Agfa Advantage N-SL /Apogee X Moire problem

[buffnewskba]

Hello all -

I've recently run into a problem with our Agfa system. We recently switched to Apogee from a Harlequin Rip, and we've developed a severe moire issue, particularly in the mid-tones, mostly magenta and cyan.

Our setup previously was:
Agfa Advantage N-SL imager
Agfa VXCF 8 Processor
Agfa n94-vcf plates
harlequin Rip processing 2540 dpi and 175 line screen.

Current setup:
Same equipment, Apogee X rip.

We're getting the moire regardless of switching to 2400 or 1800 dpi, and the effects are not consistent between jobs. We can plate a job on all three resolutions, and today the 1800 may look best, tomorrow, the 2540.

Agfa is telling us that our imager is not capable of running 175 line screen, but we've been running 175 for three years with no issue.

Any help is appreciated!

 

[VladCanada]

AGFA told you 150 lpi maximum for conventional and XM screening, meaning moire-free ABS and Sublima.
You are waiting for the miracle coming from newspaper's designed machine.
Ok, say thanks to Punch Graphix and AGFA, if you were able to use 175 lpi without moire headache.
Today you made some steps away from AGFA prooven promisses.

If your car engine designed for high grade gas usage, and you fill up your tank with premium gas - do not complain for lower horse power output.

Try to use some HQ RIP features to minimize moire effects, all described in HQ user manual.

 

[dpig69]

175 lpi does seem aggressive for N94-VCF plates, but perhaps tweaking RIP settings will help. I'm not familiar with the Apogee RIP, but the Harlequin RIP is really good at running high line screens on lower resolution, with features like "Harlequin Precision Screening". I wonder if the Apogee RIP screen angles and frequency could be tweaked to what your pervious Harlequin RIP was giving you?

 

[gordo]

Moiré is a screen angle harmonic beat (conflict) issue. It is not a dpi/lpi nor an lpi vs the plate resolution issue. Agfa’s conventional (ABS) and their XM screening are identical as far as screen angles are concerned.
What screen angles are you using?
What kind of moiré are you experiencing - screen conflict (magenta/cyan...what are their angles), subject moiré, single channel, or?

gordo