The Image Editor tab in Single Editor Tab Mode - Vertical Tabs (SETM) in RawTherapee 5.

The Image Editor tab is where you tweak your photos. By default RawTherapee is in "Single Editor Tab Mode, Vertical Tabs" (SETM) which is more memory-efficient and lets you use the Filmstrip (described below). You can switch to "Multiple Editor Tabs Mode" (METM) by going to "Preferences > General > Layout", however each Editor tab will require a specific amount of RAM relative to the image size and the tools you use, and also the Filmstrip is hidden in this mode, so we recommend you first give SETM a try.

1 The Preview Panel

The central panel holds a preview of your photo. This preview is generated from the actual raw data by processing it according to the settings either you manually set, or those that are stored in the processing profile used when opening that photo, as specified in "Preferences > Image Processing > Default Processing Profile". The preview will show you the effect of all the adjustments you make. Note that the effects of some tools are only accurately visible when you are zoomed in to 1:1 (100%) or more. These tools are marked in the interface with a "1:1" icon Zoom 100 identifier icon next to the tool's name.

The image you see in the preview is taken from the working profile's color space and converted into the monitor profile's color space, if a monitor profile is loaded, or into sRGB if one is not. It does not take into account the "Output Profile" section of the "Color Management" tool.

1.1 Eek! My Raw Photo Looks Different than the Camera JPEG

After opening a raw photo you will notice that it looks different, often worse - darker, less sharp, more dull, lacking contrast, more noisy - than your camera's JPEG, or than the same raw photo when viewed in other software. What gives? Witches, aliens, possums, or by design?

There are three things you must know first to understand what is happening here:

  1. Your camera does not show you the real raw data when you shoot raw photos. It processes the raw image in many ways before presenting you with the histogram and the preview on your camera's digital display. Even if you set all the processing features your camera's firmware allows you to tweak to their neutral, "0" positions, what you see is still not an unprocessed image. Exactly what gets applied depends on the choices your camera's engineers and management made, but usually this includes a custom tone curve, saturation boost, sharpening and noise reduction. Some cameras, particularly low-end ones and Micro Four-Thirds system, may also apply lens distortion correction to not only fix barrel and pincushion distortion but also to hide severe vignetting problems. Most cameras also underexpose every photo you take by anywhere from -0.3EV to even -1.3EV or more, in order to gain headroom in the highlights. When your camera (or other software) processes the raw file it increases exposure compensation by the same amount, making the brightness appear correct and hoping to recover some highlights in the process. RawTherapee shows you the real raw data which may mean your photos appear dark, so it is up to you whether you apply the required exposure increase and how you go about doing so, whether by using the Exposure Compensation slider or one of the various tone curves. Increasing exposure compensation makes noise more apparent regardless whether it is your camera or RawTherapee which does it, but other than this [b]RawTherapee does not "add noise"![/b] Many cameras apply noise reduction to the JPEGs (behind your back) to lower the noise level after increasing the exposure compensation, so you should expect there to be a difference between your out-of-camera JPEG and RawTherapee's image if noise reduction in RawTherapee is not enabled.
  2. Every DSLR raw file contains a processed JPEG image. Most raw files contain a JPEG image of the same full resolution as your camera can shoot, and some raw files contain as many as three JPEG images differing only in resolution. When you open raw files in other software, what you are usually seeing is not the raw data, but the embedded, processed JPEG image. Examples of software which are either incapable of or which in their default settings do not show you the real raw data: IrfanView, XnView, Gwenview, Geeqie, Eye of GNOME, F-Spot, Shotwell, gThumb, etc. It is worth mentioning at this point that if you shoot in "RAW+JPEG" mode, you are in fact wasting disk space and gaining nothing for it, as your raw files already contain the embedded JPEG files which you can view using the listed programs. The embedded JPEG may differ from an 'external' one as saved using "RAW+JPEG" mode in compression.
  3. Most raw development programs (programs which do read the real raw data instead of just reading the embedded JPEG) apply some processing to it, such as a base tone curve, even at their most neutral settings, thereby making it impossible for users to see the real, untouched contents of their raw photos. Adobe Lightroom is an example. Comparing RawTherapee's real neutral image to a quasi-neutral one from these other programs will expose the differences.

