RE: [darktable-user] how to correct lens distortion when no camera / lens defined
Hi Pascal and Remco, Thank you for advising. I tried Pascal's advice, but it's not helping for existing pincushion distortion. I found though that GIMP seems to do what I need, after looking to a video. I don't think there is a lot of demand for such a feature within darktable, so I'll go to GIMP for this occasional issue. Thanks, Marc. -Oorspronkelijk bericht- Van: Pascal Obry Verzonden: zaterdag 1 oktober 2022 11:50 Aan: marc.ca...@gmail.com; darktable-user@lists.darktable.org Onderwerp: Re: [darktable-user] how to correct lens distortion when no camera / lens defined Hi Marc, > Is there a way to correct lens distortion when no camera or lens is > defined in the EXIF of the TIFF file? Yes, the lens correction module has a generic model where you can apply some distortion controlled manually. > btw I enjoy using dt since 2 years (switched from LR), especially this > latest 4.0.1 is running fast on my laptop (thanks to the opencl > performance tuning parameters/enhancements) That's nice to hear! Thanks, -- Pascal Obry / Magny Les Hameaux (78) The best way to travel is by means of imagination http://www.obry.net gpg --keyserver keys.gnupg.net --recv-key F949BD3B darktable user mailing list to unsubscribe send a mail to darktable-user+unsubscr...@lists.darktable.org
Re: [darktable-user] xmp metadata and language
That's very interesting, and it makes sense. Thanks Volker Am 30.09.22 um 21:37 schrieb Top Rock Photography: Not entirely certain of this, but here is my understanding of the language tag and the title/description (etc.) fields. There can be several title/description fields; one for each language. A language field set as “default” means, “Use this title/description when no language is given by the viewer, or if the viewer's preferred language is not present.” Any field with a specified language means, “use this title/description if the viewer's preferred language matches this one.” E.g., if I have English (non-specific) language title listed as, “Bread & Wine Festival”, French language title as, « La fête du pain et du vin », and default language title as, “Trinidad September Celebration”, then anyone with their language set to anything but French or English will see, “Trinidad September Celebration,” while someone with their language set to English or French will see the appropriate title, (and the French will see the accent in « fête »). This will mean that, if I only had one language title set up, default, with, « La fête du pain et du vin », and the circumflex shows up as tofu, changing my language to French is not necessarily going to make the ‘ê’ suddenly show up. Why Gimp is showing an empty string is that you had a default language title, in Arcen, then /added/ a second language title in Arcen-Schlossgärten to the file, without adding the new title. So when your viewer language is set to, “Arcen. Schlossgärten,” Gimp correctly shows you the appropriate title field, which is empty, instead of the “default/Arcen” title field, in Arcen-Schlossgärten language. So one wants to change the metadata encoding of the XMP metadata to UTF-8 so that one gets the accents instead of tofu, (which, I understand, is possible for XMP data but not for IPTC data), but also add a title in Arcen-Schlossgärten, (or change the default language from “default:Arcen”, to “default:Arcen-Schlossgärten”). IIRC,the default encoding for XMP data is, indeed, UTF-8, which is more than adequate for most non-CJK languages —which need UTF-16-cs, I understand,— and that the default —and only— encoding for IPTC is Latin-1. I may be wrong on this. The long and short is that some accented characters may not show up in IPTC title fields, and adding a title language in metadata will only show up if the new title is also added along with the language. Please, others correct what I may have incorrect here. Sincerely, Karim Hosein Top Rock Photography 754.999.1652 On Thu, 29 Sept 2022 at 13:14, Volker Lenhardt mailto:volker.lenha...@uni-due.de>> wrote: But I'm sorry, but to include iptc tags doesn't seem to have any effect on the xmp tags. I do get xmp.dc.title and xmp.dc.description, but gimp shows an empty string whenever there is a special character within. I'm not sure if it is a gimp problem, but I cannot find the trick to tell it to use utf-8 with metadata. I hope that dt exports them as utf-8. 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
Re: [darktable-user] how to correct lens distortion when no camera / lens defined
Hi Marc, > Is there a way to correct lens distortion when no camera or lens is > defined in the EXIF of the TIFF file? Yes, the lens correction module has a generic model where you can apply some distortion controlled manually. > btw I enjoy using dt since 2 years (switched from LR), especially > this latest 4.0.1 is running fast on my laptop (thanks to the > opencl performance tuning parameters/enhancements) That's nice to hear! Thanks, -- Pascal Obry / Magny Les Hameaux (78) The best way to travel is by means of imagination http://www.obry.net gpg --keyserver keys.gnupg.net --recv-key F949BD3B darktable user mailing list to unsubscribe send a mail to darktable-user+unsubscr...@lists.darktable.org
Re: [darktable-user] how to correct lens distortion when no camera / lens defined
On samedi 1 octobre 2022 11:28:23 CEST marc.ca...@gmail.com wrote: > Hello fellow dt users, > > Is there a way to correct lens distortion when no camera or lens is defined > in the EXIF of the TIFF file? > > I am experimenting with a few old camera's (60's and 70's ) and have the b/w > film developed and scanned by a lab. One of my pictures is showing cushion > distortion but I can't use the 'lens correction' module and try to enhance > the picture. The lens correction module doesn't allow me to change settings > because the lens is undefined (in the lensfun database). Should I use > another module ? Or, since it's about a TIFF file, perhaps another open > source program can deal with this ? > > I am using dt 4.0.1 on Windows 10. I think Hugin can create lens distortion models, and use them (and those models can be used in lensfun, so you could add the lenses to your private lensfun database, and/or upload them). Do keep in mind that your images must contain straight lines for this to work. See e.g. https://hugin.sourceforge.io/tutorials/calibration/en.shtml Remco darktable user mailing list to unsubscribe send a mail to darktable-user+unsubscr...@lists.darktable.org
[darktable-user] how to correct lens distortion when no camera / lens defined
Hello fellow dt users, Is there a way to correct lens distortion when no camera or lens is defined in the EXIF of the TIFF file? I am experimenting with a few old camera's (60's and 70's ) and have the b/w film developed and scanned by a lab. One of my pictures is showing cushion distortion but I can't use the 'lens correction' module and try to enhance the picture. The lens correction module doesn't allow me to change settings because the lens is undefined (in the lensfun database). Should I use another module ? Or, since it's about a TIFF file, perhaps another open source program can deal with this ? I am using dt 4.0.1 on Windows 10. Thank you in advance, Marc. PS btw I enjoy using dt since 2 years (switched from LR), especially this latest 4.0.1 is running fast on my laptop (thanks to the opencl performance tuning parameters/enhancements) darktable user mailing list to unsubscribe send a mail to darktable-user+unsubscr...@lists.darktable.org
