Digital BW, The Print

In a message dated 7/29/2004 3:07:40 AM Eastern Daylight Time, 
DigitalBlackandWhiteThePrint@yahoogroups.com writes:


> I printed a picture with my 2200 UT7 today that has a large area of 
> artifically created gradient (black to 50% grey).
> 
> What i noticed (and its not subtle) is that with all of the curves 
> that i tried for enhanced matt... there is banding (with all curves) 
> throuout the region of 70% (grey) to 100% (black)... the banding is 
> in the form of uneven gradients (banding pattern varies between 
> curves).  its only noticible just in that region and once it gets to 
> the lighter gradient areas, it looks fine.  Is this to be expected 
> for this system? or am i doing something wrong?
> 

You might want to try to add noise (1 or 2) using Photoshop "add noise". That 
should  fix the problem. It does for me in my color portraits when I do an 
extreme "soft focus" gaussian blur. If I don't add noise, I get gradient banding 
in the images.

Claude


[Non-text portions of this message have been removed]

>>... there is banding (with all curves) 
>> throuout the region of 70% (grey) to 100% (black)... the banding is 
>> in the form of uneven gradients (banding pattern varies between 
>> curves).  ...

>You might want to try to add noise (1 or 2) using Photoshop "add noise".
> That should  fix the problem. ...

Noise may fix such problems, but fine-tuning the curves might be a better
way.  The reality of any "canned" profile is that printers and inkset
batches vary slightly.  A certain percentage of printers, especially, seem
to be out on the ends of the bell curve sufficiently that the canned curves
are too far off.

I suspect with the UT7 or UT2 relatively neutral curves, tweaking the blue
curve will fix the problem.  I'm guessing that the curve that drops very
steeply to turn on the black ink is the problem.  Moving the exiting points
up or down, as indicated by printing a 21-step test curve, is what I'd try.
The 21-step ramp should show the same bumps that are in the photo.

Printing with no curves, using the "Color Controls," may also result in a
smooth ramp.  This is because there are no radical curves in the mix that
will magnify the printer variances.  If the "no curves" printing method
still shows bumps in the ramp, something else may be wrong.

Hopefully these wiggles in the ramp will not show up on too many systems,
but the reality of canned profiles or curves is that our relatively cheap
printers are amazing for the price -- but not perfectly consistent.

Paul
www.PaulRoark.com