Evo Color Managment

[irreality]

So i believe im a little lost... or maybe i just need some reinforcement of my own thoughts.

What I want to do is have my proofs output the same machine on one as the other. As we are planning on phasing out one of the pieces of equipment.

I am under the impression that this conversion can be done through a process template in evo, most particularily the Match Colors tab. Utilizing ICC profiles for the devices.

Now.... this is where im getting confused i believe.

In the color matching pool ...

I have "assign source or devicelink profiles" (I believe this is the one that im supposed to be migrating the color to - so the condition of what needs to be output- Ie the icc profile of the old printer)

I have the "convert to destination profile" aka Proof Profile (this would be the icc profile of either the Proofer itself or the standardized profile - ex. Swop. or A self made profile from the proofer itself)

But i think im mixing something up here. as something just doesnt seem right.

Any takers want to point me in the right direction ?

 

[Stephen Marsh]

What I want to do is have my proofs output the same machine on one as the other. As we are planning on phasing out one of the pieces of equipment.

Do you have a RIP driving each machine?

Do you calibrate each machine using a spectro to a similar average and max. dE value?

Are both machines using the same proofing media, simulation/target/aimpoint, profiles, colour settings etc?

Even with all of the above, one device may not exactly match another. You may then need to simulate one device's output on another.

I am under the impression that this conversion can be done through a process template in evo, most particularily the Match Colors tab. Utilizing ICC profiles for the devices.

That is one small part of the story, see my previous comments for some of the other factors.


Stephen Marsh

 

[irreality]

Yes there is a rip driving the machine. EVO is a rip - it also has a KPS driving the machines themselves.

They are calibrated using a spectro weekly

That is my goal - to simulate one on the other (yes i know it wont be exact).


What im looking for is specifics about what each of the sections means/does in the color matching tab in EVO. And what would i place in each of them to get the best simulation.

Thanks.

 

[Stephen Marsh]

Hi irreality, I understand that you specifically wish to have info on Evo colour settings - however that is pointless unless everything else is correctly in place.

I don't use Evo and have more interaction with Connect. Just to confirm, which process template are you editing? Refine, loose page or imposition?

If loose page or imposition, are you using the KPS Direct Connection method?


Stephen Marsh

 

[rich apollo]

I have "assign source or devicelink profiles" (I believe this is the one that im supposed to be migrating the color to - so the condition of what needs to be output- Ie the icc profile of the old printer)

The "source profile" is the colorspace that your file is in. This will be where you plug in a profile of a standardized printing condition (GRACoL, SWOP, FOGRA), or your custom press profile.

I have the "convert to destination profile" aka Proof Profile (this would be the icc profile of either the Proofer itself or the standardized profile - ex. Swop. or A self made profile from the proofer itself)

The "destination profile" will be the profile of your proofer.

 

[Stephen Marsh]

Assuming a loose page or imposition process template, the following are the key options on each tab/section:

* Ouput to: Kodak Proofer (KPS direct connection)

* Device: Select the proofer

* Layout: Select the KPS media config, KPS layout and or other desired settings

* Render: APPE or CPSI RIP option (usually APPE)

* Match Colours: Input device - As defined below. Then set a simulation profile (Fogra 39, GRACoL, SWOP etc) or simulation devicelink profile (GRACoL SM240 720x1440, F39 SM190 720x720 etc). Use a devicelink profile for the reference printing simulation and the proofer media configuration if available. Select Raster Overprint Handling method.

* Match Colours: Convert to Destination - Select the proofer profile for the media configuration previously selected on the layout tab

* Match Colours: Spot Colour Handling - Select user, factory and or recipe from file as required

I don't think that you will need to set an assigned profile for proofing, as the refine process template would be converting any incoming RGB and or perhaps CMYK to the correct profile way before proofing. When proofing, the source/assigned profile is then assumed to be the same as used in Match colours/Input device.

For example, let's say that you have two proofers:

Proofer A - Epson 7880, set to simulate GRACoL on Kodak SM190 media at 720x720 dpi
Proofer B - Epson 9900, set to simulate GRACoL on Kodak SM240 media at 1440x720 dpi

Both printer's are set to simulate the same reference/target print condition - GRACoL. In theory, "it does not matter" that they use different printers, with different inks, with different paper at different output resolutions. As both printer's media configurations are being calibrated at the KPS Matchprint Inkjet RIP, both should output very similar simulations of the GRACoL reference/target. Of course in practice, there will be differences based on the limitations of the hardware, inksets, media and resolution.

