Ceci est une ancienne révision du document !
One of our readers, Shane Harvey, asked for more Rawtherapee, so we continue the series beyond the original six parts. So I got asked on Telegram, why should one use Rawtherapee when you can buy something like Luminar4? This got me thinking about my choices. My first and most obvious answer is that Rawtherapee is cross-platform and does not shun LINUX. Secondly, price; Luminar may be *only $89 in your country, but it is $1500 in mine. One of the things that breaks my brain is the way people teach things. A friend has taken up first year accounting at university. The book actually states: ”do not try to understand double-entry bookkeeping, just learn it.”… One of Clark’s laws state: “Any technology, no matter how primitive, is magic to those who don't understand it.” So Luminar may seem magical if you have no idea what is going on in your photographs (…just sayin’).
Un de nos lecteurs, Shane Harvey, a demandé de poursuivre Rawtherapee ; aussi, nous continueons la série au-delà des six premières parties.
Comment on me l'a demandé sur Telegram, pourquoi utiliser Rawtherapee quand vous pouvez acheter quelque chose comme Luminar4 ? Ça m'a amené à réfléchir sur mes choix. Ma premère réponse, et la plus évidente, est que Rawtherapee est cross-plateforme et ne boude pas Linux. En second, le prix : Luminar ne vaut peut-être que 89 $ dans votre pays, mais il vaut 1 500 $ dans le mien.
Une des choses qui me fracassent le crâne, c'est la façon dont les gens apprennent les choses. Un ami s'est inscrit en première année universitaire. Le Livre affirme vraiment : « N'essayez pas de comprendre la comptabilité en partie double, simplement, apprenez-la. » Une des lois de Clarke affirme : « Toute technologie, même la plus primitive, est magique pour ceux qui ne la comprennent pas. » Ainsi, Luminar peut paraître magique si bvous n'avez aucune idée de ce qui se passe sur votre photographies (…juste pour dire).
Let me give you a quick example in the real world. We have all bought crumbed chicken, fish or schnitzel before. The box usually states pan-frying or oven-baking; microwave cooking is not recommended. When you ask yourself why, it is actually obvious, unless you do not know how a microwave works. (Let us assume you did not, for a second… Pan-frying or oven-baking applies heat from the outside. A microwave flips the water molecules inside your food and it cooks/steams from the inside, thus loosening the crumbing so steaming it soggy, as the heat/steam is coming from the inside). Armed with this knowledge, you will not need to be told that the microwave will ruin the crumbed perfection. Let us focus on Rawthereapee and why it is a good choice to invest some of your time into. Now I am not saying Rawtherapee is the be-all and end-all of RAW image processing. All I am saying is that once you understand your tool and when to use it, you will not need to spend money on some tool that you do not know what it is doing in the background.
Rawtherapee 5.8 supports the .cr3 format. Free and out-of-the-box! Here is a quick refresher if you did not know: https://expertphotography.com/cr3-file Rawtherapee not only allows you to undo what you have done, but it keeps a history of what you have done. Unlike other image processing programs, it doesn’t apply “accentuate” or “pop” or “smooth” and you have no idea what just happened. (Back to our microwave example: “hey, why is my crumbing soggy?”). I also have to mention that you can snapshot your work at any point in time and roll back to that snapshot in time, should you need to. For instance, making multiple edits of the same picture, like branching out from a point in time. (Multiple snapshots are allowed).
Rawtherapee allows you to quickly export your photograph to GIMP (if you have it installed) to further edit your pictures. Rawtherapee’s overall design is meant to be simple, and “when you see it” (like the meme), it is actually laid out in the way one works. Not only does one have lens correction, but there is ‘distortion correction’ under the transform tab. This can turn a photograph you may not have considered into a winner. This is really handy for macro photography, where lens kits sometimes cause fisheye. None of your transform tools are hidden from the user, all your sections and sliders are visible down the left. You do not need to turn on a module to see what settings it contains.
Rawtherapee is regularly updated, open source and free. Should you need masking, you can scale to ART. (Which is Rawtherapee with masking, don’t you just love open source?). Let’s get to learning something, shall we? In Rawtherapee 5.8, you will find the section: “Detail” which contains sharpening options. However, there is a section named “RAW”, that will be empty if you loaded up another format picture, like a jpeg. Can you feel a ‘but’ coming on? I can. This section will be populated once you load a RAW image. This is where the ‘but’ comes in, this section also contains ‘capture sharpening’ options, right at the bottom. (You may need to scroll down). It may also not work with certain arb raw formats.
To understand this, you need to be zoomed in 1:1 or larger. Before you start playing with these sliders, I have to point out that this is quite processor intensive. Keep your eye on the ready indicator at the bottom of your screen. The defaults are usually fine, as they cover most scenarios. If you feel you need to adjust – you need to start at the “corner radius boost” slider. Starting at the top – ‘contrast threshold’ may smooth over things that need to have grain. Unlike other controls in Rawtherapee, you will see checkboxes next to the reset arrows of the first two settings. These are the ‘automatic’ settings for those sliders as determined by the built-in algorithm. The reason for this is that it is easy to introduce noise here if the setting is incorrect. That does not mean you cannot use the sliders, just be watchful when you do. The last thing you need is: artefacts when you are trying to sharpen some corners.
TIP: My rule-of-thumb here, is to set my corner radius boost to 0.33. I would say that it is the goldilocks zone for my camera. Find your camera’s goldilocks zone and it will make things a lot easier. A word on iterations. The more iterations, the longer it will take to render the image. You may, or may not, see any benefit here. Truth is that I cannot see the difference between 32 and 64 iterations on any of my images. (This may be due to my advanced age – You kids get off my lawn! - But I encourage you to try it yourself and see). I hope you had fun if you followed along and I hope you learned something. As always, if you have any questions or comments, send them to: misc@fullcirclemagazine.org