Urgent Help Need_Indd cs banding problem

[rande]

We're having an Indd CS banding problem. Is there a quick way to solve that in Indd w/o re-building it in Photoshop.
I was wondering if anything in the Transparancy options helps.
isolate blend
k.o. group
or from the pull down menu.
multiply etc.

thanks if you can help

[gig0]

Can you be little more specific?

Is this with all jobs with gradients or just one in particular? If it's one job, what's the gradient desnsity values from the lightest to the darkest and over how many inches?

[rande]

Haven't had this problem in awhile. I think InddCS2 works better with them.

5.125" high
Linear 90?
0 _68.13(about 2/3rds down _ 100%
of
a green - c-35:m-0:y-60:k-5

[gig0]

Sorry if I don't understand;

so the dark values are c35 m0 y60 k5, right?

What are the values at the other end?

And what line screen is this imaging at?

[rande]

Right the dark color is 35/0/60/5
0-100%
150lpi

[gig0]

hmmm... the only banding I could understand would be on the black channel but it's only going from 0 to 5% so you shouldn't really see it.

Where do you see banding? On film, plate or proof? And whats the device?

[rande]

You can see it on the digital if you really look and on the proof sort of; but it comes out stronger on press.

[gig0]

Wow, theres just so many factors at this point I couldn't just give you a simple answer... just too many unknown variables. I know some rips can go out of whack with their curves *cough*Navigator*cough* because of a bad batch of plates and the curves are dependent on that along with chemistry and exposure scales. Does the rip need any calibration or exposure scales which you an check this stuff?

Theres also specific color combinations that could produce unwanted effects. I know back in the Brisque 3.0 days there were issues at a couple of places with moiré patterns with certain percentages of skintones and wood colors. A typical fix would be to output at higher than normal linescreen. Have you tried that or able to output at 175 lpi?

I don't know what rip you're using but some rips have settings in which you can modify how gradients are handled such as converting vector gradients to continuous tone or enhanced handling through postscript level 3. It's essentially the same as sending a photoshop gradient to the rip.

You also originally asked about transparencies. Does this job use transparencies? That could be a problem with some rips that use multiple resolutions when processing files. I've got a workaround for that too without going into photoshop. Let me know. I hope some of this helps.

[David]

What color are you seeing the banding in?

I'm reading this:

5.125" high
Linear 90?
0 _68.13(about 2/3rds down _ 100%
of a green - c-35:m-0:y-60:k-5

to be a 5 .125 " tall box with a grad (rotated 90 degrees) that has a midpoint at 68.13 with the darkest color to be the 35c,60y, 5k mix to zero at the bottom. Correct?

I just built one in CS and I can actually see the banding on my Mac screen. It looks like the color just drops off too quick. I'm seeing a hard edge just about one inch up from the zero point of the grad. It's like there's not enough color to carry that particular range.

Like this CS Grad:


Here's one done in CS2:

I don't see the hard edge on this one like in CS. It looks much better and smoother.
I couldn't find anything in CS that would make it smoother (as in transparency functions). I was able to add another point (just above the zero) that I put in a 2c, 2y in and it smoothed out the hard edge, but I still got the banding through the full range.
It may just be a CS thang... you may not have a choice but to re-do in PS or CS2.
sorry not much help,
David

[rande]

Thanks guys. CS2 was my next try this morning. I avoided it because of font issues. But I think you're right David I should just bring it into CS2 and mess witht fonts.