When you take an image with your camera, the auto-metering will normally try to set the exposure so that the average brightness of the image is around middle grey. However, if the scene is dominated by dark tones, this can cause the exposure to set brigher, and cause highlights to be clipped. So, you need to dial in some negative exposure compensation to protect those highlights. Alternatively, a scene dominated by bright tones will cause the exposure to be reduced, and in order to avoid noise in the shadows, you want to increase the exposure compensation to boost the shadows while making sure you don't clip the highlights.
The "compensate camera exposure" setting is designed to undo these compensation adjustments that were made in order to place the scene within the optimum dynamic range of your sensor. This then reverts the exposure of the image back to what the camera's metering originally proposed. The camera's metering will already give a good result in most cases, but in those cases where it doesn't, you can make a manual adjustment on the exposure module slider to set your midtones to an optimum point, and then use filmic to deal with the highlights and shadows. Alternatively, if you are doing display-referred workflow, you can use the exposure module to set your scene white point to match your display white point, and use something like base curve to adjust the rest of the tones. This is the basic idea behind the "compensation camera exposure" feature of the exposure module. On Thu, 5 Nov 2020 at 14:56, Terry Pinfold <terry.pinf...@utas.edu.au> wrote: > > > Hi Matt, > I was having a few images come up too dark but having uncheck the > "compensate camera exposure" box gives Filmic a more expected behaviour. I > am not sure why that option even exists as I expect that if I use EV comp > on the camera, I want EV comp applied not removed. > > Thanks for the tip. > ------------------------------ > *From:* Matt Maguire <matthew.magu...@gmail.com> > *Sent:* Thursday, 5 November 2020 2:15 PM > *To:* David Vincent-Jones <david...@gmail.com> > *Cc:* darktable forum <darktable-user@lists.darktable.org> > *Subject:* Re: [darktable-user] Compensate camera exposure > > If I take a photo where I bumped up the exposure compensation dial +1EV on > my camera to "expose the the right", then when I import the image, by > default exposure module adds the +0.5EV exposure, and takes off the +1EV I > added using the camera exposure dial, to give me a net -0.5EV exposure > adjustment. If I uncheck the "compensate camera exposure" box, then the > picture brightens up by +1EV, no longer compensating for that +1EV I > dialled in to the camera when I took the shot. > > So, it all seems to work as expected. Do you see something different? How > are you getting that automatic increment of +1.25EV? That's not in the > code, so it must be an auto-apply preset you have defined. Did you have the > "compensate camera exposure" box ticked when you defined the preset? If > not, then the preset will not activate this compensation. > > > On Thu, 5 Nov 2020 at 12:37, David Vincent-Jones <david...@gmail.com> > wrote: > > Exposure on my RAW files is automatically incremented by 1.25 EV (Fujifilm > camera) as a result of the current filmic auto operation. I have in > addition checked the box for an adjustment based on "compensate camera > exposure". These 2 EV adjustment should be cumulative but currently the > second adjustment is not being applied. > > Anybody else seeing this? > > David > > ____________________________________________________________________________ > darktable user mailing list to unsubscribe send a mail to > darktable-user+unsubscr...@lists.darktable.org > > > ____________________________________________________________________________ > darktable user mailing list to unsubscribe send a mail to > darktable-user+unsubscr...@lists.darktable.org > > > > University of Tasmania Electronic Communications Policy (December, 2014). > This email is confidential, and is for the intended recipient only. > Access, disclosure, copying, distribution, or reliance on any of it by > anyone outside the intended recipient organisation is prohibited and may be > a criminal offence. Please delete if obtained in error and email > confirmation to the sender. The views expressed in this email are not > necessarily the views of the University of Tasmania, unless clearly > intended otherwise. > ____________________________________________________________________________ darktable user mailing list to unsubscribe send a mail to darktable-user+unsubscr...@lists.darktable.org
