On Wed, Aug 7, 2019, at 00:49, Remco Viëtor wrote:
> Still, if there would be a possibility to tell dt which lenses you actually
> possess, it might be possible to get the XMP field filled out automatically,
> which would be useful, especially in relation with lensfun/lens correction.
Well, for what it's worth, attached are crudely abstracted versions of the Lua
scriptst I'm currently using for managing old manual lenses on my Olympus
cameras. I use the copyright fields in-camera to assign a short lens ID string
(and theoretically also an aperture value, but in reality I rarely take the
trouble to set this; it defaults to maximum). When a "dumb" lens is used, the
field in my camera RAW files contains "None", so on import I check for this and
flag the image with the "red" color code for utility purposes, and then search
a list of my lenses for a matching ID to map to a lens name.
On export, images with the "red" flag have the contents of that field filled
with the lens name by exiftool, for posterity. It's an ugly, dirty, clumsy
hack, but it works pretty well for me, and could probably be adapted to use
with other cameras and workflows. Oh, it also adds a lightable module for
manually filling in this information, since I often forget to actually change
the settings in-camera and need to fix it later... that might be the most
generally useful part. :)
Anyway, if anybody wants to create something more user-friendly based on this,
it can be considered public domain for that purpose. Short of that, it should
be considered pseudo-code... please don't attempt to use it if you aren't
already comfortable with Lua scripting.
--
jys
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local dt = require "darktable"
local my_lenses = require "_mystuff/myLenses"
dt.register_event("post-import-image",
function (event, image)
if image.exif_lens == "None" then -- Apply a red label to any import missing lens info
image.red = true
if not (image.creator == "") then -- Check for anything matching a lens ID in this field
local found_lens = Nil
for i, lens_record in ipairs(my_lenses) do
if lens_record["id"] == image.creator then
found_lens = lens_record
end
end
if found_lens then
image.exif_lens = found_lens.name
image.exif_focal_length = found_lens.fl
if image.rights == "" then -- Did I also manually set an f-number in camera?
image.exif_aperture = found_lens.fnum -- If not, just use the f_num value from the lens db
else
image.exif_aperture = image.rights
end
end
end
end
image.creator = "" -- Clear these fields now that we're done abusing them
image.rights = ""
end
)
dt.register_event("intermediate-export-image",
function (event, image, filename, format, storage)
if format.mime == "image/jpeg" then
local lens_exif = ""
if image.red == true then
lens_exif = "'-LensModel=" .. image.exif_lens .. "' '-FocalLength=" .. image.exif_focal_length .. "' '-FNumber=" .. image.exif_aperture .. "' '-MaxApertureValue=" .. image.exif_aperture .. "' '-LensInfo=" .. image.exif_focal_length .. " " .. image.exif_focal_length .. " " .. image.exif_aperture .. " " .. image.exif_aperture .. "' "
end
os.execute("exiftool -overwrite_original -v -m " .. lens_exif .. filename )
end
end
)
local dt = require "darktable"
local lens_db = { -- Create a table of records for each lens
{id = Nil, name = "None", fl = "", fnum = ""},
{id = "1", name = "koifisheye 7.5mm f/3.5", fl = "7.5", fnum = "3.5"},
{id = "2", name = "blechinon super ultragon 50mm f/1.4", fl = "50", fnum = "1.4"},
{id = "3", name = "fubagon 25mm f/1.9", fl = "25", fnum = "1.9"},
}
local lens_list = {} -- Make a pretty list of names for combobox
for i, lens_record in ipairs(lens_db) do
lens_list[i] = lens_record["name"]
end
local fl_entry = dt.new_widget("entry"){
placeholder = "0",
editable = true,
tooltip = "Lens focal length"
}
local fnum_entry = dt.new_widget("entry"){
placeholder = "0",
editable = true,
tooltip = "Lens f/number"
}
local name_combobox = dt.new_widget("combobox"){
changed_callback = function (self)
local lens_record = lens_db[self.selected]
if lens_record then
fl_entry.text = lens_record["fl"]
fnum_entry.text = lens_record["fnum"]
end
end,
editable = true,
table.unpack(lens_list)
}
local apply_button = dt.new_widget("button"){
label = " apply ",
clicked_callback = function (_)
local counter = 0
for i, image in ipairs(dt.gui.action_images) do
image.exif_lens = name_combobox.value
image.exif_focal_length = fl_entry.text
image.exif_aperture = fnum_entry.text
counter = i -- Just take the last index
end
dt.print("lens data applied to "..counter.." images")
end
}
dt.register_lib(
"myLenses", -- Module name
"myLenses", -- name
true, -- expandable
false, -- resetable
{[dt.gui.views.lighttable] = {"DT_UI_CONTAINER_PANEL_RIGHT_CENTER", 1}},
dt.new_widget("box"){
orientation = "vertical",
name_combobox,
dt.new_widget("box"){
orientation = "horizontal",
apply_button, fl_entry, fnum_entry,
},
},
nil,-- view_enter
nil -- view_leave
)
return lens_db -- Export lens data to other scripts that require this one
