How to create camera noise profiles for darktable


(Chris E) #41

It certainly seems to give a better range of brightness than your previous method though (albeit a bit of a jump between the overexposed area and the lightest part of your printed gradient - not sure if there’s any way to improve this, apart from possibly defocussing a bit more?).

It still seems a rather involved process, though, compared to the alternative (shooting a point light source against a wall in a dark room). I think both times I submitted noise profiles it took less than 20 minutes from turning my camera on to submitting the results for inclusion. Does this new method give noticeably better results than that?


(Andreas Schneider) #42

The interesting part is normally in the gray area. If it goes from black to white you see the noise in the gradient. Here we just create a huge gradient so the zone for detecting the noise is a nice large area. However the printed gradient could be better but I think my laser printer doesn’t do the best job here.

I will create a new profile for my camera today. I just did a quick run through yesterday.


(Chris E) #43

It appears to produce a good gradient for those that are willing to take the effort. Personally I’m lazy and having to go out and buy equipment would probably be more than enough to put me off bothering - I only submitted profiles myself because it was so easy! And of course not everyone has a printer (if you can believe it). If you want to encourage more people to submit noise profiles, I think you should describe the simpler alternative alongside the printed gradient method so people can choose which one to use.

It’s also worth noting in your tutorial that if your camera is supported by gphoto2 the noise profiling script will even take all the photos for you (at the various ISOs), meaning the only real effort required is to set up your camera pointing to an appropriate target, plug it into your computer and run the script.


(Andreas Schneider) #44

It should be easy to get a working profile with this approach. The issue with the original method, light somewhere and defocusing is that it did not reliably produce a working result always. With this approach the grey zone for the noise is huge. You should always get a working profile out of this.

I think most people know someone with a printer or have one at work. It shouldn’t be hard to print out a gradient on normal paper.


#45

Hi, i have a software problem. At the time, i realized the noise profile for the Canon 5Dc with some success (it’s in the Darktable database) but now with the new Darktable version, it doesn’t work at all… I want to do the Phaseone P65+ noise profile, i have the errror “can’t find the darktable-cli”. I followed the instructions above, it’s a fresh compilation but the compiled noise tools is in another folder. I need help!


(Mica) #46

Add darktable-cli to your path.