Digital BW, The Print

> Todd., this is a phaenomenem which has nothing to do with the drivers. I
> should have mentioned this in my data sheet. It has something to do with the
> grade of magnification of the image in PS. It seems to be a form of
> interference of fine structures (lines) during the sampling/resampling process
> in PS  which appears while creating larer or smaller images. The raw-files of
> the images are the same. The interferrence came up by downscaling the large
> image. If I upscale it again, it disappears. You can reproduce the same
> phaenomenem with the piezo test file (lines pattern) which comes with the
> piezo software, it is visible on the monitor by stepwise magnification. Best
> regards Bernd


Bernd 

I'm familiar with the type of aliasing you are talking about in PS - at
least I think I am - let's see.... And I *think* it's called aliasing, but
I'm not sure of that either.

 What I experience is not related to file size so much as image
magnification. The image has poorer representation on screen at odd
magnifications than even. Thus 33.3% magnification is more aliased than at
50%, and 66.7% is worse than 75%. (This is one reason to never check your
sharpening, or other filters, at those odd magnifications. 100% is the only
"true" test, though 50% and 25% can be useful, but never 33.3% or 66.7%,
etc.)

However this aliasing of which I speak is never present in print. It's
purely a screen representation. I personally have never experienced what I
see in your print from up or down sizing in PS, but then I'm no expert. All
I know is I always use bicubic interpolation for photos, and so far I've
been lucky as such.

But the true test to me would be if an Epson driver print of that same file
(that produced the moiré in the Piezo driver) also produces the moiré. Have
you tried that? 

Thanks,
Todd


>> While we are on the subject of Bernds driver comparison, I saw something in
>> there that I had never seen before. Look at the two smaller prints that were
>> both printed with the Piezo driver. The large smoke stack on the left has a
>> moiré  pattern in it's lower third. It's not there in the Epson driver print,
>> but that is a larger print, so I wouldn't expect them to be the same. But
>> what could be the cause of that moiré ?
>> 
>> Todd
>>