Merge to 32-bit HDR Tutorial


Welcome to Joshua Gunther's "Merge to 32-bit HDR Tutorial."  I have been doing HDR photography for several years now and I'm so excited to share my technique for HDR with you.  This is the main method I use with all of my HDR photography.  It is super simple and gets great results.  There are tons of techniques out there but this method will give you the best possible results 99% of the time.  

Don't believe me?

Take a look at my HDR Software Comparison for an example of why I think this HDR method is the best one of them all!

Lets get started.

Emerson Collge Before Emerson Collge After

What you will need for this tutorial:

  1. Camera-  that can shoot exposure brackets (automatically or manually)
  2. Tripod-  or something to keep the camera stable
  3. Lightroom 4- software from Adobe
  4. Photoshop CS6- software from Adobe
  5. Photomatix's Merge to 32-bit HDR Plugin- comes free with a copy of Photomatix Pro

Software Links:

  1. Lightroom 4:
  2. Photoshop CS6:
  3. Photomatix Pro:
  4. Merge to 32-bit Tiff Plugin:


Learn faster with video? Save a ton of time and learn with my Merge to 32-bit HDR Video Tutorial

It is assumed that in order to understand this tutorial you already have a basic working knowledge of Lightroom and Photoshop. I’m going to do my best to explain the basics, but a general knowledge of layers, layer masks, the adjustment brush, clone tool, and healing brush tools are required for this tutorial. If you don’t know these tools, please check out the Adobe website for help.
— Joshua Gunther

Note to the Pros:

If you are a professional and have been doing HDR photography for awhile, this tutorial can be boiled down into three easy steps.

1. Take your brackets, and export them to the Merge to 32-bit HDR Plugin installed in Lightroom 4. Adjust your new 32-bit HDR tiff file like you would any other raw file.

2. If needed, do any selective adjustments in Photoshop, i.e. selective sharpening, luminance masking, dynamic blending, clone stamping and clean up to finish things off. Thats it! Simple right?

This truly is the best method that I have found to do simple, clean, and natural looking HDRs. You will love it. If none of that made any sense to you, then follow along below for the step by step tutorial.

What does HDR stand for?

HDR stands for, "High Dynamic Range Imaging."  It is a technique that tries to increase the dynamic range on an image beyond what is normally possible by most imaging devices, and combines them into an image that better matches what our eyes see!

What the heck does that mean?

Normally when we look at the world around us our eyes are constantly adjusting to how bright or dark things are.  If we look up at the sky on a bright day our eyes adjust.  If we look over to a shady tree our eyes adjust to what is in the dark shade.  If I took a camera and tried to take a picture of both the sky and the shady spot under the tree, my camera would have a really hard time being able to capture both in the same shot.  It would most likely have to compromise the exposure of part of the scene--either the sky or the shady spot.  We see this all the time without even knowing it.

Have you ever tried to take a picture of a person with a deep blue sky in the background and when you look at the photo the person looks great but the sky is completely white? Where did the blue sky go? Or have you ever taken a picture of a gorgeous sunset, and the mountains in the background are completely black? That is because our cameras are limited with the amount of light they can see.

So why use HDR?

I use it because my camera CANNOT capture all of the light it sees in a single photo! In other words, my camera has a limited amount of "Dynamic Range" that it can capture.  HDR is a process that tries to combine more light information into a single photo! This is why I use HDR!

Wait a second, people have been doing photography for a long time, why haven't I heard of HDR until now?

Photographers have been using all kinds of methods to try and get more dynamic range (or light) into their photos. They have used techniques including Neutral Density Filters, Digital Blending, Luminance Masking, and Dynamic Blending all of which can be used to achieve a larger dynamic range in your photographs.  But for me the Merge to 32-bit HDR method is simply the easiest way I have found to get the best results with the least amount of effort.  You will get beautiful, natural looking photographs that people will love, all in half the time you spend in other HDR programs or using other methods.  It is a great way to get the results you want quickly and easily.  You will love it!

Lets Get Started:

The Merge to 32-bit HDR technique I’m about to show you has given me the most consistent results out of all of the other techniques I have tried! This technique is the one I’m most excited to share with the world!
— Joshua Gunther

Step 1: Bracketing Exposures.

