Photo Production Presses

[PricelineNegotiator]

Hello,

I am in search of answers on how other printers deal with the conversion of RGB photos to CMYK. A lot of customers (and myself included) feel that the facial tones produced on our J75 are lacking, and overall look dark. I recently saw a piece from Minted, and I thought the images came out looking superb. I'm fairly certain that these types of printers are using Indigos (5000 and 7000 series), but are they using the extended gamut capability, or does the Indigo just have a better gamut with CMYK using the Electro Inks? I'd love to know.

 

[wonderings]

Are you letting your J75 do the conversion from RGB to CMYK? I find the Xerox digital presses do a terrible job and everything looks way to red in the faces when leaving it to the fiery to convert. Anything I create myself is always CMYK. Anything from a customer that is RGB I convert using Acrobat (convert to CMYK only SWOP). Makes a huge difference from my experience. It was like that on our old J75 and is like that on our Versant 2100, so I always do my converting before it gets to the RIP.

 

[PricelineNegotiator]

I am letting the EX RIP do the conversion. I just tried the profile you mentioned and I think it made a pretty good difference, but it still seems dark compared to what is on the screen. I'll keep you posted, but I'd like to know if these places like Minted are using CMYK or something else.

 

[Schnitzel]

It all boils down to whether you are using a color managed workflow or not: is your screen calibrated and profiled? Did you create ICC profiles for the various substrates you use on your press? If not, then matching the prints to the screen is practically impossible. Only when you have ICC profiles for the entire production chain, you can convert from RGB to the desired CMYK and preserve the intended colors.

Generally, Indigo presses try to conform to the ISO 12647 standard, so you can convert from RGB to a standard ICC profile (ISO Coated v2 or Fogra39) and get decent results, without having to build your own ICC profile. But for the best results, it is always better to build one (or more!).

 

[Puch]

Hi,

flesh tones are well within the gamut of most printers, J75 included. The difference you see can be a result of two main factors:

- a better calibration / profiling state maintained on the competitors' printers.

- some kind of active image processign before printing.

A good original (eg. an image from a midrange MILC or DSLR camera) must be of a very high quality using a properly color managed workflow. Try to grab a simple JPEG image from a camera, convert it using Photoshop to SWOP, then print that on any stock using SWOP as simulation color space. That should be very close to the image on screen, regarding flesh tones (given the display is calibrated / profiled).

We often use the Fiery to convert to CMYK (throwing PDF/X-4 onto the DFE, bypassin desktop separations at all) with spectacular results. The only thing to watch is to use APPE, and switch on "use embedded profiles".

 

[Schnitzel]

...convert it using Photoshop to SWOP, then print that on any stock using SWOP as simulation color space.

Why use SWOP? If you have a profile of the substrate already, just convert the image to that profile. If you don't have a profile of the substrate, then SWOP is meaningless unless the press conforms to that profile in the first place.

 

[PricelineNegotiator]

This is all good and dandy, but I'd like to know what each of these things mean, or, I need to learn more about color management in a comprehensive approach. Recommendations on where to start?

Edit: Your replies are greatly appreciated, and I understand the points you all have made. I feel it would have a greater effect upon our company for me to comprehensively learn about color management.

 

[Schnitzel]

Color management is not easy. To me it feels some times like black magic, most of the times like an interesting torture method. It also requires special equipment, time and the understanding that you'll be wasting a lot of prints in the beginning until you reach a decent level of proficiency. The problem with color management is that nobody can tell you what buttons to push - you need to learn what the buttons actually do and then apply this knowledge to every situation. This is why "just convert to SWOP" is basically wrong (even what I wrote about the Indigo machines works only in specific cases).

If your manager allows you to spend this time learning color management and purchasing the equipment, as opposed to hiring a professional, I recommend you start with "Real World Color Management" by Bruce Fraser, Chris Murphy and Fred Bunting. A bit outdated by now, but considered the best introduction to this topic. Good luck!

 

[Puch]

Why use SWOP? If you have a profile of the substrate already, just convert the image to that profile. If you don't have a profile of the substrate, then SWOP is meaningless unless the press conforms to that profile in the first place.

This is true in the offset printing business, but not in digital printing. DFEs attached to current Xerox, Ricoh and KM printers are normalizing all content to a common color space, before converting to the device color space. We use Fogra 39 as we're in the EU, but I guess in the States the default is SWOP. If you directly convert from RGB to the device color space, you need to switch off the normalization in the DFE, and IMHO it's a fairly advanced method. Mostly because you have to make sure that everything on the page is CMYK and is in the printer's custom color space.

Color management is not that difficult, if you follow the basic framework set up by Adobe applications upon installation. Not foolproof, but generally works well. If one can manage to export documents to PDF/X-4 before printing, using APPE on the DFE will guarantee a (mostly) flawless production.