In theory, there should be no need to simulate one printer's output on the other, as both proofers are set to simulate the same target/reference anyway - GRACoL. As long as both printer's media configurations are being calibrated to similar "tight" dE values, then the output of each printer should be as close to the target as possible (and thus close to each other, within physical limitations).

In practice, sometimes there will still be differences. Some small, some larger for different colours. The differences between both printers may well be within dE tolerance for the target condition and may well be smaller than the final press variation to a proof. Generally it is accepted that as long as both proofers are proofing to GRACoL within tolerance, any difference between both proofers is acceptable... That being said, sometimes the goal may be for Proofer A to be a closer match to Proofer B (or vice versa). If this is the case, one has to build a simulation devicelink profile to mimic the output of one proofer's GRACoL on the other proofer. Now the goal is to make one proofer appear to look like another different proofer that is simulating GRACoL. The idea is that one proofer should print like the other and that both should still be accurately simulating GRACoL. This is not impossible, with the right tools it is fairly easy - however it is not as simple to setup as simply simulating a common target reference condition on the two separate proofers.

Hope this helps,


Stephen Marsh

 

[irreality]

Thanks for your help guys... You reinforced what i had originally believed (until i got into the mess of color management that They have set up here. Its really just a cluster####. They have alot of high end equipment, that was just never set up correctly... for YEARS (ive been told that nobody has understood color management in here for some time) ... now what people have been seeing coming out of these machines - has been a deemed a standard (incorrect mind you).

But now Trying to align the output of the old Kodak approval (as we are trying to phase it out), With the epsons has become a mess. As profiles were just thrown in for whatever people thought was correct. Messed up device link profiles that the epson doesnt like. ugh....

I believe the best way to get the results that im looking for would be to output a target on the Kodak, create an icc profile for it specifically (utilizing the exsisting conditions). and plop it into the input device for the epson....

Let me know if that lines up with what we've been talking about. I appreciate your time.

 

[Stephen Marsh]

Yes, I have done this before. Output a Kodak ColorFlow chart on an Approval to capture that particular device condition (laminated to a specific substrate, press simulation, lay down, donor set etc). Then measured the chart into ColorFlow, then created a devicelink profile connecting the Approval simulation to the intended inkjet profile media/resolution.

I don't think that I still have the ColorFlow reports, however in the booth both sets of output looked very, very close (apart from one being halftone and the other "contone").


Stephen Marsh

 

[irreality]

Thanks for your help Stephen, You have been extremely informative.

I wish i had colorflow :-/.... Unfortunately All we have is an old copy of profile wizard, it would do the trick.... However, The original software / dongle combo that was purchased was a Scitex Product, since then that company has changed hands multiple times. And Even though I have the dongle and box of the software... the hardware key is nowhere to be found. I even have the original Reciepts lol... and Kodak is trying, but they cant seem to find any documentation to back it up, nor the hardware key...

I guess I may be in the market soon for some profiling software.

 

[Stephen Marsh]

irreality, talk to Kodak as you have two or three options:

1. Purchase the creation of the devicelink profile/s as a colour service. This will likely get too expensive to justify after the first couple of profiles.

2. Do you use Kodak Matchprint inkjet media or third party media? What version number and or level of Kodak Proofing Software do you use (basic, commercial or packaging)? Depending on the answers to these questions, it may be possible to use KPS to create a devicelink profile.

3. The [basic] ColorFlow (use but not create profiles, dvl, curves) and the full featured ColorFlow Pro are only available to Prinergy, not stand alone. You may or may not not be able to justify the purchase of ColorFlow Pro, despite what it can do for your company as a colour relationship management tool, aligning the colour of different devices. That being said, there is another option. There is a special "dumbed down" version of ColorFlow for KPS. This allows you to create device profiles and devicelink profiles for Kodak Approval KPS or Matchprint Inkjet KPS (no curves and seamless workflow integration). The ColorFlow KPS version would be a smaller purchase price when compared to the full workflow version. Of course, it also helps if you have an automated spectro to read the characterisation charts output on the Approval (i1iO table, i1isis etc).

Of course, you don't have to use ColorFlow and you don't have to have a devicelink profile. The beauty of a ColorFlow devicelink simulation profile for inkjet proofing is that you can link the source colour to the inkjet destination profile using absolute colorimetric intent while at the same time editing the devicelink profile white point to remove the paper white simulation. This way you can have your cake and eat it too - best colour for inkjet proofing (abs col), while not being stuck with the abs col paper white rendering. Without a devicelink, you could just have a two profile approach using input and output profiles, probably using rel col intent if you did not wish to simulate the source paper white.


Stephen Marsh