reading of cmyk-files

This forum is closed to new entries. Please use the Picture Window Support forum instead.

Moderators: ksinkel, jsachs

Locked
Winfried
Posts: 239
Joined: June 18th, 2010, 4:27 pm
What is the make/model of your primary camera?: Pentax K1

reading of cmyk-files

Post by Winfried »

I just tried to open a cmyk-file.
The following messages showed up:
Error-message
Error-message
PWP-Error.jpg (16.54 KiB) Viewed 9294 times
But the modul "Ltclr15u.dll" from the support page does not work.
Winfried
-----
migrated to Windows 10 in Nov. 2019
PWP Pro 64
CUDA not available
ksinkel
Posts: 594
Joined: April 2nd, 2009, 11:58 am
Contact:

Re: reading of cmyk-files

Post by ksinkel »

The Ltclr15u.dll download on our web site is intended to support PWP 5 and is a 32 bit dll.

Currently for PWP 6 (and PWP 7) only the 32 bit versions support reading cmyk files and require no additional downloads. So the simplest immediate solution is to download PWP/32 and read the files that way. (Both PWP 32 and 64 versions can be installed at the same time.)

Kiril
Kiril Sinkel
Digital Light & Color
jsachs
Posts: 4203
Joined: January 22nd, 2009, 11:03 pm

Re: reading of cmyk-files

Post by jsachs »

I haven't tried it but there is an online conversion service:

http://www.cmykconverter.com/
Jonathan Sachs
Digital Light & Color
alain
Posts: 95
Joined: September 27th, 2010, 7:18 am
What is the make/model of your primary camera?: A850

Re: reading of cmyk-files

Post by alain »

ksinkel wrote:The Ltclr15u.dll download on our web site is intended to support PWP 5 and is a 32 bit dll.

Currently for PWP 6 (and PWP 7) only the 32 bit versions support reading cmyk files and require no additional downloads. So the simplest immediate solution is to download PWP/32 and read the files that way. (Both PWP 32 and 64 versions can be installed at the same time.)

Kiril
Thanks

Nice to know. Can it convert to cmyk too (with an icc profile)?
Sometimes a cmyk file is asked by some printers.
ksinkel
Posts: 594
Joined: April 2nd, 2009, 11:58 am
Contact:

Re: reading of cmyk-files

Post by ksinkel »

No. PWP does not support conversion to cmyk.

Kiril
Kiril Sinkel
Digital Light & Color
Dieter Mayr
Posts: 453
Joined: April 24th, 2009, 11:47 am
What is the make/model of your primary camera?: Nikon D700
Location: Salzburg / Austria

Re: reading of cmyk-files

Post by Dieter Mayr »

alain wrote:Nice to know. Can it convert to cmyk too (with an icc profile)?
Sometimes a cmyk file is asked by some printers.
Alain, some additional thoughts about converting to CMYK:
I had a discussion about this with the owner of the printshop where I let print my calendars.
The conversion to CMYK is not a simlpe task that should be done by the photographer.
There are a lot of parameters that infuence the conversion as the exact print process or the paper quality.
Cyan, Magenta and Yellow printed together give theoretically black, but not in the real world, so additional blacK is introduced in the process. But the way black is composed by the 4 colors may vary depending on the process and paper.
So one process may need 100% C, 100% M, 100% Y and 100% K, or a other process may need 0% CMY and 100% K.
To decide this needs expierience and knowledge of the process.
So, as he said, printers that require CMYK files from their customers are either lazy or want to burden all the responsibility for a good result to the customer.
So to say "YOU have made the CMYK file, you are responsible for the result, not our problem.
A good printer should always make the CMYK separation to his or her specific needs.

Excuse please for the longer excurs, but i hope it's interesting to some that did not know the insights.
Dieter Mayr
ksinkel
Posts: 594
Joined: April 2nd, 2009, 11:58 am
Contact:

Re: reading of cmyk-files

Post by ksinkel »

I think Dieter has made an important point. The canonical image is the rgb image which one produces using appropriate editing tools to adjust all the image parameters to achieve the intent of the artist. Manipulation beyond that point is simply technical and relates to translating that image in a way that can best be reproduced by a given process. There is nothing special about cmyk -- it is simply a common printing technology. As we know, many photo quality printers use CcMmYKk instead. But our editing programs do not produce CcMmYKk files. That conversions is done by the printer driver which uses strategies that are specific to the ink set and needs of that particular printer model. The details of how the conversion is done is fundamentally part of the design of the print process and thus properly the task of the driver and not the editing program. The same reasoning applies to printing via a service -- it is really the service's responsibility to make a conversion that matches the characteristics of their process.

Kiril
Kiril Sinkel
Digital Light & Color
alain
Posts: 95
Joined: September 27th, 2010, 7:18 am
What is the make/model of your primary camera?: A850

Re: reading of cmyk-files

Post by alain »

Dieter Mayr wrote:
alain wrote:Nice to know. Can it convert to cmyk too (with an icc profile)?
Sometimes a cmyk file is asked by some printers.
Alain, some additional thoughts about converting to CMYK:
I had a discussion about this with the owner of the printshop where I let print my calendars.
The conversion to CMYK is not a simlpe task that should be done by the photographer.
There are a lot of parameters that infuence the conversion as the exact print process or the paper quality.
Cyan, Magenta and Yellow printed together give theoretically black, but not in the real world, so additional blacK is introduced in the process. But the way black is composed by the 4 colors may vary depending on the process and paper.
So one process may need 100% C, 100% M, 100% Y and 100% K, or a other process may need 0% CMY and 100% K.
To decide this needs expierience and knowledge of the process.
So, as he said, printers that require CMYK files from their customers are either lazy or want to burden all the responsibility for a good result to the customer.
So to say "YOU have made the CMYK file, you are responsible for the result, not our problem.
A good printer should always make the CMYK separation to his or her specific needs.

Excuse please for the longer excurs, but i hope it's interesting to some that did not know the insights.
Thanks Dieter

A very useful contribution.

Maybe another question : Is it possible to softproof a CMYK device with pwp. There are icc profiles available and so the RGB can already "prepared" for the cmyk gamut.
Dieter Mayr
Posts: 453
Joined: April 24th, 2009, 11:47 am
What is the make/model of your primary camera?: Nikon D700
Location: Salzburg / Austria

Re: reading of cmyk-files

Post by Dieter Mayr »

alain wrote:Maybe another question : Is it possible to softproof a CMYK device with pwp. There are icc profiles available and so the RGB can already "prepared" for the cmyk gamut.
It is possible to choose a CMYK profile as a proof profile and make a softproof, but I can't say how accurate this is.
Dieter Mayr
Locked