faq: add Q&A about dynamic range/highlight/HDR modes

content/about/faq.md

@@ -11,18 +11,23 @@ menu: "footer"
 
 ## New Users
 
-### <a name="faq-lightroom"></a>Is darktable a free Lightroom alternative?<a href="#faq-lightroom" class="anchor" title="Link to this FAQ entry">¶</a>
-No. Other than both being raw editors with DAM features, and looking somewhat similar, they have very little in common. Darktable is a powerful and flexible raw processing toolbox, that leaves the user in charge of their workflow and provides a level of power and control that few others can match. This also means that the initial learning curve can be steep, since very little workflow and tool knowledge can be transferred from other programs.
+### <a name="faq-lightroom"></a>Is darktable a free Lightroom replacement?<a href="#faq-lightroom" class="anchor" title="Link to this FAQ entry">¶</a>
+No, darktable is an _alternative_, not a drop-in replacement. Other than both being raw editors with DAM features, and looking somewhat similar, they have very little in common. Darktable is a powerful and flexible raw processing toolbox, that leaves the user in charge of their workflow and provides a level of power and control that few others can match. This also means that the initial learning curve can be steep, since very little workflow and tool knowledge can be transferred from other programs.
+
+We have a [blog post](https://www.darktable.org/2024/12/howto-in-5.0/) to help you figure out how to do the equivalents of Lightroom actions in darktable.
 
 ### <a name="faq-camera-support"></a>Is my camera supported?<a href="#faq-camera-support" class="anchor" title="Link to this FAQ entry">¶</a>
 Please see the [camera support page](/resources/camera-support/).
 
 ### <a name="faq-file-support"></a>My camera is supported, but darktable can't open the photos<a href="#faq-file-support" class="anchor" title="Link to this FAQ entry">¶</a>
-Some file formats are not supported. The camera support page has a full list.
+Some file formats are not supported, as are some compression options for otherwise-supported formats. The camera support page has a full list.
 
 ### <a name="faq-initial-look"></a>Why doesn’t the raw image look like the JPEG?<a href="#faq-initial-look" class="anchor" title="Link to this FAQ entry">¶</a>
 This is explained [in the manual](https://docs.darktable.org/usermanual/stable/en/overview/workflow/process/#why-doesnt-the-raw-image-look-like-the-jpeg).
 
+### <a name="faq-very-dark"></a>No, I mean my images are **very** dark, not just dull
+If you are using Dynamic Range, Highlight Preservation, or HDR modes, your camera is deliberately underexposing the image by using a lower ISO than you've set (and is recorded in the image's metadata), and is relying on post-processing lightening to give a "normal"-looking image with better highlight definition.  darktable is unable to determine the corrections needed (which are proprietary and often in the form of a custom tone curve instead of simple EV correction), so [you will need to manually apply the correction](https://docs.darktable.org/usermanual/stable/en/overview/workflow/process/#why-doesnt-the-raw-image-look-like-the-jpeg).  For Fujifilm, DR200 mode needs an additional +1 EV exposure correction and DR400 mode needs +2 EV.  For Nikon Z-series cameras, HLG tone mode needs an additional +2 EV and probably some tone curve adjustment.
+
 ### <a name="faq-grey-interface"></a>Why is the interface so flat and grey?<a href="#faq-grey-interface" class="anchor" title="Link to this FAQ entry">¶</a>
 The default theme has been carefully designed to limit certain optical illusions that affect how brightness, contrast and saturation are perceived. Changing to a darker theme, in particular, can lead to images that are too dark or over-saturated. This is explained in detail in the manual [here](https://docs.darktable.org/usermanual/stable/en/module-reference/utility-modules/darkroom/color-assessment/), [here](https://docs.darktable.org/usermanual/stable/en/preferences-settings/general/) and [here](https://docs.darktable.org/usermanual/stable/en/overview/workflow/process/#edit-in-a-controlled-environment).
 
@@ -65,7 +70,7 @@ There is only one way, and that is "darktable". All lower case, in one word, exc
 For fast discussions and short questions it's best to visit us in IRC (on _irc.oftc.net_, channel #darktable), especially in the Western European evening hours. If you don't want to use IRC, don't know what it is or want something less transient you can use our mailing lists. See our [contact page](/contact). For Issues/bugs, please use [GitHub Issues](https://github.com/darktable-org/darktable/issues)
 
 ### <a name="faq-sigill"></a>darktable crashes with SIGILL. What's up?<a href="#faq-sigill" class="anchor" title="Link to this FAQ entry">¶</a>
-Due to the large number of mathematically intense operations which the Image Operators (IOPs) perform, the minimum requirement for a CPU to run darktable is one which supports SSE2. If your cpu does not support SSE2 more than fifteen years after the feature's introduction, then it really is time to upgrade. Please see [the Wikipedia page](https://en.wikipedia.org/wiki/SSE2) for more details on SSE2-capable CPUs.
+Due to the large number of mathematically intense operations which the Image Operators (IOPs) perform, the minimum requirement for an x86 CPU to run darktable is one which supports SSE2. If your CPU does not support SSE2 more than twenty years after the feature's introduction, then it really is time to upgrade. Please see [the Wikipedia page](https://en.wikipedia.org/wiki/SSE2) for more details on SSE2-capable CPUs.
 
 ### <a name="faq-tethering"></a>I attached and turned on my camera, but it doesn't show up in darktable, what's wrong?<a href="#faq-tethering" class="anchor" title="Link to this FAQ entry">¶</a>
 If the camera in question is supported by `libgphoto2`, then the most likely cause is that some other process is blocking the device.
@@ -87,7 +92,7 @@ In rare cases that might break other software accessing the camera though! If yo
 Yes, there are two libraries we heavily rely on:
 
 * **exiv2** is used for reading metadata from image files. If something isn't shown correctly in the [image information](https://docs.darktable.org/usermanual/stable/en/module-reference/utility-modules/shared/image-information/) panel on the left side then please check with the command line tool `exiv2` and report any problems upstream on [their bug tracker](https://github.com/Exiv2/exiv2/issues)&nbsp;– there isn't much we can do to fix those things ourselves.
-* **lensfun** is used for lens correction. If the [lens correction](https://docs.darktable.org/usermanual/stable/en/module-reference/processing-modules/lens-correction/) module isn't showing your camera or lens, or a wrong one, then please report that to [those folks](https://github.com/lensfun/lensfun).
+* **lensfun** is used for lens correction. If the [lens correction](https://docs.darktable.org/usermanual/stable/en/module-reference/processing-modules/lens-correction/) module isn't showing your camera or lens, try running `lensfun-update-data` to get the newest lens database.  If lens correction still does not show your camera/lens, or shows a wrong one, then please report that to [those folks](https://github.com/lensfun/lensfun).
 
 
 ## <a name="faq-linux"></a>Linux<a href="#faq-linux" class="anchor" title="Link to this FAQ entry">¶</a>