The first things we need to make an HDR image are "Bracketed Exposures."  Remember, the whole reason we are doing this is to capture as much light information as possible and blend it together.

Bracketing simply means taking the same picture, again and again at several different light levels (see the image above).  The most classic range of brackets are from -2 to +2.  The majority of the time capturing brackets in this range should give you good results.  There might be times when you need more brackets but for now lets concentrate on the method you will use most often.

I personally like to capture brackets in 1 stop increments for a total of 5/6 images: -2, -1, 0, +1, +2 (sometimes adding an extra -3 image if I need it).  Doing this gives me the most flexibility later on if I need to do any digital blending in photoshop.  You can, however, get away with only taking three images (-2, 0, +2) and achieve the same results but taking 5 has provided me with the most flexibility and is what I prefer.  Find out what works best for you and stick with it. [border]

My Basic Camera Setup:

This is how I set up my camera every time I bracket exposures!

  1. Camera on Tripod - for stability and to make it easier to line up brackets in the HDR program
  2. Camera set to Aperture Priority
  3. F-stop usually set to around f9-f16.  My default is f16, but if it is too dark to get all of my brackets in the 30 second exposure limit I'll start going down in f stop to compensate for the amount of light available.
  4. ISO set to as low as possible, usually in the range of 160-640.  On the 5D mkII it has been found that if you use either ISO 160, 320, 640, or 1250 you will get the least amount of noise in your images.
  5. Lens set to Manual Focus
  6. White balance set to Daylight, or Tungsten depending on time of day, (can be updated later in Lightroom).
  7. Focus checked and adjusted in "Live view" to prevent focus hunting while taking brackets! Really Important!
  8. HDR Bracketing turned on in Magic Lantern
  9. Mirror lockup- turned on
  10. 2 second timer turned on

This is my checklist every time I go out to take a bracketed image.  Using these settings, I have been able to get consistent results in almost any situation, every time.

One thing to mention about this checklist: When taking bracketed images it is really important that each bracket is as consistent, settings wise, to each other as possible.  That is why I try and remove as many automatic settings from the camera, even down to the auto focus.  With this setup the only thing that I'm letting the camera handle on its own is the shutter speed! Thats it! You will get much better results during post processing if the aperture, ISO, white balance, and focus of each image is the same--particularly the focus and aperture.  That is why I like to set my lens to manual focus and double check it in live view to insure my 5D mkII doesn't change focus between brackets by accident.  That way I can go home confident that I got the shot!

Capturing Brackets using a Canon 5D mkII

There are several ways to capture brackets.  I'm only going to cover how I do it on the Canon 5D mkII for this tutorial so be sure to look up how your camera does it in your owners manual.  For Nikon users look for the "BKT" button or HDR option in the shooting menu.  For Canon users what you are looking for is "AEB" or "Auto Exposure Bracketing."

Turning on AEB Option 1: 

Click on the menu button in the upper left of your camera, click over to the second menu screen and look for “Expo.comp./AEB.”  To turn this on, highlight the menu setting, and click the SET button.  Now in the AEB menu, turn the dial on top of the camera (next to the shutter button) to the right expanding your brackets.  As you click to the right you will see the brackets get farther and farther apart.  What your are looking for is to set your brackets to 1 Stop apart (See ref image).

Click menu button, go to second tab, click set button on "".

Once in this menu, turn the dial next to the shutter button to the right expanding your brackets to 1 stop apart.

Turning on AEB Option 2:

With the info screen visible on the back of the camera, click the multi controller button (small button above the large exposure comp. wheel).  Once something in the info menu is highlighted navigate to the exposure./AEB setting area and select, turn the dial on the top of the camera by the shutter button to the right.  You should start to see your brackets expanding in the highlighted area. Set them to 1 stop apart.

Option 3: My Preferred Method- Magic Lantern

Lately I have been using Magic Lantern firmware on my Canon 5D mkII.  There are some amazing HDR options built into Magic Lantern, most importantly the option to take as many brackets as you want automatically! This addresses the 3 bracket limitation that the 5D mkII has with the default firmware.  For ease of use this has been the best option I have found to date for HDR bracketing on the 5D mkII.

