Que fait le bruit sur Darktable et mon Z5-II

Le module Réduction du bruit (profil)enlève tout les détails à mes photos ! Il n’existe pas encore de profiles de bruit pour le Nikon Z5-II. Pizzacutter-at-tty3 a soumis un profile à la communauté Darktable que je m’empresse de télécharger.

Il faut modifier le fichier noiseprofiles.json dans le dossier de configuration de Darktable après une sauvegarde du fichier original :

sudo cp /usr/share/darktable/noiseprofiles.json /usr/share/darktable/noiseprofiles.json.bak
sudo gnome-text-editor /usr/share/darktable/noiseprofiles.json

Utilisez l’éditeur de votre distribution ( ici c’est pour Gnome-Shell ) et copiez dans le fichier ouvert ce qui se trouve ci-dessous, y compris la dernière virgule. Je l’ai collé dans la section "maker": "Nikon" après { ... "model": "Z 5" ... },

{
"comment": "z5_2 contributed by xpizza",
"model": "Z5_2",
"profiles": [
{"name": "Z5_2 iso 50", "iso": 50, "a": [1.05543412294938e-06, 5.15789743107638e-07, 1.23433773531925e-06], "b": [1.64431938834834e-09, 9.70987383776412e-10, 1.65759604952011e-09]},
{"name": "Z5_2 iso 64", "iso": 64, "a": [1.05595178373914e-06, 5.20442103949492e-07, 1.24349584266733e-06], "b": [1.5871885381903e-09, 1.01193267964317e-09, 1.61500678780683e-09]},
{"name": "Z5_2 iso 80", "iso": 80, "a": [1.05937788045217e-06, 5.23570899138627e-07, 1.2523361191475e-06], "b": [1.43411537329079e-09, 8.51073752175325e-10, 1.46862871962695e-09]},
{"name": "Z5_2 iso 100", "iso": 100, "a": [1.06277226176673e-06, 5.30182698272982e-07, 1.26133964694909e-06], "b": [1.34965043519592e-09, 8.06416522249818e-10, 1.4027610848054e-09]},
{"name": "Z5_2 iso 125", "iso": 125, "a": [1.32377467511645e-06, 6.52867328848006e-07, 1.55796201091689e-06], "b": [1.66318866303404e-09, 9.38555108577591e-10, 1.64839796595601e-09]},
{"name": "Z5_2 iso 160", "iso": 160, "a": [1.64843289981963e-06, 8.12707536211625e-07, 1.93368933851475e-06], "b": [2.09918362094711e-09, 1.27356380806919e-09, 2.17253408361264e-09]},
{"name": "Z5_2 iso 200", "iso": 200, "a": [2.05749153162138e-06, 1.00574496538121e-06, 2.40227236024934e-06], "b": [2.69547430484791e-09, 1.66157658956898e-09, 2.77474478835565e-09]},
{"name": "Z5_2 iso 250", "iso": 250, "a": [2.60774814939197e-06, 1.26163573538427e-06, 3.01061587563385e-06], "b": [3.45747266533049e-09, 2.09797293773897e-09, 3.44407437449496e-09]},
{"name": "Z5_2 iso 320", "iso": 320, "a": [3.30943232795203e-06, 1.58294533117364e-06, 3.77832578666969e-06], "b": [4.45770058261575e-09, 2.69995145710858e-09, 4.56596513152934e-09]},
{"name": "Z5_2 iso 400", "iso": 400, "a": [4.92852305309996e-06, 2.26063196386596e-06, 5.3300987164165e-06], "b": [7.58860236506574e-09, 4.66823524922377e-09, 7.7786897369421e-09]},
{"name": "Z5_2 iso 500", "iso": 500, "a": [6.18831619192405e-06, 2.83692122568372e-06, 6.71007114182838e-06], "b": [1.00742972845158e-08, 6.22248730983142e-09, 1.00979543375008e-08]},
{"name": "Z5_2 iso 640", "iso": 640, "a": [7.90158751978637e-06, 3.59068757214521e-06, 8.49078790658999e-06], "b": [1.31629221700223e-08, 8.2060220459364e-09, 1.32114083793853e-08]},
{"name": "Z5_2 iso 800", "iso": 800, "a": [9.93967444041079e-06, 4.5855879351119e-06, 1.08819125693217e-05], "b": [8.38988649816833e-09, 5.06034678088026e-09, 8.63355764909371e-09]},
{"name": "Z5_2 iso 1000", "iso": 1000, "a": [1.25484186599743e-05, 5.79439665566944e-06, 1.36082302280001e-05], "b": [1.07868769851521e-08, 6.48520107258128e-09, 1.09250707752261e-08]},
{"name": "Z5_2 iso 1250", "iso": 1250, "a": [1.58489030573477e-05, 7.28134954945624e-06, 1.71856080225112e-05], "b": [1.35391698939416e-08, 8.30389704719179e-09, 1.37003230992939e-08]},
{"name": "Z5_2 iso 1600", "iso": 1600, "a": [2.01623039241968e-05, 9.23205963306314e-06, 2.17598211710671e-05], "b": [1.70591789410487e-08, 1.05446295702777e-08, 1.73215403719619e-08]},
