characteristic curves

Hi im running a sm52 4 color 2005 plus a 74 cd 6 2005 with cp 2000.I was wondering about the characteristic curves .Mostly they are set fine and working well but i still dont completly understand what im adjusting. The manual is pretty vague.My main ? is what does the zx z1 z2 do when you adjust them .Also when trying to select a curve for special spot color most of the time i cant change it .Its greyed out.

 

no help yet . so anybody know another forum i maybe able get feed back on this.

 

JMT, I was trying my curves and can't figure why your special is greyed out. Make sure you have a curve for a special selected for use, indicated by the green dot. The only curves that cannot be adjusted are Heidelberg curves for process colours (those can be copied and then changed). I can't recall what the ZX are indicators of. When I adjust mine I make adjustments to each of the percentage zones or just a specific zone where I notice a problem.

 

Hello guys!

Thanks for the informative information and What is the definition of a characteristic curve in photography?Can any one give some idea....


Toner Cartridge

 

Curves

Hi,
The zx, z1 etc are the speed as a percentage that the fountain roller turns at.
zx is variable, z1 is 30% (i think) and z2 is 70%. At least i'm pretty sure thats what it means.
The horizontal line shows the % of image area and the amount of diode (ink key opening) it requires to ink that area. For example 5% image area may require 10 micro openings whereas 100% may require 233. I am experimenting at the moment and so am still trying to get my head ariund how it works but will relay any info I come across to you.
Hope this helps!

 

Hello guys

Characteristic curves show how many diodas are opened at diferent coverage of the plate from 0%,1%, 5%,10% ....70% and 100%. For example 1% is just color bar in one zone and 100% full tone. And if you are useing Prepress interface you can see at diferent coverage of the plate how are ink zones are opened. So if you you start a job and in some zones of coverage of 40% you density is to high you should lover the number of diodas in curves at 40%. From the expirience the number of diodes should be rised on 0%,1%,5%,10% for around 15 to 20 %. If you are not useing Prepress interface then it is a little more hard to get the right numbers, because at prepress interface
you are always getting the same numbers and if not every printer opens different zones then second printer.

Regards Borut

 

RJ Litho

Be careful we you adjust these curves they are base on speed.The ink profiles will change as you speed up your press It can cause you some major color variation if not set right ..The Heidelberg set curve usually works very well. Last thing you want is to have to opposite shift changing these setting's. There is a charateristic curve for water and for the coating unit also. You can build you own curve an save them.when you set up a job you just choose the one you want .

 

thanks alot mr tw and borut this info helped alot.

 

Whats the general base line curve to use Im new to speedmasters But we have problems holding colour From a zip3 file it looks ok But when we start running the colour drops Is this caused by an incorrect curve setting Also damp is hard to settle Any help gladly taken

 

Hi there I need some help. We have 2 speed masters 102 and on one when we transfer the job from prinect it shows that all the keys on the console are closed but on the other press they are fine. please help

 

Hey Oceanview, The only thing I can think of is you have selected a set of curves which may have been created but not adjusted. The Heidelberg curves should still be available to you (they can never be changed-they can be copied and then altered to your press). Enter the characteristic curves page, there may be a few options of curves available. If the green dot is not beside the Heidelberg curve, press the green dot button on the bottom of the screen then select the Heidelberg curve. The green dot should be beside the Heidelberg curve. Pull up a scan and see if you have any fountain settings. Good luck.

 

I will give this a shot. I really appreciate your time ,help and knowledge. Thank you so much Grant B.

 

Oceanview, Just wanted to add another thought, and it's only a double check. After allocating colours to the specific units, ensure that the units you have designated with colour have been selected for use in the unit selection page. Basic I know, but it's worth the double check.

 

Yes, thanks again Grant B. I'll double check on that too.

 

Hey Oceanview, I was wondering if you got your curve issue sorted out.

 

Hi Grant B, no I haven't had a chance. I've been out of the shop and I won't be back till Tuesday but I'll keep you posted. Thanks again for everything.