You can find out more information about Magic Lantern Firmware here: [border]

FYI- The Canon 5D mkII has a three bracket exposure limit, meaning you can only take three brackets at a time. In order to take 5 brackets we are going to have to get creative. Check out the steps below to get around this limitation.

Capturing 5 Brackets with a 3 Bracket Limit using 5D mkII: Step by Step (Without Magic Lantern)

Step 1.

Using the exposure compensation wheel, slide the brackets to the left to set up shooting the brackets for -2, -1, 0.  Click the shutter, with the 2 second timer ON, and you should see/hear your brackets being taken.

Step 2.

Once you have the first three, quickly slide the exposure compensation wheel to the right to take 0, +1, +2.  Click the shutter button to take the next three.

You should now have all of your brackets.  You will end up having an extra 0 exposure but you can always delete it later if you don't need it.

Now that we have some bracketed images, lets start post processing!

Learn faster with video? Save a ton of time and learn with my Merge to 32-bit HDR Video Tutorial

Post Processing 

Step 1: Import Brackets into Lightroom 4

Launch Lightroom 4, and click on the "Import" button in the lower left.  Often times if you plug in your memory card/camera, Lightroom will automatically launch the import dialogue.

Select your memory card in the upper left to find your photos

The Setting I like to use while importing my photos are:

  1. Copy to DNG- This converts the native Canon raw format to DNG.  This usually makes the file size smaller as well as converts it into a more archival format for later on down the road.
  2. I usually give my photos unique file names using the "Shoot Name-Original File Number."  In this case I have picked "sydney" and left the native file number the same as when it took it in the camera.
  3. I'll add key words to the group I'm adding.
  4. Select the folder you want to import too and click "IMPORT"

Use these settings in your "Import Dialogue" box.

Step 2: Pre-Export Adjustments

Before I export to the 32-bit HDR Plug-in I do a couple pre adjustments to my raw files.

To start I select all of my raw files and click on the "Develop" tab in the upper right and do the following adjustments.

  1. Check the white balance and adjust if needed.
  2. Go to "lens correction" and under "color" check "remove chromatic aberrations."
  3. Next in the same tab go to "profile" and check "enable profile corrections."   Define your camera model and lens.  Next slide the "Distortion Slider" all the way to the left.  If the distortion correct looks better to you then leave it on, but often times I like the look of the photo without it so I leave it off.
  4. Now with all of your brackets still selected, click on "sync" in the lower right and bring up the "synchronize" dialogue box.  Make sure "white balance," "lens corrections" and "process version" are all checked and click "synchronize."  

Select all of your brackets and click on the "develop" module to get started.

Go to the "lens corrections" tab and click on "color" submenu, and check "remove chromatic aberration"

Next go to the "profile" submenu, check "enable profile corrections" and select your camera lens.  Now slide the "distortion" slider all the way to the left.  This will remove the distortion correction but leave the vignetting correction for all of our brackets.

Click the "sync" button in the lower right corner and bring up the "synchronize settings" dialogue box.  Check the "white balance, lens corrections, and process version" and click "synchronize" down at the bottom.  This will make sure that all of your brackets have the exact same settings before you export to the 32-bit HDR plugin.

Now your ready to export.

Step 3: Export to Merge to 32-bit HDR Plug-in

Click on the "library" tab to get back to the library module. With all of your brackets still selected click on "export" in the lower left.

In the upper left of the export dialogue select "Merge to 32-bit HDR" from the preset menu.

The settings I like to use from this dialogue are:

  1. Image format: TIFF- this is an uncompressed format and insures that I'm not losing any data upon export.
  2. Color Space: AdobeRGB 1998 - This is the same color space that I have selected on my 5D mkII.  I want to keep this consistent with the same color space as my camera.
  3. Bit Depth: 16bit- This is the largest amount of bit information I can send to the plug.  Remember we want as much picture data as possible
  4. Metadata ALL: This helps transfer the same meta data that the original picture had to the new file we are about to create.


