Digital BW, The Print

For what it's worth--

I had downloaded the JPEG image only and on my calibrated LaCie 21" 
the banding was quite visible in the upper left target at 100%.  So I 
printed the target through QTR with three profiles.  The first was 
Cone's linearization (for the 4800/NK7) with no other profile; the 
second with the Cone profile and my own 21x4 random QTR ICC; and the 
third with the Cone profile and my own 51 random QTR ICC.  With the 
first two the printed target looked quite smooth.  With the third, 
the banding seen on the screen was quite visible in the print.

So I'm not quite sure what this speaks to.

Walt


--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "John Moody" 
<moodymz3@...> wrote:
>
> The PS gradient does not band.  I believe you are looking at a less 
than
> optimal monitor and/or calibration.  Your crt should not be that 
bad; you
> are setting the white point of the monitor with it's controls, and
> calibrating to native white point, yes?
> 
> I assume you are working with the 16-bit generated gradient, not 
the jpeg.
> View at 800% and select a small area of the gradient where you see 
banding
> (gradient reversals), and do an "auto levels" on the selection.  
You should
> see that the gradient steps are not banded.  You can also set the 
info
> palette to show 16-bit values, and "go-by-the-numbers" to see that 
there are
> no reversals.
> 
> I would convert to 8-bit before printing with QTR.
> 
> Best regards,
> John Moody
> 
> -----Original Message-----
> From: DigitalBlackandWhiteThePrint@yahoogroups.com
> [mailto:DigitalBlackandWhiteThePrint@yahoogroups.com]On Behalf Of 
gp295
> Sent: Wednesday, December 13, 2006 6:36 PM
> To: DigitalBlackandWhiteThePrint@yahoogroups.com
> Subject: [Digital BW] Re: New linearization test image uploaded
> 
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com
> <mailto:DigitalBlackandWhiteThePrint%
40yahoogroups.com> , "robert49brake"
> <robert49brake@> wrote:
> >
> >
> > I'd also be interested in hearing from others whether or not
> > the banding might just be inherent in the gradient structure of 
PS.
> 
> Robert.
> 
> I think you may have nailed down the problem in your post. I went
> back and looked at the targets more critically on-screen, and when i
> zoomed to Actual Pixels i could see the banding quite clearly.
> (Pretty much as clearly as i could see it in my prints.)
> 
> Although it was less obvious, unlike you i thought i could see some
> banding in the linear ramp when it was also viewed at 100%. Thinking
> it might be less obvious simply because my linear ramp was narrower,
> i quickly made a full-page linear ramp, and on this image the 
banding
> was as clear as it was on the circular ones.
> 
> So it does seem as if the banding problem is something inherent in
> the way PS creates gradients. And in my view it occurs in both 
Radial
> and Linear Gradients. I'm surprised i never noticed this before, but
> i guess i just never inspected PS gradients on-screen at that
> magnification until now.
> 
> In fact, when i zoomed to 500%, i realised that the banding also
> occurs at a smaller scale as well, though this is not really obvious
> to the naked eye because the steps are only about half a millimeter
> wide.
> 
> Like you, i'd be interested to know if other people confirm what we
> think. I'd also be interested to know what people feel about the
> usefulness (or otherwise) of my test images, given this (fairly
> significant) drawback. If the test-files encourage people to see
> problems where there aren't any, it would probably be best to remove
> them from the site. (Who's going to remember this explanation in 
five
> year's time?)
> 
> Thanks for passing on the explanation, Robert. For the record, i'm
> using a calibrated LaCie Electron Blue IV CRT monitor.
> 
> Best.
> 
> graham
> 
> 
> 
> [Non-text portions of this message have been removed]
>