Moire pattern with Dolev 800V2 and Xitron RIP

[mercury_173]

I just bought a refurbished Dolev 800V2 imagesetter with Xitron RIP. I observe moire patterns when it runs at 24,000 rpm and low resolution. For Xitron Rip I already turn on the HPS and set grey level up to 4096 in page set up but can not eliminate the pattern. The moire pattern only go away when it runs at lower speed around 17,000 rpm and higher resolution.

Any ideas of what could be the problems and how to fix it?
Really appreciate your help.

Will

[minhhieucn]

Can you tell me where did u buy this Dolve 800v2? Thank you for your help.