Spot color .pdf to spot channels in Photoshop?

[MJNC]

(in my frustration I first posted this to the Color Management forum; please forgive my duplicity...)

Hey all you PrintPlanet co-inhabitants.
I have a .pdf created with pms colors in illustrator. Problem is, when I open the .pdf in Photoshop, everything converts to one of the Photoshop presets (CMYK, RGB, etc.).
How do I get my Illustrator file to make photoshop open the .pdf in spot color channels? Is there even a way (short of a rebuilding the whole thing as grayscale>multichannel>select one color at a time and move to new channel process)? I know this is the way it used to be back in the day before Adobe Creative Suite. Since the major .pdf movement (headed-up by Adobe!!) you would think I could open my spot .pdf to spot channels in Photoshop on the fly.
Somebody help me please...? I am about to go insane! (Well, only slightly-which is normal, but you get the point).
Thank you in advance for whatever help you can send my way.
Peace!!
_m

 

[leonardr]

I have a .pdf created with pms colors in illustrator. Problem is, when I open the .pdf in Photoshop, everything converts to one of the Photoshop presets (CMYK, RGB, etc.).
How do I get my Illustrator file to make photoshop open the .pdf in spot color channels?

Why would you want to take a healthy happy PDF file and RASTERIZE IT in Photoshop????

 

[CHM]

Why would you want to take a healthy happy PDF file and RASTERIZE IT in Photoshop????

The same question popsup here, why convert a good Vector pdf into pixels?

 

[Lukas Engqvist]

If you want to limit the number of colours I'd do it in Illustrator.
Check out live colour function, it rocks

 

[MJNC]

Spot color .pdf to spot color channels in PhotoShop...

Spot color .pdf to spot color channels in PhotoShop...

Hey people of the PrintPlanet;
I would never take beautiful vector art and screw it up by converting to pixels!!!! I so agree!
Here’s the situation. My boss sent me the .pdf via email so I could go over it for him. He’s running only PhotoShop on his office PC way on the other side of a huge warehouse. So I open the .pdf in Illustrator and tell him that it has been set up as a spot color job. At the same time he opens another copy of the same .pdf in PhotoShop in his office and wonders why the spot color information does not show when he uses the color picker/eye dropper. I was just hoping that I could give him a real answer based on fact, as opposed to telling him that no one with any experience uses PhotoShop to view .pdfs.
I have to make sure he has acrobat reader - I know the seps maintain in the print dialog.
Still any clues would be a big help.
Thanks to you All!!!
_m

 

[bean66]

Take away his Photoshop and get him Acrobat.

 

[claude72]

Why would you want to take a healthy happy PDF file and RASTERIZE IT in Photoshop????

Sorry, but "rasterize" is not the good word!

Opening a vector file (PDF or EPS) in Photoshop will PIXELLIZE (not rasterize) the datas, transforming all the vectors in contone pixels (grayscales or colors) at the resolution specified in the pixellization dialog box of Photoshop.

To make a rasterization, you need a RIP, that will transform all the :
- black vectors in black pixels, at a given resolution,
- gray vectors and grayscales pictures in black screens,
- colors vectors and pictures in separated CMYK screens,
and then:
- built the screens at a given screen ruling with black pixels, at the same resolution,
- and assemble all that black pixels and the pixels of the screen dots in one 1-bit picture for each separation,.


Shortly said:

• pixellization asks the user for a resolution, and outputs ONE CONTONE picture,

• rasterization asks the user for a resolution and a screen ruling, and outputs as many 1-bit pictures as there are colors to be printed (1 in black and white, 4 in CMYK, and one for each spot-color)

 

[mschilling]

Well, Photoshop on my screen says "Rasterizing File" when I open a composite pdf, so that's pretty clear what's happening. You get a chance to pick your color space, RGB, or CMYK, your choice, no spot colors, typical of Photoshop. If you can produce a separated pdf from your file, then that can be opened in Photoshop, one color at a time as grayscale images, although it can be tough to tell one color from the next. Obviously, Acrobat is the normal way to check color breaks in files.

 

[claude72]

Well, Photoshop on my screen says "Rasterizing File" when I open a composite pdf, so that's pretty clear what's happening.

Purhaps that your Photoshop says "Rasterizing File", but it's a mistake: that's not a "rasterization", but a "pixellization"... and that's really very different!!!

And for the same action, my Photoshop says "Pixellisation du fichier", which is the correct name for this action!

 

[leonardr]

Sorry, but "rasterize" is not the good word!

Opening a vector file (PDF or EPS) in Photoshop will PIXELLIZE (not rasterize) the datas, transforming all the vectors in contone pixels (grayscales or colors) at the resolution specified in the pixellization dialog box of Photoshop.

I have to say that in my 20+ years of doing computer software, I have NEVER heard the term "pixellize", at least in English. I've never heard it said, seen it in a software product, etc. What you describe above is the process of "rasterization" - conversion of a vector-based format into a raster-based format (hence the term "raster-ization").