 

[memador]

For professional photographic printing production with HP-Indigo we created a very good solution that includes color correction, smart image enhancement and ICC profiles for 4 (CMYK) or 6 (CMYK-LC-LM) colors, presently we are also testing a 7 color printing including LLK. It is a tool for producing over 2000 photos per hour provided that you are a good operator. If you use a calibrated monitor and recommended substrates the quality is superb, better than silver halide and the results 100% predictable. The basic package costs $3500, not cheap but having the volume it pays back within less than one month.
www.memador.net

 

[DannyB]

For professional photographic printing production with HP-Indigo we created a very good solution that includes color correction, smart image enhancement and ICC profiles for 4 (CMYK) or 6 (CMYK-LC-LM) colors, presently we are also testing a 7 color printing including LLK. It is a tool for producing over 2000 photos per hour provided that you are a good operator. If you use a calibrated monitor and recommended substrates the quality is superb, better than silver halide and the results 100% predictable. The basic package costs $3500, not cheap but having the volume it pays back within less than one month.
www.memador.net

My company does photographs and we still use silver halide. We use indigo to print books and have looked at it for photos but the problem we run into is they don't have a substrate that mimics photopaper well enough. What has your company done for this or do you not concern yourselves with matching photopaper?

 

[DannyB]

Hello,

I am in search of answers on how other printers deal with the conversion of RGB photos to CMYK. A lot of customers (and myself included) feel that the facial tones produced on our J75 are lacking, and overall look dark. I recently saw a piece from Minted, and I thought the images came out looking superb. I'm fairly certain that these types of printers are using Indigos (5000 and 7000 series), but are they using the extended gamut capability, or does the Indigo just have a better gamut with CMYK using the Electro Inks? I'd love to know.

I am an operator on a Indigo 7500 and we also have a J75. I am by no means an expert when it comes to prepress. But i can tell you that out of the box the indigo is going to print a lot cleaner than the j75. As far as I know we use the same process to send to the indigo as we do to the j75 and the indigo is always better. We originally purchased the J75 with the thought that we could use it to print envelopes and flyers which we do on smaller xeroxs. But also to print books which we do on the indigo. That did not happen the J75 just can not match the indigo so now we have a giant envelope printer.

 

[PricelineNegotiator]

What type of envelopes are you printing through your J75? Are you feeding flap out through the bypass, or flap in through tray 6 with the envelope bracket?

 

[DannyB]

What type of envelopes are you printing through your J75? Are you feeding flap out through the bypass, or flap in through tray 6 with the envelope bracket?

We do 8 1/2 x 14" flap out through the bypass

 

[DJimenez]

Minted is ran on this HP http://h20195.www2.hp.com/V2/GetPDF.aspx/4AA3-6493ENW.pdf

 

[Nashy]

My company does photographs and we still use silver halide. We use indigo to print books and have looked at it for photos but the problem we run into is they don't have a substrate that mimics photopaper well enough. What has your company done for this or do you not concern yourselves with matching photopaper?

Try E-photo lustre from Felix Schoeller. Been using this to print photobooks on 7000 series for years.

 

[lfelton]

"Nice" reproduction of skin tones is a mine field and you do have to be careful not to conflate different issues. Provided you ordered the right RIP and necessary options, accurate colour profiling of your press is a skill your press vendor should be able to competently teach you. It's pretty straightforward and profiling a new paper should take minutes for a competent operator, certainly less than an hour. Assuming you have a well managed pre-press workflow, that gives you a good base line. However, calibration is another matter, some machines are easy, some you struggle to ever keep in a stable calibration. When reproducing something like skin (cloudy skies are another notoriously difficult area to always get right), a tiny mis-calibration can produce unwanted artefacts. Unfortunately there are also characteristics of the print engine to take into consideration. Both the Versant 2100 and iGen5 have a noticeable "grain" when reproducing some of the trickier pictures. This can have the effect of making the image look darker in places, even with accurate profiling and calibration. If you look at the picture in isolation, 90% of people would consider it just fine. However, compared side by side with a print engine that doesn't exhibit this issue (say an Indigo 7500), just about everyone can tell a difference. We've done blind testing on sample photobooks from the different engines (most manufacturers), so that is empirical, not anecdotal.

So, in summary, to fix your issue, you need to accurately identify where the issue lies and even then, it may be a "feature" of the print engine.

Incidentally, I still have no idea why people would ever recommend using a SWOP profile as part of a workflow for sheet fed digital presses. I'm no expert, but why would you start from using Specifications for Web Offset Publications (SWOP)?

 

[memador]

My company does photographs and we still use silver halide. We use indigo to print books and have looked at it for photos but the problem we run into is they don't have a substrate that mimics photopaper well enough. What has your company done for this or do you not concern yourselves with matching photopaper?

Most of our customers print on either Felix Schoeller E photo paper and another great solution is printing on regular coated paper and laminate with a GMP texturing laminator. Specially the last one emulates silver halide perfectly. The profiles built in our program take on account this process.

 

[DannyB]

Most of our customers print on either Felix Schoeller E photo paper and another great solution is printing on regular coated paper and laminate with a GMP texturing laminator. Specially the last one emulates silver halide perfectly. The profiles built in our program take on account this process.

I guess the owner is just to stuck on halide because I talked to upper management and we have already tried the avenues that you and Nashy mentioned and they just don't like it. So I guess we will stick with halide until it is not available anymore. Which is not a huge surprise they did the same thing with film they did not switch to digital until they literally could not buy film anymore.