Documentation / easyHDR 3 Quick Start Tutorial

1. Taking photographs for a HDR

Take a set of photos of the same High Dynamic Range scene at different exposure times, ISO values or f-stops. In order to achieve best results the Exposure Value difference between the photos should be 1 to 2 EV. In most cases 2-3 such photos are enough, but it depends on the actual dynamic range of the photographed scene and on what you want to achieve (example of very high dynamic range scene that spans 9 EV).

EasyHDR can import JPEG/JPEG2000, HEIF/HEIC, RAW (eg. CR2, CR3, RAF, NEF, PEF, DNG, GPR, ARW, ORF, etc.), 8/16 bit TIFF, PNG and FITS file formats. Additionally it can also import HDR formats like: OpenEXR, Radiance RGBE and 32-bit TIFF.

The best way to take a HDR sequence of photos is to use Auto Exposure Bracketing feature in your camera. It allows taking a series of differently exposed photos fast enough to minimize later problems with image alignment even if you take the photos hand-held. Taking photos fast reduces also probability of ghosting effects. If your camera does not have the AEB feature you should consider using a tripod and rather avoid scenes where photographed objects move too much (many people, windy, etc.).

The camera sensors are getting better and less noisy, so in many cases a single JPEG, or better a single RAW image, is a good input for HDR-style processing.

2. Loading photos into easyHDR

Load the HDR photo sequence by dropping the files on easyHDR program icon which you can find on your desktop, by dropping them on the already running easyHDR's workspace, or click the "New" button to open file import dialog and select there the whole set of images.

You can also setup easyHDR as an external editor in other photo processing software. Finally, thanks to included Adobe Lightroom plug-in, you can do the whole job from the Lightroom level (for more information please refer to easyHDR User Manual).

Instead of processing a HDR image sequence, you can load just a single photo and do "LDR enhancement". This yields best results if the single photo has low noise level (better camera, shorter exposure, lower ISO) and is not too much under or overexposed. Please also note that the RAW photos do contain more dynamic range than a JPEG taken from the camera.

3. Importing and developing RAWs

EasyHDR uses LibRAW in order to import and develop the RAW photos. When RAWs are loaded, the import dialog is shown allowing to define the development options which include the white balancing, brightness, contrast, output color space, noise filtering and even dark frame subtraction. When more than one image is being loaded at a time, you can select any of them for preview. It is possible to either use the same import settings for all, or define them individually.

4. Lens correction

Before making a HDR image it is possible to preprocess the input photos. The lens correction tool fixes the chromatic aberration, vignetting and lens distortion for known cameras and lenses. The correction coeffictients are taken from the LensFun database. The correction can be applied automatically, or manually. It is advised to check the effects of correction using the manual tool when processing the certain camera-lens combination for the first time. For the lenses that are not yet supported, you can apply the correction manually using the simplest model. The manual approach is also useful when fixing distortions of fish eye lenses.

5. Image alignment

If the input photos are misaligned in respect to each other you may take advantage of the automatic, or manual alignment. Both are capable of compensating for shift, rotation as well as perspective misalignments. The manual tool may be used in a semi-automatic way. Just use the automatic pin placement option, then you can verify the quality of alignment on the preview and do corrections (should they be needed). The idea of manual alignment is simple - just select the base photo and place the pin pairs (each pair is marked with a different color) in a way that they point exactly the same details on the base picture (top left) as well as on the photo to be aligned to it (top right). The live preview is shown in the lower left window, but please note that all the pins must be placed before the good preview is shown. Repeat this operation for all photos to be aligned to the base.

In the majority of cases however, automatic alignment is sufficient. Just make sure that "Alignment -> Automatic" option is checked when HDR is generated.

6. Generating HDR image

After preprocessing the input photos you can generate the HDR image. At this stage there is a possibility to filter the image to reduce the noise.

Instead of generating a true HDR radiance map, you can merge the photo sequence using a pseudo-HDR algorithm (called Smart Merge), or to generate an image stack (simple average).

7. Ghost removal

The True-HDR method has a ghost effect removal capability. When the option is chosen, the ghost removal tool window appears before the HDR is generated. The user is supposed to paint masks that should cover the ghosted areas. Those areas are repaired by using just one, user-selected photo to reconstruct the HDR image (each photo has its own color assigned).

8. Image transformations

At any step of processing - right after image loading, during tone mapping, or even at post-processing, it is possible to apply basic image transformations like: rotation, flip and crop. In rotate & crop mode it is possible to fine tune rotation - to precisely level the image and the distortion along with perspective in two axes - to modify the shape of the image (for example to straighten the horizon, or vertical building walls, etc.).

9. Tone mapping

After the HDR image is generated, the mode is switched to tone mapping. Now you can try various settings in order to get the result you want - presets are good starting points. The preview is available at full image resolution.

Optionally, you can create layers that mask parts of the image. Each layer has a different tone mapping settings. That gives much more flexibility, allowing to differently treat various parts of the photograph. For example, you can make the clouds in the sky look more dramatic, while keeping the features in th ground level more natural. All the tone mapping settings apply per layer, meaning that even sharpening and white balance can vary. The mask painting is possible with a brush that can automatically (intelligent mode) adjust its opacity to the target's levels (stroke start point). Also the gradient painting tool is very powerful and allows live previewing before being applied.

Each change in the tone mapping parameters and also of the layers' masks is stored in history and can be undone or redone. You can view the history log by switching the left-hand tab.

10. Cloning & healing

The Clone & Healing tool, which can be used any time at the tone mapping stage, allows removing dust grains and the unwanted objects from your photographs. That makes easyHDR a complete tool, which allows you to create quality photos that do not need post processing with other software. For more information on using it please go to the User Manual.

11. Color adjustment

Apart from tone mapping settings that give you ability to control local and global contrast, there is also possibility to tweak color tone of the photograph. You can modify saturation selectively in respect to hue and brightness. It is also possible to fix white balance by setting color temperature and tint.

12. Postprocessing

Before saving the result you may wish to process the photo using available filters - blur, sharpening, noise removal (median and bilateral), or sample/target balance.

13. Saving the result

You can save the result after post processing it at "Step 3", or any time at "Step 2" - the post processing step is not necessary.

For best quality choose to save as 16 bit TIFF. You can also export the result to another image processing application. Just use the "Export to external editor" option.

EasyHDR allows to save your project at step 1 or 2. The project is saved into an easyHDR-specific format EHPX. The file contains the pre-processed (aligned and lens-corrected) input photos, the HDR generation settings (including the ghost mask), the layers and the tone mapping settings. You can re-load the project to alter your photo processing, or to continue processing, if you couldn't finish it earlier. The post processing applied at "Step 3" is not stored witin the project file.