RawTherapee, on the other hand, is designed to show you the real raw image in the main preview, leaving the way you want this data processed up to you. When you use the "Neutral" processing profile you will see the demosaiced image with camera white balance in your working color space with no other modifications. You can even see the non-demosaiced image by setting the demosaicing option to "None". To provide you with a more aesthetically pleasing starting point, we do ship a collection of processing profiles with RawTherapee. After installing RawTherapee, the default profile for processing raw photos is eponymously called "Default". We also ship the "Default ISO Medium" and "Default ISO High" profiles which are designed to give a good starting point to moderately noisy and very noisy images, respectively.

None of the shipped profiles (at least none of the ones shipped in RawTherapee 4.2) are designed to imitate your camera's look. Why not? Every camera is different. My camera's image quality at ISO1600 could be far noisier than your camera's. My camera's response to colors differs from yours. Even the same camera can behave differently at various settings. To provide such profiles, we would need access to raw files for every supported camera model, often multiple raw files in various shooting modes for a single camera, and countless person-hours. This may be possible as a community effort, but it is not a job for a small team. Even then, of what purpose would RawTherapee be if you ended up with a camera JPEG look?

It is far more reasonable that you learn how to use the powerful tools that RawTherapee provides to get the most out of your raws, to surpass the camera look.

As of September 2015 we are starting to ship DCP input profiles made using DCamProf which include an optional tone curve. This curve is modeled after Adobe Camera Raw's default film curve and renders a result similar to your "camera look". The reason we include the curve in new DCP profiles is because it makes for a good vibrant starting point (as opposed to the flat look of using the "Neutral" processing profile) without having to use Auto Levels and without having to touch any of the other tools, and it is entirely optional. Do read the article on input profiles. If we ship a DCP for your camera model which includes the tone curve, the "Tone curve" checkbox in Color Management > Input Profile > DCP will be clickable. Applying the (Neutral) processing profile will disable the tone curve. While the input color profile is applied at the first stages of the toolchain pipeline, the DCP tone curve is applied later in the pipeline at some point after the Exposure tool.

You can create a processing profile ideally tailored to your camera and lens combination, and set RawTherapee to use it by default on your raw photos. See the Creating processing profiles for general use article to learn how.

1.2 Preview Modes

In addition to the normal preview, RawTherapee supports a number of other preview modes to help you tweak your photos. Preview modes are controlled via buttons in the Editor toolbar or via keyboard shortcuts. Only one preview mode can be engaged at a time.

* The preview is returned to normal by deselecting any other mode.
Preview Mode Shortcut Button
Regular* Preview mode 1 regular.png
Red channel r Preview mode 2 red.png
Green channel g Preview mode 3 green.png
Blue channel b Preview mode 4 blue.png
Luminance channel v Preview mode 5 luminance.png
Focus Mask Shift+f Preview mode 6 focus.png

The following preview modes are currently supported:

  • Red channel,
  • Green channel,
  • Blue channel,
  • Luminosity, which is calculated as 0.299*R + 0.587*G + 0.114*B,
  • Focus mask, to see which areas are in focus

1.2.1 Red, Green, Blue and Luminosity Preview Modes

When clipping indicators are engaged in the RGBL preview modes, shadow clipped areas are indicated in a blue color and highlight clipping is indicated in red. As during normal preview, the lightness of the clipping highlight is indicative of the degree of clipping.

Preview of individual channels may be helpful when editing RGB curves, planning black/white conversion using the channel mixer, evaluating image noise, etc. Luminosity preview is helpful to instantly view the image in black and white without altering development parameters, to see which channel might be clipping or for aesthetic reasons.

1.2.2 Focus Mask

Focus mask indicating the focusing plane

The focus mask is designed to highlight areas of the image which are in focus. Naturally, focused areas are sharper, so the sharp areas are being highlighted. The focus mask is more accurate on images with a shallow depth of field, low noise and at higher zoom levels.To improve detection accuracy for noisy images evaluate at smaller zoom, around the 10-30% range. Note that the preview is rendered more slowly when the focus mask is enabled.

