In today’s world of photographic digital processing and editing, RAW adjustments offer some of the most important and powerful capabilities. RAW processing tools provide a launching pad for the direction we can take our images. What we run into though is that when these tools get as powerful and complex as they have, we have to develop different workflows for different kinds of image creation, and High Dynamic Range images are no exception.

RAW processing software applications have numerous luminosity and color adjustments along with tools designed to help remove artifacts like noise, chromatic aberrations, lens vignettes, and so on. When we process a single image in a RAW software application, we can take advantage of many, if not all, of these tools to optimize and develop the photograph the way we want. Special care needs to be taken however when processing RAW files with the intent to merge them into a single HDR image.

When processing RAW files for HDR, it is important that all of the adjustments made are consistent between each exposure. If any of the tools are adjusted inconsistently, it can throw off the High Dynamic Range software and can produce unexpected and often unwanted results. Additionally, there are only a limited number of adjustments we recommend to be made to RAW files intended for HDR.

Those adjustments are:

- White Balance
- Tone Curve
- Noise Reduction
- Input Sharpening
- Lens Correction (including CA correction)
- Dust Removal
- Camera Calibration settings (if used)

It is also generally suggested not to adjust any of the other luminosity or saturation controls for images that will be merged together. When merging an exposure series of photos together, the goal is to access all of the information that is within each of the individual exposures. Therefore, it is not necessary to adjust the brightness, contrast, or saturation within each of the individual images. Furthermore, adjusting the brightness, contrast, or saturation can even result in lower quality results than leaving those settings at a neutral position.

Using these suggested RAW corrections will allow you to create the best possible HDR merge.  Lets take a look at the available tools and controls available in each of the different RAW processing softwares.

Photoshop/Adobe Camera RAW:

If you use Adobe Camera RAW for your RAW processing, here is the interface along with the suggested tools highlighted.

To make sure all of the adjustments in RAW are consistent with each other, click on the image that you will base your white balance adjustments on (usually the exposure closest to what the camera metered as “correct” works best). Hold “Shift” on your keyboard and click on the rest of the exposures.  This will highlight the images and automatically synchronize them when you make adjustments.

Adjustments to make:

1. White Balance: If the white balance of the image is not ideal straight out of camera, adjust it as you see fit. For best quality, set the white balance as close to neutral as possible. If you wish to warm or cool the color of the photo, you can control that after the HDR merge, within the HDR editing software.

2. Tone Curve: Set the tone curve to “linear”. This is very important when the individual images are merged together. The HDR software attempts to remove any contrast, to “linear-ize” the file. Contrast added by a tone curve applied in the RAW process to the individual exposures can negatively affect the quality of the merged image.

3. Noise Reduction and Input Sharpening: Both of these tools are found in the same module of Adobe Camera RAW.  They are designed to help remove noise artifacts, and to add input sharpening to retrieve a little bit of detail from the initial capture. Applying noise reduction can be very beneficial when merging HDR exposure series together.  In the process of merging images together to create an HDR photo, the appearance of noise can be amplified.  By getting rid of the noise in the initial RAW process, you will not have to deal with removing the noise later on in the processing. If you choose to do selective noise reduction, we recommend Dfine 2.0.

4. Lens Corrections: Using lens corrections can help to fix distortion, vignettes, and chromatic aberrations specific to individual lenses, or they can be adjusted manually. Vignettes and chromatic aberrations can be amplified in the creation of HDR images so getting rid of it before the merge can help to create a higher quality end result.

5. Dust Removal: This tool is not accessed through the right hand side tools panel, but in the top tool bar. If you have dust spots on your censor they can be removed before merging the HDR image.

6. Camera Calibration: Custom camera calibration can be very beneficial for helping to create the best HDR image, or for that matter, any image.  Using a tool such as X-Rite ColorChecker Passport can help get the most out of each exposure.

