Ceci est une ancienne révision du document !
If you have been following our Darktable tutorials, you will know we are working with the latest version, not the version that is bundled in the Ubuntu Software centre. This time, I want you to get a RAW picture. There are a few sites on the internet we can download RAW images from. Please feel free to substitute your own. Sites like: https://www.wesaturate.com/ or https://raw.pixls.us/#repo - be aware that many sites offer RAW downloads but mean raw as in uncooked and jpegs. (The struggle is real…). The reason I want you to use a RAW image is that a lot of the .jpeg or .jpg photos you find have already been manipulated and some tools work on RAW images only.
Si vous suivez régulièrement nos tutoriels sur Darktable, vous savez que nous travaillons sur la dernière version, et non sur la version qui est proposée dans le Centre de logiciels d'Ubuntu.
Cette fois-ci, je veux que vous preniez une image RAW. Il y a quelques sites surInternet où nous pouvons télécharger des images RAW. N'hésitez pas à en prendre une des votres. Des sites comme : https://www.wesaturate.com/ ou https://raw.pixls.us/#repo ; sachez que de nombreux sites proposent des téléchargements de RAW, mais ils confondent raw avec « cru » ou jpeg. (La lutte est réelle…).
La raison pour laquelle je veux que vous utilisiez un image RAW est que beaucoup de photos .jpeg ou .jpg que vous trouverez ont déjà été manipulées et certains outils ne marchent que sur les images RAW.
Disclaimer: In no way am I an expert in photo manipulation, I just know a guy who had a dog that gave me some fleas. I thought I may help you scratch an itch also. (Everything I do can be found here: https://www.darktable.org/usermanual/en/index.html).
Avertissement : Je ne suis nullement un expert en traitement des photos. Je connais simplement un gars qui a un chien qui m'a donné des puces. Je pensais que je pouvais vous aider à vous gratter. (Tout ce que je fais peut être retrouvé ici : https://www.darktable.org/usermanual/en/index.html)
The image we will be working with today, is: https://www.wesaturate.com/photo/cPSYvxuz - please download the RAW image. I created an account for you to use: User: culiz Pass: 123QWE123!! It is a .nef file, but Darktable opens it just fine (and .xmp file).
L'image sur laquelle nous allons travailler aujourd'hui est : https://www.wesaturate.com/photo/cPSYvxuz - Merci de télécharger l'image RAW.
J'ai créé un compte que vous pouvez utiliser : Utilisateur : culiz Mot de passe : 123QWE123!!
C'est un fichier .nef, mais Darktable l'ouvre sans problème (ainsi que le fichier .xmp).
We are continuing from last issue. If you still have the edited image, please open it now. We have our image, more-or-less where we want it mood-wise, but it is drab. Let’s start with the green trees. Open the “color picker” in the left pane. Zoom into the area with the trees. Click in the eye dropper icon in the “color picker”, and make sure “area” is selected. Select an area and work diagonally left-to-right or right-to-left and sample 4 areas. Remember to click on the word “add” to save your sample each time. Leave the first column as “mean”, and change the second one from “RGB” to “Lab”. Mentally note the ratio of your samples. Open the white balance module on the right. We will adjust it so that the ratio is about half, or 2:1. Since we are working with green, and it is a very grey picture, try to keep green around 1.0.
Nous prenons la suite du numéro précédent. Si vous avez encore l'image modifiée, ouvrez-la maintenant, s'il vous plait. Nous avons notre image, plus ou moins dans l'ambiance que nous voulons, mais elle est terne. Commençons avec les arbres verts.
First I want you to move the temperature slider, but keep an eye on the red slider. See how one slider affects another? If you are working at night, remember to turn off night light or redshift. You can move the sliders, which can be tricky. You can also hold your mouse over the color you want and roll the mouse wheel for a fine grained approach. It does not have to be perfect. More-or-less is good. Keep an eye on your histogram. You do not want it cropping.
On a quick side note, go to the “color group”. Open the channel mixer. Here is another “Time travel” feature we still have to look at. Hue, saturation and lightness will let us change the time of day. Not as big a gap as our previous tutorial, but file that in your todo-file. I will give you an example here: This is NOT what we want to do here though, just an interesting factoid. Adjusting the “L” color space, just one click of the mouse may turn your image black. Think of it as word-wrap in a text program. (Pay attention to your histogram as you move your sliders). It will wrap around as you move from one to zero or zero to one. We want to separate the colors to heighten the contrast, without making it look like it is fake. Remember this will bleed into anything white, so be careful!
Back to our current edit. Open the local contrast module. Take a snapshot before you begin. Because of the lighting situation, we made our picture more uniform. We ended up with a bit of a white-wash. Time to fix that. In my case I bring the detail up to about 150%, the highlights down to about 50% and the shadows to about 150%. Again, you make yours as you see fit. Because you took a snapshot, you can now drag your slider to see the difference (bottom left). I have to make it clear that there are many ways to skin a cat in Darktable. This is not the only way to do what we are doing, but it is one way. This leaves us with the sky not quite blue and neither the river. Also we need the clouds to ‘pop’, but not as garish as the picture was on the website. To make the clouds more ‘tangible’, let us use a low pass filter.
Open your low pass filter, and change the “blend mode” to “drawn mask”. This should be familiar if you have been following along. This time, place your line roughly on the top edge of the two trees on the right. Pay attention to the fill side. Everything above this line will now be edited. You can turn off “saturation” to get rid of any color that may confuse the issue. I took my ‘radius’ up to 15 (mine was 10). Change your blend mode to “softlight” to apply the changes. I urge you to use “hardlight” as well to see the difference. I brought my opacity down to 75-85% . Collapse the low pass and create a copied instance, this time changing the opacity to between 50-60%. We want classy clouds, not just lumps in the sky. You can even do it a third time, just remember that the treetops are also in this ‘band’. Keep an eye on that histogram, keeping it in the centre, as we are feathering the edges.
Now let us get a high-pass filter going, where we boost the sharpness and contrast to 100% and apply it uniformly. Let us go to the “contrast, brightness, saturation” module and I changed mine slightly to 0.06 contrast, -0.06 brightness and 0.25 saturation. This gives the ‘cold’ picture a more ‘warm’ feel. Now for the water. Go to the “color correction” module and create two drawn masks facing each other as before. Grab the centre point and drag it into the blue. (or turquoise, whatever floats your boat). See image bottom right. Please let me reiterate, this is not the “correct” way to do this, but it teaches you the tools and methods used in post-processing.
Now the sky. This will be your homework with what you have learned so far in this series. Nowhere is anything set in stone, feel free to experiment! Here is an edit vs. original: