Acrobat output preview defaults

[GregB]

This will be easy for most out there, but how can I set the defaults to suit our newspaper specs? I want the simulation profile to stay at isonewspaperv30 and the Total Area Coverage at 240? Where in the preferences do I set these? Looking forward to your help.

 

[Stephen Marsh]

If the PDF has an output intent ICC profile specified, it will override your defaults.

If untagged, then your Acrobat menu/preferences/general/color management/cmyk working space will be used by default for the output preview simulation profile.

The TAC warning should be "sticky" from the last remembered value input into the field.


Regards,

Stephen Marsh

 

[GregB]

It defaults each time to RGB and 280 Coverage

 

[Stephen Marsh]

Using Acrobat Pro 9 on the Mac, the TAC setting is sticky for me, whatever is input into the field remains until changed. The simulation profile defaults to my colour settings CMYK working space - even for an untagged RGB PDF (unless the document has a specified output intent).

Stephen Marsh

 

[ttlcntrlprint]

Acrobat output preview defaults

Hi Stephen, good to see you. I'm keeping this short as I have a baby screaming behind me.
Can you offer your opinion why the RGB values in Acrobat 'output preview' are supplied as percentages. If I decide to save out from InDesign a mixed bag of RGB and CMYK to PDF/X-3 then why does one see strange % numbers instead of 0-255?

Kind regards,
Christian

 

[ttlcntrlprint]

Hi Stephen, apologies for being vague, I now work for a large format printers with a lot of plotters. Moreover, I get supplied CMYK that isn't necessary for my ONYX Production House IMHO. So all sorts of files are coming my way, this does frustratingly include clients saving RGB Pshop, Illu and Indi files as PDF.

This is why I'm concerned why Adobe has no RGB numbers available.

Thanks again,
Christian

 

[Stephen Marsh]

Hi Stephen, good to see you. I'm keeping this short as I have a baby screaming behind me.

Hi Christian, 5 days ago I would have only had a rough idea of what you mean... That all changed 4 days ago, so I now know exactly where you are coming from!

Can you offer your opinion why the RGB values in Acrobat 'output preview' are supplied as percentages. If I decide to save out from InDesign a mixed bag of RGB and CMYK to PDF/X-3 then why does one see strange % numbers instead of 0-255?

The Acrobat programming team would have to reply for a definitive answer. I don't like the % system for 8 bpc RGB either. I would speculate that the display system is independently following the approach used in say Adobe Lightroom...

Ink is easy, 0-100% values. Light expressed in bits per channel values is a little more complex.

The RGB world is not only 8 bpc/256 values. There is also 16 bpc (or in Adobe's case, 15bpc + 1 bit) and then there is also 32 bpc. Although one can display higher BPC values in the info palette in Photoshop - it is much easier for many people to deal with smaller numbers and % readings for higher bits are easier for the masses to work with. Adobe Lightroom further complicates the issue in that the internal working/editing space is linear gamma, while the info readings and histogram are displayed via an sRGB tone response curve - so the % readings for all RGB bit depths are "abstracted" and are not the same as when converted to a final gamma encoded RGB output profile (sRGB, Adobe RGB, ProPhoto RGB etc).

I think that 32 bpc HDR and or video and software such as Adobe After Effects may also work with "normalised" data in the range of 0.0 to 1.0.

Anyway, back to Acrobat (I don't wish to confuse the issue or get sidetracked with Lightroom or other apps).

I see two basic options...do the math each time you need to double check an RGB value (multiply the reported RGB % value by 256, then optionally divide by 100) - or rasterize the entire PDF in Photoshop as RGB or extract the images from the PDF in Photoshop and check their values. This may not be needed all the time, most often one would be concerned with whites - are they really 255rgb/0%? Are blacks really solid 0rgb or 100%? Are neutrals really R=G=B or even values for each of the three channels?


Hope this helps,

Stephen Marsh

 

[Lukas Engqvist]

I would use PDFx4 with output intent a newsprint profile with 240% TAC. Acrobat will view it with the correct profile. It will not automatically set the ink limit but RGB objects will be handled correctly provided you have them tagged correct. If you have any transparency I would strongly advise against PDFx3! Since you going to Newsprint you would probably want transparency blend mode to be CMYK and, you will want colour conversion to be perceptual since you are going to a small profile.

 

[leonardr]

Can you offer your opinion why the RGB values in Acrobat 'output preview' are supplied as percentages.If I decide to save out from InDesign a mixed bag of RGB and CMYK to PDF/X-3 then why does one see strange % numbers instead of 0-255?

All of the different colorspaces(there are 11 of them) in PDF are represented by floating point values in the range of 0-1 - which is (obviously) equivalent to a percentage 0-100. PDF doesn't use the classic 0-255 values for RGB, so there is no reason to display them as such (it would only cause rounding errors and be inaccurate).

If you are using PDF/X-3 (or X-4), then you are also using a CMYK-based OutputIntent - in which case, even though you have RGB values in the document, the final output is in CMYK, so that the percentages displayed in Output Preview are actually in the final CMYK (since its going through the OutputIntent profile as a "simulation").

Hope that explains it!

 

[ttlcntrlprint]

Acrobat output preview defaults

Hi guys, thanks you very much for helping me it's really appreciated.
Big congratulations Stephen.

Thanks again,
Christian

 

[Stephen Marsh]

Hi guys, thanks you very much for helping me it's really appreciated.
Big congratulations Stephen.

Thanks again,
Christian

Thanks Christian, at 9 days we are all trying to establish our new routines!

Leonardr, thanks, I had forgotten that the Acrobat system is in the 0 to 1.00 range, as you say this is easy to convert into a % figure which is what I was remembering from the object inspector of the output preview.

Stephen Marsh