Digital BW, The Print

I know that this problem has been discussed much before but I am 
struggling and need some input.
This is about an Epson 10600 using Cone K6 inks. There is one image 
made from a Leica M9 raw file that has banding issues in the sky. It 
is a smooth dark gray (image is now black and  white), darker at the 
top of the frame, lightening as it moves into the image.
I have tried: head cleaning, alignment checks. rotating the image 
180, rotating the image and printing on roll stock so I can have the 
image horizontal. In all cases, nothing has affected it. The banding 
continues in the direction of the head movement.
It is not detectable in the other areas of the image but shows 
clearly in the sky.
I have printed this image on a 7880 through ImagePrint and it is perfect.
I really would appreciate some suggestions as to how to try and 
correct this problem.
All ideas and suggestions will be studied.
Thanks,
Paul

-- 
Paul Kohl
Visiting Professor
Art, Design and Media
Nanyang Technological University
Singapore

Hi Paul,

What rip/driver are you using to print with these inks?

I have used this same configuration for years and have never experienced banding like that, after I slowed my printer down in the menu.

My fist thought IF you have clean nozzles is to take your ink carts out and shake them to make sure the suspension of pigments is ok if you haven't had troubles before. All pigment settle if you don't do this. Then do a few head cleanings to flush the lines out.

Alignment is very important also.

My second thought is to relinearize your set up. Printers do drift over time.

Personally I use Studio Print rip for this set up and I relinearize about every 6 months or so. Different papers require their own linearization also.

As a test you may try running this file through your system as an RGB file through the standard Epson driver to see if you still see this banding. If not you know it has something to do with your rip set up and subsequent linearization. QTR curve or whatever other driver curve you are using could be your issue .

Finally there is a way to go into the 10K printer menu and slow your printer down to what I believe is called 8 pass printing that improves quality (4 pass is the standard but not as precise). I do this on mine as a standard procedure. I had some banding initially on the slower print setting. But I'm using SP with Smooth Diffusion dither. That setting did it for me.

Of course never use Bi Directional printing with the 10K, only 1440 UNI.

john



--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Paul Kohl <pkohl@...> wrote:

>
> I know that this problem has been discussed much before but I am 
> struggling and need some input.
> This is about an Epson 10600 using Cone K6 inks. There is one image 
> made from a Leica M9 raw file that has banding issues in the sky. It 
> is a smooth dark gray (image is now black and  white), darker at the 
> top of the frame, lightening as it moves into the image.
> I have tried: head cleaning, alignment checks. rotating the image 
> 180, rotating the image and printing on roll stock so I can have the 
> image horizontal. In all cases, nothing has affected it. The banding 
> continues in the direction of the head movement.
> It is not detectable in the other areas of the image but shows 
> clearly in the sky.
> I have printed this image on a 7880 through ImagePrint and it is perfect.
> I really would appreciate some suggestions as to how to try and 
> correct this problem.
> All ideas and suggestions will be studied.
> Thanks,
> Paul
> 
> -- 
> Paul Kohl
> Visiting Professor
> Art, Design and Media
> Nanyang Technological University
> Singapore
>

Paul, I would join and ask here-
http://tech.groups.yahoo.com/group/piezography3000/
and request membership and ask here-
http://tech.groups.yahoo.com/group/piezobwpro/
for access to more users with setups similar to yours. Also, you might try a paper advance adjustment as well. But I hate to give you more work to do that may result in nothing...
Tyler

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Paul Kohl <pkohl@...> wrote:

>
> I know that this problem has been discussed much before but I am 
> struggling and need some input.
> This is about an Epson 10600 using Cone K6 inks. There is one image 
> made from a Leica M9 raw file that has banding issues in the sky. It 
> is a smooth dark gray (image is now black and  white), darker at the 
> top of the frame, lightening as it moves into the image.
> I have tried: head cleaning, alignment checks. rotating the image 
> 180, rotating the image and printing on roll stock so I can have the 
> image horizontal. In all cases, nothing has affected it. The banding 
> continues in the direction of the head movement.
> It is not detectable in the other areas of the image but shows 
> clearly in the sky.
> I have printed this image on a 7880 through ImagePrint and it is perfect.
> I really would appreciate some suggestions as to how to try and 
> correct this problem.
> All ideas and suggestions will be studied.
> Thanks,
> Paul
> 
> -- 
> Paul Kohl
> Visiting Professor
> Art, Design and Media
> Nanyang Technological University
> Singapore
>

Try viewing the image at the pixel level and slowly pan through the cloud, making note of the exact pixel colors as you go. You may find that the image itself has banding -- unseen on a normal-sized screen image -- where the pixels colors show large leaps, as you scroll down. This can happen when the visual graduation of the cloud is more subtle than your processing program can handle. An easier way to check this is to add a bit of noise to the cloud on a copy before you try another print. 

Banding of this kind is more common than you might think, and has nothing to do with the printer.
 
Alan Scharf
Saskatoon
ascharf@...


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

John,
Thanks for the suggestions. I will try them. I am using StudioPrint, 
as you do/did. In fact, you were very helpful in getting this whole 
thing going some months back. I used the jpeg images you posted to 
clean and empty the original carts before refilling them with Cone 
inks. Thanks for all that help, by the way.
So, I will try and see what's what.
If I run this image through Photoshop as an RGB image using the black 
ink setup I have, will that tell me anything? I will try and see.
Paul

-- 
Paul Kohl
Visiting Professor, Photography
Nanyang Technological University
Singapore

RGb - What it will tell you if your banding is being created by Studio Print settings or linearization drifting, or an issue with your printer. That is the fist place to start.

SP uses less ink and offers a better dmax but it also requires a more precise output curve. Like I said you may need to relinearize SP. 

Finally, there is a printer "quality" slider available in SP that can be changed for problem printers. One option you have is to move that slider up to say 30 or so if you really have to. The more you move that slider the more grainy the output becomes, but using around 30 will not effect your resolution very much if any.

First step is to shake your ink carts, run some ink through it and relinearize. SP is cumulative so I would do three sets of patches before you work that quality control slider if possible. Your right though, if any banding is evident it will show up in large areas of continuous tone, like a sky.

Try slowing your printer down to 8 pass ( read the manual to do that). That alone will most likely solve your problem. This is still a pretty fast printer, even at 8 pass and that always increases quality.

john

j

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Paul Kohl <pkohl@...> wrote:

>
> John,
> Thanks for the suggestions. I will try them. I am using StudioPrint, 
> as you do/did. In fact, you were very helpful in getting this whole 
> thing going some months back. I used the jpeg images you posted to 
> clean and empty the original carts before refilling them with Cone 
> inks. Thanks for all that help, by the way.
> So, I will try and see what's what.
> If I run this image through Photoshop as an RGB image using the black 
> ink setup I have, will that tell me anything? I will try and see.
> Paul
> 
> -- 
> Paul Kohl
> Visiting Professor, Photography
> Nanyang Technological University
> Singapore
>