Re: [darktable-user] Dark photos when printed
Hi, Niranjan! 1. Without calibrating of your workflow is hard, almost impossible, to help. 2. Calibrating your monitor is a "must do". Some monitors come pretty close to sRGB (at least I don't see HUGE improvement after calibrating them), professional have wider gamut and most laptops are shipped with some sort of display profile of unknown quality (which is lost after OS reinstallation). 3. Printers are even trickier. They are to be calibrated for every paper type you use. My own personal preference - turboprint commercial driver. It comes with good quality profiles (at least I didn't manage to get anything substantially better) but equipment support is limited. 4. Color proofing workflow is something many users forget and I don't remember any darktable specific videos about it. If you don't proof your edits against your printer's profile then you will get gamut mapping of some sorts which translates into problems like uniform dark blobs or lack of details in lights (but darkening is the most common). Timur. On Fri, 2021-03-05 at 21:37 -0800, Niranjan Rao wrote: > Greetings, > > darktable 2.4.1, Ubuntu 20.04 > > > I am just a beginner and first time I tried printing some of photos > I > had. Commercial service from typical drug store on the corner where > you > can upload photos for printing was used. No calibration of my monitor > or > anything except tinkering with few styles until preview and exported > image was acceptable. > > > After printing, photos look little dark - not too dark, but not as > bright as they show up on my monitor. Most of the photos were > captured > on sunny day outside. > > > I am trying to learn why this can be happening. It could be my > laptop > monitor which is showing brighter than it should be or printing > service > could be processing uploaded jpeg image. > > > Any thoughts or hints? Should I be tinkering with any other settings > such as color profiles so that photos don't look dark. > > > Regards, > > > Niranjan > > _ > ___ > darktable user mailing list > to unsubscribe send a mail to > darktable-user+unsubscr...@lists.darktable.org > darktable user mailing list to unsubscribe send a mail to darktable-user+unsubscr...@lists.darktable.org
[darktable-user] Dark photos when printed
Greetings, darktable 2.4.1, Ubuntu 20.04 I am just a beginner and first time I tried printing some of photos I had. Commercial service from typical drug store on the corner where you can upload photos for printing was used. No calibration of my monitor or anything except tinkering with few styles until preview and exported image was acceptable. After printing, photos look little dark - not too dark, but not as bright as they show up on my monitor. Most of the photos were captured on sunny day outside. I am trying to learn why this can be happening. It could be my laptop monitor which is showing brighter than it should be or printing service could be processing uploaded jpeg image. Any thoughts or hints? Should I be tinkering with any other settings such as color profiles so that photos don't look dark. Regards, Niranjan darktable user mailing list to unsubscribe send a mail to darktable-user+unsubscr...@lists.darktable.org
Re: [darktable-user] Can timestamp information in xmp files be altered with external script?
Hi, The timestamps were created precisely to record all darktable's input/output operations. It is therefore normal that the export timestamp is updated with each export. Resetting it to -1 would cause you to irretrievably lose the information. Moreover, as Patrick says in his previous answer, this modification of the xmp file should be saved in the DB, otherwise it will be overwritten during a later export operation. The fact that a checksum calculation is different after an export is quite normal since it reflects the fact that "something happened" to this file. The content of this file is entirely governed by darktable and other photo software. It is therefore unwise to rely on it for other uses. JPV Le 04/03/2021 à 20:29, Patrick Shanahan a écrit : * Bengt [03-04-21 13:02]: The xmp file contains Epoch time information. E. g: darktable:import_timestamp="1614867405" darktable:change_timestamp="-1" darktable:export_timestamp=""1614868405 darktable:print_timestamp="-1" The time information is altered whenever a picture is exported. I. e. not modified, only exported to jpg file for presentation. In case of backing up files into archives, this results in different xml file contents whenever a picture has been exported and in errors when archive versions are compared/checked (md5sum-ing). Questions: 1: Is there any way in darktable to avoid timestamp registration when only exporting or printing? 2: Is it "dangerous" to force export_- and print_timestamps to "-1" by writing an external script that modifies all xml files before archiving (and export/print time information is unimportant for the user)? 3: Any other suggestions? the .xmp is a duplicate of what the library.db contains and, if modified externally (not by dt), affected images need to be re-imported or their xmp files re-read to update library.db. darktable user mailing list to unsubscribe send a mail to darktable-user+unsubscr...@lists.darktable.org
Re: [darktable-user] Can timestamp information in xmp files be altered with external script?
On vendredi 5 mars 2021 10:30:11 CET Jean-Pierre Verrue wrote: > Hi, > > The timestamps were created precisely to record all darktable's input/output > operations. It is therefore normal that the export timestamp is updated > with each export. > > Resetting it to -1 would cause you to irretrievably lose the information. > Moreover, as Patrick says in his previous answer, this modification of the > xmp file should be saved in the DB, otherwise it will be overwritten during > a later export operation. > > The fact that a checksum calculation is different after an export is quite > normal since it reflects the fact that "something happened" to this file. > The content of this file is entirely governed by darktable and other photo > software. It is therefore unwise to rely on it for other uses. Also, if you use a checksum on the whole file for version control, you indicate that you want to see all changes to the file. If you only want to follow part of the information, you'd have to limit your checksum for version control to that part of the info... Remco darktable user mailing list to unsubscribe send a mail to darktable-user+unsubscr...@lists.darktable.org