Lightroom:

If Lightroom is your RAW processing software of choice, the adjustment tools are found in the Develop module on the right hand side of the interface.

To make sure all of the RAW adjustments are consistent, click on one of the “end” images in your exposure series (either the furthest left of furthest right), hold the “shift”  key on your keyboard and click on the other “end” image. This process will highlight the images and automatically synchronize them when for when you make adjustments. Start with your White Balance adjustments by clicking on the exposure closest to what the camera metered as “correct”, this will most often times yield you the best results.

1. White Balance: If the white balance of the image is not ideal straight out of camera, adjust as you see fit. For the best quality, set the white balance as close to neutral as possible. If you wish to warm or cool the color of the photo, you can control that after the HDR merge, within the HDR editing software.

2. Tone Curve: Set the tone curve to “linear”. This is very important when the individual images are merged together the HDR software attempts to remove any contrast, to “linear-ize” the file. Contrast added by a tone curve applied in the RAW process to the individual exposures can negatively affect the quality of the merged image.

3. Noise Reduction and Input Sharpening: Both of these tools are found in the same section of the Develop Module.  They are designed to help remove noise artifacts, and to add input sharpening to retrieve a little bit of detail from the initial capture. Applying noise reduction can be very beneficial when merging HDR exposure series together.  In the process of merging images together to create an HDR photo, the appearance of noise can be amplified.  By getting rid of the noise in the initial RAW process, you will not have to deal with removing the noise later on in the processing. If you choose to do selective noise reduction, we recommend Dfine 2.0.

4. Lens Corrections: Using lens corrections can help to fix distortion, vignettes, and chromatic aberrations both specific to individual lenses, or they can be adjusted manually. Vignettes and chromatic aberrations can be amplified in the creation of HDR images, so getting rid of it before the merge can help to create a higher quality end result.

5. Dust Removal: To access the Clone and Healing tool in Lightroom, click on the circle with the arrow pointing to the right, you will find it just below the histogram in the upper right hand corner of the Lightroom Develop module interface.

6. Camera Calibration: Custom camera calibration can be very beneficial for helping to create the best HDR image, or for that matter, any image.  Using a tool such as X-Rite ColorChecker Passport can help get the most out of each exposure.

Aperture:

If you use Aperture as your host software to process your RAW files, you can find all of the tools available in the Adjustment section on the left hand side of the Aperture interface.

To make sure all of the RAW adjustments are consistent, click on one of the “end” images in your exposure series (either the furthest left of furthest right), hold the “shift” key on your keyboard and click on the other “end” image. This process will highlight the images and automatically synchronize them when for when you make adjustments. Start with your White Balance adjustments by clicking on the exposure closest to what the camera metered as “correct”, this will most often times yield the best results.

1. White Balance: If the white balance of the image is not ideal straight out of camera, adjust as you see fit. For best quality set the white balance as close to neutral as you can. If you wish to warm or cool the color of the photo you can control that after the HDR merge, within the HDR editing software.

2. Tone Curve: Set the tone curve to “linear”. This is very important when the individual images are merged together the HDR software attempts to remove any contrast, to “linear-ize” the file. Contrast added by a tone curve applied in the RAW process to the individual exposures can negatively affect the quality of the merged image.

3. Noise Reduction:  Applying noise reduction can be very beneficial when merging HDR exposure series together.  In the process of merging images together to create an HDR photo, the appearance of noise can be amplified.  By getting rid of the noise in the initial RAW process, you will not have to deal with removing the noise later on in the processing. If you choose to do selective noise reduction, we recommend Dfine 2.0.

4. Input sharpening: Input sharpening can help get a little bit of detail back from the initial capture to the RAW processing.

5. Devignettes and Chromatic Aberrations: Because vignettes and chromatic aberrations can be amplified in the creation of HDR images, getting rid of them before the merge can help to create a higher quality end result.

6. Dust Removal: If you have dust spots on your censor they can be removed before merging the HDR image.