The current implementation analyzes the preview image which is rescaled from the original captured size. This process of rescaling reduces the noise and is helpful to identify truly sharper details rather than noise itself which may also contain micro texture. At the same time, rescaling of the original image to the preview size compresses larger scale details into a smaller size, and it may introduce aliasing artifacts, both of which could lead to false positives. You can increase your confidence by viewing the mask at various zoom levels. It is not always fault proof, but can be helpful in many cases.

Warning: Be sure to double-check your images if you decide to delete them based on the focus mask.

1.3 Background color of the preview

The background color of the preview panel surrounding the image area may be changed to ease image preview during editing and to better visualize image cropping. A vertical stack of three thin buttons in the preview modes toolbar above the image preview panel allows to set the background color of the area around the photo preview.

Shortcut Button Preview Background
and Crop Visualization
Theme-based 8 Previewback 7 theme.png Previewback flower theme.png The cropped area of the image is masked with a theme-based color. The cropped area visibility is based on the crop mask color and transparency as set in "Preferences > Default Theme > Crop mask color/transparency".
Black 9 Previewback 8 black.png Previewback flower white.png The cropped area of the image is masked with black.
White 0 Previewback 9 white.png Previewback flower black.png The cropped area of the image is masked with white.

1.4 Detail Window

The "New detail window" button New-detail-window.png, situated below the main preview next to the zoom buttons, opens a new viewport over the main preview of an adjustable size and of adjustable zoom. This lets you work on the photo zoomed-to-fit while examining several areas of interest at a 100% zoom (or even more). The benefit of using this feature is particularly important to users with slower machines, though not only them, as the zoomed-out main preview takes a shorter amount of time to update than if you were to zoom it to 100% because working at a zoom level less than 100% excludes certain slow tools, such as Noise Reduction, while the little detail windows zoomed to 100% do include all tools and are fast to update because of their small size. This allows you can use the main preview for your general exposure tweaks where it is necessary to see the whole image, and one or more detail windows to get sharpening and/or noise reduction just right.

1.5 Preview refresh delay

Changing any tool's parameters sends a signal for the preview image to be updated accordingly. Imagine what would happen if there was no "delay period", and you dragged, for example, the exposure slider from 0.00 to +0.60. A signal would be sent to update the preview for every single change of that value - for +0.01, +0.02, ... +0.59, +0.60. Updating the preview 60 times would be completely unnecessary and actually take longer than it takes you to move the slider. This is especially true for more complicated tools, such as noise reduction, where a preview update can take even a second (depending on your CPU and preview size). The solution is to introduce a very short delay during which parameter changes are ignored, and the signal to update the preview is sent only after no parameter change has been registered after this time.

We have introduced two such paramters:

Default value = 100ms.
This is the minimum time to wait before the preview is refreshed.
Default value = 200ms.
This is the maximum time to wait before the preview is refreshed. If you keep changing a parameter, RawTherapee will not wait longer than this short time period before triggering a preview refresh. While the minimum delay is there to prevent overloading your CPU with unnecessary preview refreshes, this delay is to guarantee that you can see what happens to the image as you slowly change some parameter.

You can adjust both of these values in the options file in the config folder.

2 The Left Panel

To the left is a panel which optionally shows the main histogram ("Preferences > General > Layout > Histogram in left panel"), and always shows the Navigator, History and Snapshots. You can hide this panel using the Hide left panel icon hide icon, or its keyboard shortcut.

2.1 Main Histogram

Scaling turned off, the spike makes seeing the lesser tones impossible.
Scaling turned on, the spike's tip is scaled down to let you see the lesser tones.
Histogram of the input raw image. We can see there is no clipping in this image and that it is underexposed by a stop.
The RGB Indicator points out the position in the histogram of the R, G, B and L values of the pixel your cursor is hovering over.