{"name": "Z5_2 iso 2000", "iso": 2000, "a": [2.52987926222679e-05, 1.15958798420035e-05, 2.73750679994442e-05], "b": [2.16961036640997e-08, 1.35752473697326e-08, 2.17074171368614e-08]},
{"name": "Z5_2 iso 2500", "iso": 2500, "a": [3.20210906763637e-05, 1.46076159729743e-05, 3.45589046410053e-05], "b": [2.75269015644037e-08, 1.72850892529245e-08, 2.75741561939041e-08]},
{"name": "Z5_2 iso 3200", "iso": 3200, "a": [4.0738128550906e-05, 1.86681750235774e-05, 4.37181312485899e-05], "b": [3.48584476814219e-08, 2.19461711316858e-08, 3.46886440783775e-08]},
{"name": "Z5_2 iso 4000", "iso": 4000, "a": [5.119715740388e-05, 2.32399436881746e-05, 5.48657434950801e-05], "b": [4.40273899217837e-08, 2.79225437020015e-08, 4.38681370485139e-08]},
{"name": "Z5_2 iso 5000", "iso": 5000, "a": [6.49681735614401e-05, 2.95669655829053e-05, 6.96121004583471e-05], "b": [5.6159537185062e-08, 3.57611487658595e-08, 5.54930549602839e-08]},
{"name": "Z5_2 iso 6400", "iso": 6400, "a": [8.2187296581693e-05, 3.73208928428998e-05, 8.78046676222333e-05], "b": [7.1895596002973e-08, 4.62091342133481e-08, 7.00110352028156e-08]},
{"name": "Z5_2 iso 8000", "iso": 8000, "a": [0.000103898997557921, 4.72386938417261e-05, 0.000110752624925533], "b": [9.19758395425261e-08, 5.90325173109753e-08, 8.92921487337755e-08]},
{"name": "Z5_2 iso 10000", "iso": 10000, "a": [0.000131166997843419, 5.99015964887616e-05, 0.000140431859543502], "b": [1.17962600932813e-07, 7.6051097325253e-08, 1.12936976444849e-07]},
{"name": "Z5_2 iso 12800", "iso": 12800, "a": [0.00016624832538009, 7.54075471613274e-05, 0.000176598374894905], "b": [1.52332459433249e-07, 9.92546637391457e-08, 1.45964115062885e-07]},
{"name": "Z5_2 iso 16000", "iso": 16000, "a": [0.000208076436765859, 9.47423698536289e-05, 0.000220403733330026], "b": [1.65243705712683e-07, 1.06782437157547e-07, 1.58827711738474e-07]},
{"name": "Z5_2 iso 20000", "iso": 20000, "a": [0.000262728088908774, 0.00012028414202361, 0.000277574312633099], "b": [2.23289314074965e-07, 1.47852243921636e-07, 2.1185896745665e-07]},
{"name": "Z5_2 iso 25600", "iso": 25600, "a": [0.000333248551856214, 0.000152279937983695, 0.000349391268109368], "b": [2.86469161627632e-07, 1.98613455235335e-07, 2.73458168015173e-07]},
{"name": "Z5_2 iso 32000", "iso": 32000, "a": [0.000424451585546736, 0.000194852544695005, 0.000444424857957489], "b": [3.59224286721581e-07, 2.66958763850263e-07, 3.4254731642973e-07]},
{"name": "Z5_2 iso 40000", "iso": 40000, "a": [0.000537656885313226, 0.000248511607596712, 0.000558525993857847], "b": [4.52131971977505e-07, 3.62190529575498e-07, 4.32088233821512e-07]},
{"name": "Z5_2 iso 51200", "iso": 51200, "a": [0.00068473419064882, 0.00031786349422516, 0.000713834675347537], "b": [5.3942088498286e-07, 4.80898689856563e-07, 5.33107993104435e-07]},
{"name": "Z5_2 iso 64000", "iso": 64000, "a": [0.000866936200685197, 0.000409411967879526, 0.000897544816960594], "b": [5.93282425763206e-07, 6.25005142659445e-07, 6.33065956175001e-07]},
{"name": "Z5_2 iso 80000", "iso": 80000, "a": [0.00109755550513683, 0.000525214023808076, 0.00113030780288005], "b": [6.30845128987969e-07, 8.0059405114121e-07, 7.41488611603759e-07]},
{"name": "Z5_2 iso 102400", "iso": 102400, "a": [0.0013789549388839, 0.000676167405376593, 0.00141161310046727], "b": [5.68139869580706e-07, 1.01119598307468e-06, 8.34642057723366e-07]},
{"name": "Z5_2 iso 128000", "iso": 128000, "a": [0.00171652651064211, 0.00086663601168899, 0.00174875888188242], "b": [3.11402149492328e-07, 1.25513428912799e-06, 8.32997467204537e-07]},
{"name": "Z5_2 iso 204800", "iso": 204800, "a": [0.00269534408990771, 0.00142666533116332, 0.00270897753165689], "b": [-7.91570408628615e-07, 1.93854889524339e-06, 8.03721914238101e-07]}
]
},

En supprimant les développements des photos déjà trop débruitées, Darktable relance la Réduction du bruit (profil)avec le bon profile.