Merge to 32-bit HDR Dialogue

The settings I like to use are:

  1. Align images- by correcting horizontal and vertical shifts with "crop aligned result" turned OFF.  This setting has become the most consistent for me.  I have used "by matching features" before but sometimes the alignment had not been incorrect so I stopped using it.  If for some reason "horizontal and vertical shifts" doesn't work give this a try and see if you get better results.  Also the reason I turn "crop aligned result" off is because I want to be able to crop the image myself, rather then have the program do it.  This gives me more flexibility later on in the process.
  2. "Add Suffix": I always name my HDR's based on the process I'm using.  This way if I ever go back to the photo and want to remember how I processed it, I can quickly know.  In this case I have added "_32bit_PM_HDR" to remind me later that I used the merge to 32-bit HDR plug-in.
  3. Check "use half floating point format."  What this does is compresses the 32-bit tiff to a smaller file size.  With this unchecked, the file sizes are massive, but on the flip side your are insured that you get all of the floating point data into the file.  In the long run I have found that using the half floating point option has been fine and I haven't noticed a loss of data using it.
  4. Check "scale pixel values to fixed range."  What this does is averages the exposure of the floating point tiff to somewhere in the middle to provide you with a good starting point.  If for some reason the plugin gets the exposure level wrong, it can easily be fixed by adjusting the exposure slider in Lightroom back towards the original image you started.

Once all of these are checked click "MERGE" to start the export dialogue running.  In about a minute the 32-bit file will be ready for us to start working on our first 32-bit HDR

Wait a second, what the heck just happened and what is a 32-bit tiff file?

What we just did is simple.  We just took five raw files containing a ton of light and color information and we combined them into a new 32-bit floating point tiff MASTER RAW file.  This new raw file contains all of the information of the other exposures all into 1 master file.  It is like Lord of the Rings, there is one ring to rule them all.  This is one raw file that has all of the exposure information combined into it.

Why is this so cool?

Because you now have a ton more information to play with! Have you ever tried to make adjustments to your raw files but quickly realized you are limited with how much information you have to adjust? What if you had two more raw files worth of information on either side of that slider that you could use to bend the photo to your will? It would give you more control wouldn't it? That is what the 32-bit floating point tiff does.  It combines all of your exposures into one master raw that you can use to adjust.  How cool is that! [border]

Step 4: Adjusting 32-bit HDR in Lightroom 4's Develop Model

Now the fun part! Once your 32-bit tiff file is created you can now adjust it in the same way you would normally adjust any other raw file, just with more information.

  1. Click on the develop tab to launch the develop module.
  2. Adjust basic exposure settings.
  3. Check for any sensor dusk particles, and fix using the spot removal tool.
  4. Go to the detail tab and adjust sharpening and noise reduction.

Start by adjusting the sliders in the "basic" tab.

These are the settings I used.  Notice how much more control you have in the highlights and shadow areas of the photo! The new 32-bit tiff has given you a lot more information to play with.

Next go hunting for sensor dust, using the spot removal tool to remove any dust you might find!

All of the dust particles I found and fixed

 Go to the "detail" tab and adjust sharpening and noise reduction.

Step 5: Selective Adjustments- Adding contrast to the Opera House and adjusting exposure

We need to fix some issues with the Opera House.  Right now the sky and foreground look great but the Opera House has gotten a little bright and is a tad over exposed.  To adjust this I'm going to use the adjustment brush to fix it and add some more contrast to give it a little more pop.

  1. Select the adjustment brush in the upper right.
  2. Using the adjustment brush paint over the Opera house covering the area you want to fix.
  3. Select the "erase" brush and turn on "auto mask."
  4. Zoom into 1:1 and begin painting around the edge of the Opera House.

Start by Painting at 100% flow over the Opera House and completely cover it.  Be sure and go over all of the edges making sure they are completely covered.

Click on the Erase Brush and check Auto Mask

To make this faster, turn off the "detail," "lens corrections" and "effects" by clicking on the box to the left of the tab.  You will notice a huge performance increase in the adjustment brush with these turned off.  Just remember to turn them back on when your done!