The main histogram can show the histograms of the red File:HistRed.png, green File:HistGreen.png, blue File:HistBlue.png, CIELab Luminance File:HistValue.png and Chromaticity File:HistChro.png channels of the photo as it would look if you saved it. Use this information to prevent clipping in your end result. If the raw image has no clipping but the end result does, you can easily identify the channel(s) that need adjusting and take the needed steps to prevent it, if it is undesirable.

It can show you the histogram of the raw data File:HistRaw.png before any transformations such as demosaicing are applied to it. Use this information to see whether there is any clipping in the raw image. Clipped raw data cannot be recovered. Some clipped highlights can be reconstructed using the Color Propagation method.

When there is a disproportionately bright area relative to the rest of the image, this will show up as a spike in the histogram. If you want to show this on a linear histogram, unscaled in the y-axis, you will sacrifice seeing the low levels in order to fully show the spike. You can toggle scaling of the histogram in the y-axis HistFull.png to help deal with this, then high values will be scaled down so that you may better see the rest of the histogram.

You can show or hide the RGB Indicator Bar File:HistBar.png, which is situated under the histogram and shows you the exact place on the histogram of the R, G, B or L values of the pixel your cursor is currently hovering over in the main preview.

The histogram can be moved to the left/right panel from "Preferences > General > Layout > Histogram in left panel".

The values the main histogram and Navigator panel shows are either those of the working profile, or of the gamma-corrected output profile. You can choose which you prefer in "Preferences > General > Use working profile for main histogram and Navigator".

2.2 Navigator

The Navigator panel shows a thumbnail of the currently opened image, and RGB, HSV and Lab values of the pixel your cursor is currently hovering over.

The values the main histogram and Navigator panel shows are either those of the working profile, or of the gamma-corrected output profile. You can choose which you prefer in "Preferences > General > Use working profile for main histogram and Navigator".

2.3 History

Under the Navigator it is the History panel. While editing a photo, all your actions are recorded in this History panel. By clicking on the different entries, you can step back and forth through the different stages of your work.

2.4 Snapshots

Under the History panel is a panel called Snapshots. Its use is in that you can save a snapshot of the photo with all the adjustments up to that point in time, and then proceed to further modify your photo to give it a different appearance, saving new snapshots at every moment you feel you might have reached a version of your photo worth saving. Once you have two or more snapshots, you can just click on them to flip through the different versions and stick with whichever one you like best. In the future, the snapshots will be saved to the PP3 sidecar file. For now, the history and snapshots are lost when you load a new photo in the Image Editor or close RawTherapee.

3 The Right Panel

To the right is a panel which optionally shows the main histogram and Processing Profiles selector ("Preferences > General > Layout > Histogram in left panel"), and always shows the Toolbox. You can hide this panel using the Hide right panel icon hide icon, or its keyboard shortcut.

3.1 Processing Profile Selector

The Processing Profiles drop-down list lets you apply bundled or custom processing profiles. See the File Paths article for information on where these processing profiles reside on your system.

Pay attention to the "Processing profile fill mode" button!

"Fill" mode Profile-filled.png
When the button is activated and you open a partial profile, the missing values will be replaced with RawTherapee's hard-coded default values.
For instance if you apply a partial profile which contains only sharpening settings, all of the remaining tools (such as Exposure, Tone Mapping, Noise Reduction, Resize, etc) will pop into their default positions.
"Preserve" mode Profile-partial.png
If the button is deactivated and you open a partial profile, only those values in the profile will be applied, and the missing ones remain unchanged.
For instance if you apply a partial profile which contains only sharpening settings, only those sharpening settings will be applied, and your other tools remain unchanged.

The state of this button will make no difference if you apply a full profile, but most of the profiles bundled with RawTherapee are partial (for good reason).

3.2 Toolbox

The Toolbox, in the right panel, contains all the tools you use to tweak your photos. Each tool has its own RawPedia article.