 

[beermonster]

agreed

i understand and see where you are coming from calude bit it is just a "name"

it is known as rasterization, both in photoshop and a RIP - but its just a name - no issue - we all KNOW what's going on.

like someone said - get that guy off photoshop and buy a copy of acrobat - there must be old versions kicking about somewhere........•cough ebay cough•

i have always wanted photoshop to be able to open any spot file into spot channels where spot exists - for those times when you maybe have to rasterize something in photoshop.

 

[mschilling]

Actually that is a "trick" I have used in the past. To combine a difficult to print Illustrator file into a photoshop background, you can generate spot color single color pdfs to import into photoshop. There you can define them as spot colors and re-combine into one raster file.

I like what spotlight had to say on raster:

ORIGIN mid 20th cent.: from German Raster, literally ‘screen,’ from Latin rastrum ‘rake,’ from ras- ‘scraped,’ from the verb radere.

 

[claude72]

I have to say that in my 20+ years of doing computer software, I have NEVER heard the term "pixellize", at least in English.

Ok... sorry guys, english is not my native language...

And in french, we make a difference : "rastériser" (which comes from the english verb "rasterise" or "rasterize") is only used for a RIP, outputting 1-bit screened pictures for an imagesetter or a CTP...
... and "pixelliser", litterally meaning "transform in pixels" is used for the transformation of vectors in contone or bitmap pixels by Photoshop.

it is known as rasterization, both in photoshop and a RIP - but its just a name - no issue - we all KNOW what's going on.

On this thread WE all know what's going on, ok, but WE are professionnal designer/printers...
... but in non-professional users minds, the same name for two such different actions is obligatorily a source of confusion...

... and, as many pirated Photoshop used in France are english copies, I understand now why many people in France make also the confusion between "pixellisation" and "rastérisation", opening their PDF in Photoshop and thinking proudly that they have done the same job as the Printer's RIP

I like what spotlight had to say on raster:

ORIGIN mid 20th cent.: from German Raster, literally ‘screen,’

My german dictionnary doesn't know "Raster"...

... but I found "Rastel", meaning "grid"... which is not so different of "screen", as used in printing.

 

[mschilling]

My german dictionnary doesn't know "Raster"...

I was using Spotlight (dictionary) on my Mac.

 

[Lukas Engqvist]

I get sloppy at times with dpi and ppi, wich is basically the same thing. So what you are saying, claude, is in french they use rasterisation to mean converting to dpi, and pixelisation to ppi…Â*wich makes sense.

It's about as sloppy as not remembering that PC doesn't mean microsoft ;P

 

[claude72]

I get sloppy at times with dpi and ppi, wich is basically the same thing.

In France, many people use "dpi" for pictures and printers... professional aware operators make the difference between picture's pixels and printer's dots (ink-jet or laser or imagesetters)...

... but many home-users don't understand this difference, don't understand what are pixels and printer's dots, don't understand what is a résolution... and this confusion gives some funny situations, like for example these people who scann their pictures at their printer's resolution, being sure that a 1440 dpi ink-jet printer needs 1440 dpi contone pictures...

(funny only when you hear the story... but much less funny for the pre-press operator that receives a "ready-to-be-printed" job with 1440 ppi RVB pictures, highly JPEG compressed to put them all on one CD)

To avoid this confusion, when talking on forums and explaining to beginners, I always make the difference and use:
• PPI (pixels per inch) for pictures
• DPI (dots per inch) for printers resolution...


(but i'm not sure of the meaning of "sloppy" ???)

So what you are saying, claude, is in french they use rasterisation to mean converting to dpi, and pixelisation to ppi…�*wich makes sense.

The short answer is "Yes"... but I'm not able to make short answer!!!

The normal french use of the word "rastérisation" is for the conversion in a RIP to a 1-bit picture, made only to be sent to a printer or an imagesetter. So, the rasterisation is always done at a printer resolution, in "DPI".
(although this 1-bit picture is made with pixels... but the resolution of the picture has to match with the resolution of the printer... so both are confused, and "DPI" is used)

And the normal french use of the word "pixellisation" is for the conversion to a picture, made for the general use of a normal picture: send by e-mail, printed with a desktop-printer, imported in a XPress or InDesign layout, imported in a web-site page... etc., etc. So, the unit to be used is "PPI" which is the unit for general purpose picture,...


... but, in fact, in France everybody say "DPI" for both resolutions (printer and picture)...
... and Adobe translates the units in french as "PPP", but "PPP" can mean both:
• "Pixels Par Pouce" = "Pixels Per Inch", which is the unit for pictures
and
• "Points Par Pouce" = "Dots Per Inch", which is the unit for printers,
so the confusion goes on, and many people that began to understand the difference between pixels and dots, "PPI" and "DPI", become confused again by the translation in "PPP"...

That's not an easy job!