
image.  There appear the be three things you can do:

1) resize without resampling, and send the data to the printer driver and
let it resample.

2) resize and resample (PS resample algorithm of your choice) to 720 for
desktop printer, and send 720 to the print driver.

3) resize without resampling, and resample using one of the aftermarket
resamplers to resample to 720...they may even resize for you as well.

I don't print B&W using the Epson driver, so I have no idea how good/bad it
is, but I would be interested in what you, or anyone else, who prints with
the Epson driver, finds out if you do run some tests.

Regards,

Austin

Not really Stephen. 240-300 is just fine for photographs.

Jerry

Stephen Kobrin wrote:

> So, for those of us who are not as deeply into the technology as many 
> on the list, what is the "bottom line" here.  Is there any real 
> advantage to sending files to the Epson driver at precisely 360 dpi.  
> I tend to scan at the maximum resoulution for my LS-2000 which means 
> the resolution of files printed at 5X7 or even somewhat larger is 
> around 400 dpi.  
> 
> Thanks,
> 
> Steve 
> 
> 
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Stephen,

The advice from Kennedy McEwan (who has studied this in some detail) on
another list is that if your ppi is below 240, you should upsample using PS
bicubic to 360 ppi. If it is above 480 ppi, you should downsample to 360
using PS bicubic. If it is between 240 and 480, you should leave it as it
is.

Nice and simple.  For desktop Epsons (that use 720 internally).

Large-format Epsons that use 360 internally, may need different advice.

Bob Frost.

>
> Stephen Kobrin wrote:
> > So, for those of us who are not as deeply into the technology as many
> > on the list, what is the "bottom line" here.  Is there any real
> > advantage to sending files to the Epson driver at precisely 360 dpi.
> > I tend to scan at the maximum resoulution for my LS-2000 which means
> > the resolution of files printed at 5X7 or even somewhat larger is
> > around 400 dpi.

> If it is above 480 ppi, you should downsample to 360
> using PS bicubic.

Bob,

If this is for the ones that use 720 internally, why would you not upsample
to 720, instead of losing detail by downsampling to 360?

Austin

Thanks Bob, that is clear as a bell and makes sense, at least to me.

Steve
--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Bob Frost" 
<bobfrost@b...> wrote:
> Stephen,
> 
> The advice from Kennedy McEwan (who has studied this in some 
detail) on
> another list is that if your ppi is below 240, you should upsample 
using PS
> bicubic to 360 ppi. If it is above 480 ppi, you should downsample 
to 360
> using PS bicubic. If it is between 240 and 480, you should leave it 
as it
> is.
> 
> Nice and simple.  For desktop Epsons (that use 720 internally).
> 
> Large-format Epsons that use 360 internally, may need different 
advice.
> 
> Bob Frost.
> 
> 
> >
> > Stephen Kobrin wrote:
> > > So, for those of us who are not as deeply into the technology 
as many
> > > on the list, what is the "bottom line" here.  Is there any real
> > > advantage to sending files to the Epson driver at precisely 360 
dpi.
> > > I tend to scan at the maximum resoulution for my LS-2000 which 
means
> > > the resolution of files printed at 5X7 or even somewhat larger 
is
> > > around 400 dpi.

Austin,

Because, according to Kennedy, funny things can happen if you print at 720
or near it. I'll try and find the details he posted.

Bob Frost.

----- Original Message -----
From: "Austin Franklin" <darkroom@...>

>
> > If it is above 480 ppi, you should downsample to 360
> > using PS bicubic.
>
> Bob,
>
> If this is for the ones that use 720 internally, why would you not
upsample
> to 720, instead of losing detail by downsampling to 360?

Austin,

Found one ref -

>I'm beginning to understand what goes on now. BUT, if the printer driver is
>going to resample to 720 ppi (desktop printers) and PS does a better job of
>resampling (as you say below), then why don't you recommend that we all
>resample our images in PS to 720 ppi before sending them to the printer?

"Several reasons, some of which are just as relevant as always, but
others become less relevant as the technology moves on.  In that latter
category are definitely issues about file size and processing speed.  A
couple of years ago with less than 100MB being a lot of memory and
processor speeds of the time, resampling to 720ppi would have been an
unnecessary burden - if at all practical for many systems to cope with.
With todays speeds and memory allocations, that is not as much of an
issue, but a lot of machines will still struggle.

In the former category are consequences of the stochastic dither
algorithm used by Epson, which can produce unwanted fine detail
enhancement if sent data at full resolution.  This can often result in
unexpected granularity in the image which is similar but not the same as
grain aliasing.  Another aspect is the printer settings itself which may
result in a slight scaling if set incorrectly, resulting in very large
alias patterns which are well within visible resolution limits with
720ppi source material.  Although I didn't cover these in the previous
response, they are things I have raised in previous discussions on this
topic."

From a post by Kennedy McEwan on Epsonx&x

----- Original Message -----
From: "Austin Franklin" <darkroom@...>
> Bob,
>
> If this is for the ones that use 720 internally, why would you not
upsample
> to 720, instead of losing detail by downsampling to 360?