  1. Remove the mask along the edge of the Opera House.  Remember to take your time doing this.  The better the mask the cleaner the results will be in the end. If you are sloppy with your mask, your photos will have weird edge halos and all kinds of weird artifacts from the selective adjustments you painted in.  If you want professional looking photos, take the time to do it right the first time! Zoom in close and be careful! The auto mask feature should make it easier to produce a clean edge.  If you make a mistake you can always paint over the edge again, and erase it until it is right.  Try and make it as perfect as possible.
  2. Now that you have the mask correct, adjust the sliders until it looks right to your eye.

Start painting carefully along the edge of the Opera House, removing the mask from the background.

Paint slowly and carefully.  Make it PERFECT.  :)

Final Mask should look like this!

Now that you have your mask, adjust the sliders to get the final result!

Learn faster with video? Save a ton of time and learn with my Merge to 32-bit HDR Video Tutorial

Step 6: Advanced Adjustments- Fixing ghosting issues in the 32-bit tiff File

Ok, I have gotten my image as close to final as possible but there are still a few problems with it.  I need to fix some ghosting from the ferry boats that were in some of my other exposures.  To do this I'm going to need to take this into Photoshop CS6 and use some of the advanced healing and cloning tools.

  1. Click on the "library" tab and leave the develop module.
  2. Right click on the 32-bit tiff and go to "edit in - edit in Adobe Photoshop CS6."
  3. Click "edit a copy with Lightroom adjustments."

Go to edit in - edit in Adobe Photoshop CS6

Edit a copy with Lightroom adjustments

Now that we are in Photoshop, I'm going to clean up those ghosting issues.

  1. Duplicate the background layer by dragging it on the "create a new layer" tab down at the bottom.
  2. Zoom into the ghosted area.
  3. Use the clone tool and other healing brush tools to fix the ghosting in the water

Starting view in Photoshop

Grab the layer and drag it over the create new layer button

Using the clone tool, start painting out the ghosted areas.

Ghost Removal Before and After

Ghost Removal Before and After

Highpass Layer for Sharpening

  1. Click Comand-ALT-SHIFT-E all at the same time.  This will create a new layer with all of the other adjustment underneath it.
  2. Go to filter-other-highpass.  I usually use a setting of 4 to begin.
  3. Go to layer-adjustments-desaturate- this removes any possible color data that might be present from the highpass filter.
  4. Change the blending mode of the layer to "overlay" to add the sharpening.
  5. Create a layer mask, and remove the sharpening from the sky and the water.
  6. Reduce the sharpening layer to 80% opacity to not over sharpen.

Go to filter - other - high pass

Use a high pass setting of 4.0

Go to adjustments - desaturate

Turn the layer blending mode to "overlay."

Create a new layer mask.

Make sure only the Opera House is sharpened by painting out the sky and the water from the layer mask.  When your are done you should only see the Opera house being affected by the sharpening layer.

Reduce the sharpening layer to 80% opacity to not over sharpen.

It is really important when using the "high pass" filter to remove the effect from water and sky.  If you don't, you will add unnecessary noise to these areas.  Always paint them out using a layer mask.

Extra Curves Adjustment: I added an extra curves adjustment to the scene to add a little more contrast to the Opera House.  Using the same layer mask from the "high pass" layer I was able to add just a touch of contrast to just the Opera House. [border]

Adding the Curves Adjustment

Now that we are all done with our fixes it is time to bring this back into Lightroom.

  1. Click file-save As!
  2. Be sure and change your file type to PSD, and click SAVE.  The reason for using PSD is so that you can always go back and make adjustments later.
  3. Once it is done saving, close the file in Photoshop and head back over to Lightroom.

The PSD file should be added to your Lightroom Library.  Almost done! [border]

Save using the .PSD file format.

Save with maximize compatibility.

Step 7: Final Adjustments

Now that everything is finished the last adjustments I usually make are either to the cropping, and if I want to add a vignette to my image.

For this image I'm pretty happy with my crop, but I do want to add a little bit of a vignette to finish it off.

  1. Click on the develop tab.
  2. Go down to the "effects" tab and add a little bit of "post crop-vignetting" to taste.

Adding the vignetting.

Guess what, you are DONE!

Congratulations, you just finished your first HDR Image!

Final Before and After

Emerson Collge Before Emerson Collge After

Want to learn more? Check out my Merge to 32-bit HDR Video Tutorial