Photoshop HDR Plus Photomatix Tone Mapping

| February 1, 2010

When did life get so complicated? The pursuit of visual perfection in photography has never been so achievable so confusing at the same time. Just look at the jargon we have to deal with! JPEG vs RAW, 16-bit vs 32-bit, HDRI, tone mapping, EV bracketing, tone compression, and more. The digital SLR camera and its abundance of settings combined with a plethora of feature rich image manipulation software has created a virtually unlimited number of options for photographers and artists. Out of sheer appreciation for those that take the time to post the methods of their artistic pursuits, I thought I would contribute to the knowledge pool with the results of an experiment I conducted today to increase my proficiency in HDR imaging.

3 EV merge to HDR result in Photoshop

Photoshop has an automated Merge to HDR script built into the FILE>AUTOMATE menu that will allow you to combine multiple exposures of the same scene into a single optimized image. It is generally accepted that you need at least three exposures to create a decent HDR image. Some folks use as many as seven to nine exposures! The image above is the result of running Photoshop’s HDR Merge script on three images I took in Times Square last week. All the exposures were taken in RAW image format at an ISO setting of 100, which was set to minimize noise from the long-ish exposures. When shooting in RAW, the only settings in the camera that really matter are ISO (film speed), shutter speed and aperture. Instead of the camera doing the post processing for things like white balance and image compression, you take control once the image is downloaded into your computer with a RAW conversion program like Photoshop. It is really amazing how much control you have when working with the RAW sensor data. It takes a little practice but once you figure it out, you will never go back to accepting JPEG output again. As you can see, the merged image (number 1) is pretty nice with a good balance between the light and shadow portions of the image. For those interested, I used a 17mm to 40mm professional Canon lens on my 15 megapixel Canon 50D for the shoot. I used aperture priority at f20 to maximize the focus area of the image. Since I was using a tripod, the long exposures did not matter that much.

Although Photoshop has the HDR merging capability, a number of seasoned photographers recommend an additional program called Photomatix Pro by HDRSoft – especially for tone mapping.

Photoshop HDR image tone mapped in Photomatix

You can use Photomatix Pro to do the HDR merge if you like but I have heard that Photoshop is among the best at getting the alignment of the exposures spot on. So, for the purposes of this experiment, I took the file that I merged in Photoshop, converted it from 32-bit file to a 16-bit file (again with Photoshop) and then opened it in Photomatix. I then tone mapped the file to see what I would get. The best way to explain the result is that the lights suddenly went on! Compare the Photohop file (number 1) with the Photomatix tone mapped file (number 2). Look at the “Wicked” sign and how the green and white actually looks illuminated compared to the top photo. Also notice the gladiator dude on the right and how there is so much more rich color in the sign. The building also glows more giving the sense of being lit by the floodlights. Trust me, I tried to get the same effect right in Photoshop by pushing sliders around and it seemed unattainable without blowing out parts of the image. So, the Photomatix step results in a much better image in my view but there are things that I am not happy with that will need to be adjusted again back in Photoshop.

Blended files in Photoshop for desired result

I saved the Photomatix file and then brought both image (1) and (2) back into Photoshop for a little layer blending. The cross of lights between the big signs lost a little something in the Photomatix result (2) and I wanted to tone the far building lights back a little as well as reduce the glow of street level lights since they seemed a little hot and distracting to my eye. To accomplish this, I put the Photomatix layer (2) at the top and the the original Photoshop merged file (1) on the layer below it. I then clicked the Photomatix layer (2) and chose LAYER>LAYERMASK>REVEAL ALL. This creates a mask that I can paint with black to reveal the layer underneath. With my brush set at 30% opacity, I clicked and moved my mouse over the areas that I wanted to show through from underneath. The changes in the composite image are subtle, but if you compare the photo number (3) to number (2), you will see that I have all the vibrance of the Photomatix result (2) with the selectively toned down areas of the original Photoshop merged image (1). I hope this makes sense. If not email me an I would be happy to clarify.

Rich black and white conversion of final image

Incidentally, I tried merging the exposures and tone mapping the files completely with Photomatix. The result was nice but in my opinion, not as good as merging with Photoshop and then tone mapping with Photomatix.

Finally, with all the dynamics of the color image, I wanted to see what it would look like as a black and white photo. As you can see, it makes a pretty nice impression. I love the subtle gradations combined with the high contrast. There is a nice balance with no areas that are distractingly blown out across the dynamic range of the image.

I know all this techo-geek stuff is not for everyone but I wanted to share because I feel that my photographic possibilities were magnified exponentially this week!

Category: Photography, Travel

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  1. HDR à la iPhone? | Wray's Ramblings | February 6, 2010
  1. AutumnLeaves says:

    Again, giving this one to the husband half. I see blablablah, blablablablah…LOL Glaze over on technical stuff as always. But the photo is fabulous, Lee!

  2. AutumnLeaves says:

    P. S. By the way; he is fascinated and really enjoying these last couple of posts, Lee.