How to Create an HDR Image in Photoshop CS4

STEP ONE: Taking the picture

The first step in creating a HDR image happens way before you even open Photoshop. When you take a photograph of an image that has some very dark values, and some very light values, your camera cannot capture the wide range of light and dark. This range is measured in EVs. A normal camera can capture 6-8 EVs of dynamic range. The Photoshop HDR program (and many other third party applications), extend the EV range (of light and dark), so that the dark shadows photograph shows some detail, and the lightest parts of the photograph are not blown out.

So the first step in creating an HDR image occurs when you take the photograph. Because the HDR image will be a collection of two or more images you will need to use a tripod so that the camera won't move when taking the photographs. Some people like to use three shots, and some like to use as many as nine shots, but anywhere between these limits will work.

A: Use Exposure Bracketing ensure that the camera is steady during the entire process.

1. Set the Exposure Compensation Bracket to 0.

2. Set the Exposure Bracketing at 2 EV stops.

3. Hit the shutter release. The camera will take automatically take three shots - the first shot will be at the standard exposure, the next shot at 2 stops darker, and the last shot at 2 stops lighter. If you want more than three shots for your HDR image, you can start with the Exposure Compensation at +2 for the first three shots, (this will give you +0, + 2, and +4 EV), or if you camera will allow it, you can select the number of shots your camera will take in one bracketing group. Of course if you want more range, you can capture the image at smaller EV increments.

Bottom Line:
1. Make sure you have images that include all the darks, and all the lights.
2. Make sure that the camera doesn't move.

B: Shoot in either Aperture Priority or Manual mode. When you shoot a set of bracketed images, the Aperture value will stay the same and the Shutter Speed will change. If you shoot in Shutter Priority mode, then the shutter speed will remain constant and the aperture will change with each shot. This will cause the depth of field to be different in each shot, which could cause the image to be blurry.

C: Use a shutter release cable. Again, you want to reduce all the movement of the camera you can, especially with the lower shutter speed images.

D: Using the mirror lock-up feature in your camera will also help reduce any movement in the camera. When the mirror flipping up when you take a shot can cause slight movement during the exposure (more of a problem with longer focal length lenses). Locking up the mirror will eliminate any movement caused by the mirror flipping up during the exposure.

E: Shoot in RAW, for many reasons, one of which in that it gives the images the widest possible dynamic range. You can still use HDR with jpeg files, but RAW is better.


STEP TWO: Selecting the Images to use.

These are the photos I will be using in this tutorial: As you can see I use more than just three. I bracketed the first three (on the right), then shifted the center mark, and bracketed the next three (on the left).


Image 1

A: Select the images you want to work with.

1. From Photoshop:

a. Open all of the images you want to work with in Photoshop.

b. Click on File > Automate > Merge to HDR


Image 2

c. Select 'Add Open Files'

d. Check the box that says "Attempt to Automatically Align Source Images".

e. Click OK.


Image 3

2. From Photoshop Bridge:

a. Select the images you wish to use.

b. Click on Tools > Photoshop > Merge to HDR.
Note: (You will bypass the Merge to HDR screen shown above.)


Image 4

3. From Photoshop Lightroom:

a. Select the images you wish to use.

b. From the menu bar, Click on Photo >
(or right click on one of the selected images)
Edit In > Merge to HDR in Photoshop
Note: (You will bypass the Merge to HDR screen shown above in #1.)


Image 5


STEP THREE: Set the White Point Preview

The HDR program in Photoshop will merge all of your photos, and the HDR image will look like Image 6. On the left, you can see the bracketed shots you used . The green check mark means that photo is being used. You can un-check any number of the images to see what the composite would look like without using that image. If all of your images were created as I described above, and they were all sharp crisp and clear before you started, then you should use all of the images.

On the right you will notice the Bit Depth, the White Point Preview, and the Response Curve. The only one you will want to adjust will be the White Point Preview. But you will only need to adjust that if your highlights are blown out. In that case you will want to move the slider (under the histogram) to the right until it lines up with the end of the black curve in the graph.


