I am cropping the original photo to 16:9 which I know how to do it. But I want to have an idea, how it looks like if the 16:9 photo gets a 2nd crop to 2:1?
Is there any way to show a “border” or whatever for 2:1, starting before applying to 16:9?
In other words I want to adjust the 16:9 crop in a way that a 2:1 is ok too. Bottom and top should be cropped the same size for 2:1
There is no need that darktable exports to 2:1. I am using darktable to export to 16:9. Imagemagick is used then to create 2:1
The only way I can see to do this is to flick between the two presets for this. A snapshot might also be another way. I had thought of having two instances of the crop module but this is not an option.
First I have to say, there was a mistarke by me, but i shouldn’t matter. I do a 3:2 export with darktable.
With a little bit feeling you can adjust the crop for 3:2 in a way, that it fits for 16:9, but it is getting harder to have a feeling with 2:1
With a mobile phone I often use OpenCamera, which allows to put a 2:1 frame in the display. This is very helpful because you see how you have to take the picture so a 2:1 cropping contains everything you need. The mobile phone takes the picture in 4:3 (the producers still don’t know that 4:3 is outdated).
Can I get an automatic cropping to 3:2? Since I have the 2:1 frame when taking the shot it will fit for 2:1 and 3:2 is bigger then. In most cases this would do what I need.
I made a big black png with a white 2:1 rectangle and put it in the composite module. Then set blend mode to multiply to get transparency for the white area (it doesn’t seem to support alpha channel yet). You can move, scale and rotate the section with the sliders of the module.
When importing the png to darktable, I would recommend to remove all automatically activated modules to avoid the blueish color shift you can see in my composite module. Also moving composite to the end of the pipeline improves performance and comfort a lot, as every movement will trigger processing from composite on. You can save this as module preset to get quick access to you favorite crops.
What is in my mind, is not possible probably (at the moment).
Let’s say I choose aspect 3:2 and I am cropping, I see the cropped area and the whole area.
Let’s assume the 2nd cropped area is 2:1. During cropping / moving the mouse, I would like to see in another “density”, the 2:1 area.
The problem occurs often, if you want to display the photo with different dispalys in full size. (I hate black borders, especially portrait mode photos on tv). But protrait mode is another topic.
So for TV I need 16:9
for PC it depends, but most times 16:9 or 16:10
For mobile phone, it depends a lot.
At the end, I decided to have 3 formats with different resoultions
3:2 is for paper prints if needed (used for dt output, with maximum resolution)
16:9 for pc monitors in UHD and HD with old phones
2:1 for mobile phones in UHD
I know this means small black borders for the viewer, but otherwise you have to create a lot more variations.
Using the dt output, I create the other variations with imagemagick,
I don’t see a possibility for during cropping but I tried a way less cumbersome method than the composite stuff I showed:
This way, you can see the 2:1 area instantly and automatically after applying a 16:9 crop. I made an svg with 16:9 dimension (1920 x 1080 px) and added black bars at top and bottom (60 px). Loaded this in the watermark module and adjusted opacity to taste. You would need to make multiple svg for different crop combinations.
