KM 6501 - Fiery - colour has never been right ?

[natty]

Hi,

We currently have a 6501 and are looking to put in another shortly.

In the 12 months or so we have had our current machine the colour has never been quite right.

There has been a magenta cast to everything (we calibrate regularly) infact the only time there isn't a magenta cast is when it is not calibrated.

Through a 3 colour grey (C 40% M 50% Y 60%) at it and it ALWAYS looks red.

We also have a problem with printing blacks and the only workaround is to turn off the colour profiling completely)

My question is, what colour settings are you running to get as close as possible to a litho (lets say FOGRA)

I have tried everything and it is just never right.

Can we fingerprint the press in some way ?

My concern is when we put in the second machine it may be different again ?

[JoshB]

Well, I always find it's easier to get help when you're about to buy something, so you've got that going for you. Bring up your concern and insist that before you can purchase another press you've got to resolve the off-color issue and see consistent results between the machine on your floor and the demo machine on theirs.

My thoughts on where to start looking for troubleshooting would be:

#1 - Try different papers. Maybe there's something about the paper you are using that's ruining your calibration?

#2 - If you get this trouble consistently on multiple papers, what about checking your profiler? The profiler itself can be off or damaged. Borrow one from your dealer's demo floor.

[Mike Bishop]

I have had a KM 6501 C for about 10 months and I have the exact same issues. My RIP tower is labeled as a PRO 80, but I know that even the techs have had trouble determining exactly what version of the RIP it is. This RIP has incorrectly handled Spot colors and RGB files since it was installed. If I send a file over that has a solid spot color rectangular header with swirls made out of tints of the same spot color; the color in general and the swirls in particular look incredibly far off from the color they should be matching. This type of terrible color matching also occurs when the RIP is fed an RGB file. I have had reps from the company that sold us the product as well as Fiery on site to try to solve the problem, but the issue has never been resolved. I have simply been given "workarounds" that are inexact, time consuming and only serve to show that the product can not handle simple color conversion in the RIP.
I too have noticed at times that after calibrating the machine the color actually gets worse. I just did a job with a light blue sky in the background that became pink and purple after I calibrated for the run. Sometimes the color gets better as it gets further out of calibration.
It seems that the Konica can lay down decent color, but that it gets fed bad data from the RIP. Of course if these companies are selling the products as complimentary they should both work towards solving these issues. This pairing of 6501 and Fiery is not a mature, efficient product. There are real problems with this pairing that can not be solved by the companies own reps.

[Greg_Firestone]

Is the color consistently off after calibration, e.g. is it always too magenta or too yellow, or does it vary? If there's no consistently at all, your out of luck no matter what steps you try to do. If you can at least get it to a consistent (yet incorrect) point, you might have a chance.

Greg

[Emtri]

Hi,

Through a 3 colour grey (C 40% M 50% Y 60%) at it and it ALWAYS looks red.

We also have a problem with printing blacks and the only workaround is to turn off the colour profiling completely)

My question is, what colour settings are you running to get as close as possible to a litho (lets say FOGRA)

Can we fingerprint the press in some way ?

1: The 6500/6501 has always had problems doing 3 colour greys as well as large light multi channel solids. If and where possible let your rip handle it as black only, often this will look better.

2: What sort of black issues are you having?

3: We generally run SWOP for our konica

4: Yes. Konica does sell a color profiling suit that allows you do build ICC profiles for you machine, this may be handy if you are running two machines, that way they can be matched.

Also what controller/rip are you running on your 6501?

[Correct Color]

There's always an answer.

The problem is finding someone who can sort of what it is, what's causing it, and how to correct it.

And unfortunately, all too often, whomever that person might be, they don't work for whomever it is you have available on your list of people to call to solve the problem.

We also have a problem with printing blacks and the only workaround is to turn off the colour profiling completely)

Then that would indicate that your profiles are most likely the problem. They certainly could cause just the issue you're describing. If your device profiles are off in relationship to your machine in a calibrated state, it's certainly possible they'd create just the effect you describe. And if others have the same issue then it sure sounds to me like the stock profiles for that machine just might be bad.

Can we fingerprint the press in some way ?

It's what I do for a living.


Mike Adams
Correct Color

[jotterpinky]

Our new printer KM 6000 also has the same problem. I've noticed most printers have a tendency towards one or the other color. The other Xerox printers I've owned have had either a pinkish (magenta) hue or a yellow hue as is the case with our 700.

The current Konica has always been pink but will not print a good red color, everything looks orange especially when compared with output from our Xerox.

We've calibrated to no avail, and even went as far as creating profiles to feed the rip for different paper types we commonly use. Rather than get us truer color this only served to make the color even further off from what we see on our offset presses despite having created profiles for the presses themselves and having our copiers simulate the color from the press. In my experience there is no magic bullet with color on these type of devices as they seem to vary widely even with regular calibration.

We have a brown color we run quite often for a chocolate company on our digital equipment and have taken to calibrating just before running it each time. Despite this the color of browns NEVER match without tweaking...seems as though the calibration does next to nothing as far as preserving consistency.

What I find hilarious is that our technician seems to think that calibration will fix a whole host of problems. One time we had a "greenish" bar printing at the head of every sheet for about two inches then it disappeared further down the sheet. His first thought was to "calibrate" to get rid of it. It's stupidity like this line of thinking that is the real problem with many of these independent dealers who know next to nothing about color or calibration. I think you are victim to one of these dealers as are many of us.

[Robbie101]

This is prolly a stupid question but have u gone under adjustment and knocked the magenta out.
-31 or invalid.

[natty]

Is the color consistently off after calibration, e.g. is it always too magenta or too yellow, or does it vary? If there's no consistently at all, your out of luck no matter what steps you try to do. If you can at least get it to a consistent (yet incorrect) point, you might have a chance.

Greg

Yes its fairly consistently wrong after calibration. Always too red.

I think as stated its what the profiles are doing which is the problem... If you just turn off the profiles it prints as a press should. Bearing in mind that of course the CMY colour of the toners doesn't match offset ink colour, which i guess is why they try to profile it to compensate, But the way the profiles are implemented is just wrong.

For instance, i guess they figured that for 100% cyan the konica produces naturally they needed to add some magenta to match offset ink, which is fair enough, but i have laid down 5% screens of cyan before and with the profiling on, you can visibly see magenta dots with the naked eye... Surely at such a low density there would be no need to add ANY magenta ?

[natty]

2: What sort of black issues are you having?

Well, the profiles seem to interpret images differently to vector art.

When you through for instance a file with a solid black vector background that has an image which has been flattened (say there is a drop shadow that has been flattened to an image in the middle of the black), the rip prints the vector black as pure 100%, but prints the black that is part of the image as 4 colour black, so we get this noticable box.

Turn the profiling off and it prints exactly as it should.

Roll the eyedropper over it in pitstop and the flattened black part of the image is 100% (which of course it should be it its just been flattened) ... But again its the way the profiles behave which breaks everything !@@!