Image 6


STEP FOUR: Save the file as a 32 bit image.

Since you might want to go back to this image at this stage later, it is a good idea to save it as a 32 bit image, even though it is outside the range of what monitors are capable of displaying at this time.


STEP FIVE: Convert to more workable image.

To better work with the image, you will want to convert it to an 8 bit or 16 bit image.
Click on Image > Mode > 16 Bits/Channel...


Image 7


STEP SIX: Open Local Adaptation to adjust Toning Curve and Histogram

1. Click on the down arrow next to method and select Local Adaptation. This will allow you to make adjustments to the tonal curve.

2. From the HDR Conversion box, click on the down arrow next to Tonal Curve and Histogram.


Image 8

This will change the look of the image, and give you a starting point to work from.


Image 9


STEP SEVEN: Make adjustments to Tonal Curve:

 
Image 10

1. To bring out the maximum tonal range, click on the curve point in the top right hand corner of the graph and drag it to the left until it lines up with the right edge of the graph, as shown in image 11.

2. Then click on the curve point in the bottom left hand corner of the graph and drag it to the right until it lines up with left hand corner of the graph.

3. Move the curve up or down to get a curve you are happy with.

4. Adjust the radius and threshold in order to retain the detail and avoid halos in the image. The radius controls the mask blur and the threshold controls what gets blurred. Most often you will want to reduce the Radius a quit a bit.

5. Click OK


Image 11

The goal in this step is to bring out the detail in the image and at the same time leave enough shadow so that it doesn't look washed out and fake. The steeper the curve, the more contrast you will have in your image. Be careful though - you don't want to end up with the same amount of blacks as if you had would have without the HDR process.

This is what the HDR image looks like at this point.


Image 12


STEP EIGHT: Save the file

1. Select File > Save As, or press Ctrl+Shift+S (Command-Shift-S) to open the Save As box, but don't Save just yet.


Image 13

2. As you can see in Image 12, this file still needs more work. For the next step I like to work in Camera RAW. But Camera RAW will only open TIFF, JPEG, and RAW files. If you save the file as a default PSD format, you will not be able to open it in Camera Raw.

3. Click OK and close the image.


STEP NINE: Open the file in Camera RAW

1. Photoshop's File > Open As (MAC: Open)

2. From the dialog box, select the File that you just saved.

3. From the Open As (Format) drop down, select Camera RAW to open the image for Camera RAW processing.


Image 14


Image 15


STEP TEN:

1. These steps will be dependent on what the image looks like at this point. This is what I did with this image:

Exposure: +0.10
Recovery: 55
Fill Light: 14
Blacks: 3
Brightness: +13
Contrast: +9
Clarity: +44
Vibrance: +7
Saturation: 0


Image 16

This is what the file looks like after the Camera RAW adjustments.

2. Some people, perhaps most, would stop here, but I like to do a couple of more things in Photoshop itself, so Click on Open Image.

STEM ELEVEN: Make final adjustments in Photoshop CS4

1. Adjust Level, Curves, Exposure, Vibrance, Hue and Saturation as needed.
2. Adjust the Chromatic Aberration to get rid of any red or blue fringes. Filter > Distort > Lens Correction... I use this tool to adjust the Chromatic Aberration (Fix any Red/Cyan or Blue/Yellow fringes.

3. Use the Lens Correction if necessary to change the vertical or horizontal angle. I used it to make the wires holding the bird sculpture perfectly vertical (which is the only way wires hanging from the ceiling would be positioned).

4. Use Filter > Noise > Reduce Noise (I use the Neat Image Plugin to reduce noise).

5. The final step is to Sharpen the image. I like to use Filter > Sharpen > Smart Sharpen

This is what the final image looks like:


Image 17 - Click on image to see larger view.

Check back to find tutorials on these steps, taken in Photoshop, in more detail.