4 Editor Tab Modes

RawTherapee allows you to work on photos in two modes:

  • Single Editor Tab Mode (SETM), where you work only on one photo at a time, and each photo is opened in the same Editor tab. There is a horizontal panel called the Filmstrip at the top of the Editor tab showing the rest of the photos in that folder for easy access. There are Previous Image and Next Image Nav-prev.png Nav-next.png buttons in the bottom toolbar (and keyboard shortcuts for them) to switch to the previous/next image.
  • Multiple Editor Tabs Mode (METM), where each photo is opened in its own Editor tab. The Filmstrip is hidden in this mode and there are no previous/next buttons. Having multiple photos opened at the same time requires more RAM.

Try both modes and see which one suits you best. To do that, click on the Preferences icon Preferences icon in the bottom-left or top-right corner of the RT window, choose "General > Layout" and set Editor Layout to your preferred choice.

Use this Preferences window to select a different language for the user interface, to choose a different color theme, change the font size, etc.

It is also possible to start RawTherapee in no-File-Browser-mode (without the File Browser tab) by specifying RawTherapee to open an image from your operating system's file browser (in other words, right-click on a photo and select "Open With > RawTherapee"), or by using the image filename as an argument when starting RawTherapee from the command line (rawtherapee /path/to/some/photo.raw). This mode was introduced for people with little RAM as not having a File Browser tab means RawTherapee uses a little less memory, however in practice the amount of memory saved is little and the usability cost outweighs the little benefit, so it is likely to be removed in the future (see issue 2254).

5 The Filmstrip

RawTherapee-4.2 showing the Filmstrip with the toolbar visible, which takes up more screen space but lets you easily label, rate and filter the visible thumbnails.
RawTherapee-4.2 showing the Filmstrip with the toolbar hidden, which makes it less high and provides more screen space for the main preview (partially visible at the bottom).

If you use Single Editor Tab Mode ("Preferences > General > Layout") you can display a horizontal panel above the preview, this is called the Filmstrip. It contains thumbnails of all images in the currently opened album, and is synchronized with the currently opened image so that you can use keyboard shortcuts or the previous Open previous image icon and next Open next image icon image buttons to open the previous/next image without needing to go back to the File Browser tab.

As of RawTherapee version 4.2.10, you can hide the Filmstrip's toolbar to save screen space. There are two ways of doing this: one way just toggles the toolbar on/off without resizing the filmstrip to the new height, and the other way does the same but also automatically resizes the filmstrip's height. Both are invoked via keyboard shortcuts only. As resizing the filmstrip's height will trigger a refresh of the image preview and this might take a while if using CPU-hungry tools like noise reduction while zoomed in at 100%, the mode that doesn't resize has been implemented for users with slow machines. Users with fast machines will find the auto-resizing mode more helpful.

6 Monitor Profile and Soft-Proofing

The widgets under the main preview in RawTherapee 5 allow you to apply a monitor color profile to the preview image. This enables users who have calibrated and profiled their monitors to get an instant and accurate preview of their work, whether you're staying in sRGB or working in a wide gamut. Note: OS X users are limited to sRGB and will not get an accurate preview otherwise (see discussion), while users of Linux and Windows will get a correct wide-gamut preview.

Go to Preferences > Color Management and point the "Directory containing color profiles" to the folder into which you saved your monitor ICC profile. Restart RawTherapee for the changes to take effect. Now you will be able to select your monitor's color profile in the combo-box under the preview. Use the "Relative Colorimetric" rendering intent unless you have a good reason otherwise.

One can also enable soft-proofing of the preview. This will show you what your image will look like once it gets transformed by the output profile in the "Color Management" tool. If you want to adjust an image for printing and you have an ICC profile for your printer-paper combination you could set that as your output profile, enable "Black point compensation" so that the blackest black in your image will match the blackest black your printer-paper combination is capable of reproducing, then enable soft-proofing. You will see what your image will look like if you print it. This allows you to make adjustments and get an instant preview of the result, saving you time and ink on test prints.

You should have a calibrated and profiled monitor in order for the soft-proofing preview to be accurate.

The items you see in the monitor profile combobox (under the main preview) and in the output profile combobox (in the Color Management tool) are ICC files located in a folder which you can point RawTherapee to by going to "Preferences > Color Management > Directory containing color profiles".