Unfortunately, I don’t, and I’m not sure I’m willing to spend the money to get one just to setup one (old) device.
Whoo, that is a very interesting module, thanks!
For now I use the technique suggested by Aurélien, which is to activate the middle grey border for the image, zoom out, then adjust exposure so that the image looks adjusted to the middle grey border.
OK, I’ll do that then, I was just wondering if darktable was using some kind of database, similar to the lensfun database for automatic lens correction. If that was the case, there could be a better “default” exposure for a given brand/model, but as you mention it might depend a lot on the photograph being taken (subject, lighting conditions).
Pierre, could you please tell more about this? How do you “activate” the “middle grey border”, specifically. I have just started playing with the new (stabile) version and trying to understand it better.
A gray card use is not limited to calibrate a device once.
Even with a new camera, you could use it to set the exposure, but also to correct your white balance in some difficult scenes.
A useful tool to have in your photo bag.
I understand the concept but I have tried this a bit and it doesn’t leave me confident that I am matching that tone at all…I mean perhaps as a rough guide. If I was comparing a monochrome image fine but in color images my brain does not connect the dots as it should I guess…
@Matt_Maguire Is that not the point of adding or subtracting exposure, ie to get part of your image into middle gray tones that you feel should be middle gray or have middle gray properly exposed?? Maybe those aren’t the same things?? Filmic unless you enable the middle gray control as you says uses a value or 18.45 for a central point and then the black and white are reeled in by adding EV to define the dynamic range mapping is that not correct?? Aren’t you defining what it uses or maps to 18.45 by adding or subtracting exposure… I guess you are saying that the middle gray going in to filmic is not changed just the mapping of black and white on either side so it won’t matter for the middle grey area shown in the zone map just how the other zones will shift after filmic black and white ev settings are applied ??
@Pierre its not perfect but you can use the test shots from here to try the various calibration appoaches. They have image pairs of test shots for a few iso with colorcharts. It won’t be as good as if you had a card but it does actually sometimes help with color Olympus E-M5 II Review - Thumbnails
In the dark room (when you edit a picture), there is a light bulb icon at the bottom of the screen:
It’s the “ISO 12646 color assessment mode” that was apparently introduced in darktable 3.0.1. Click on it then zoom out, it should help your eyes to assess the levels of grey in your photo.
Thanks, Pierre.
Judging colors on screen is almost a nightmare for me, especially at night. I can not even see the blue channel of the histogram. That mode is really helpful in this regard.
I have looked through several tutorials on monitor color calibration. One thing is, the calibration is only valid for the ambient light conditions at the time the calibration is done. This implies that colors on the screen are different depending on the light in the room. Not a very comforting thought, but there it is.
Isn’t it more that the colours on the screen appear different depending on the ambient light, because your brain tries to compensate based on ambient conditions?
Very true! Now I process “relatively color-sensitive” images (a totally personal statement, not to be taken seriously!) always under similar lighting conditions. This means never finalizing those images at night.
Slightly off-topic, but is there a way to do this without using the scroll wheel? It doesn’t seem to work for me, which I think is because I have “mouse wheel scrolls module side panel by default” enabled in the settings. But I can’t find a button or setting anywhere to do this without the scroll wheel. I have the same problem in the monochrome module where the scroll wheel is used to change the size of the filter.
That mean I could use the charts pictures to follow this article, but would this work with the filmic model? (i.e. if I use filmic and not base curve to process my pictures)
