How To Guide on Essential HDR from Imaging Luminary

During it's beta period was known as “Project Wukong”, now it's being called as Essential HDR and the first version has been released a few weeks ago by Imaging Luminary. For the rest of this document, I'm going to simply call it by EHDR.

This new software aims at producing more natural and realistic results than any other HDR software with it's “Detail Revealer” technology which is the local tone mapping operator that simulates the Human Visual System. According to Imaging Luminary's website, this is a new algorithm that compared to other local tone mapping algorithms, will produce high detailed images with less artifacts known as halos, haze and random brightness variations.

A community version is available for download which is basically a demo version featuring everything available in the standard package but with small limitations such as the output images having a 1 megapixel size restriction and a small waterkmark in the bottom.

In case you don't know what HDR means and you haven't clicked the Wikipedia link, HDR translates into High Dynamic Range.

What does that mean exactly?

Have you ever wanted to shoot indoors but the outside world through the window was overexposed? Or shoot a landscape with a clouded sky against the sun but you can't manage to correctly expose both the sky and the landscape? HDR is here to help you fix that and at the same time reveal more detail in your image allowing you to create some unique photos. By shooting multiple pictures with different exposure levels and combining their dynamic range using software like EHDR you can achieve very natural looking photos or you ca go a little bit further and give them a unique and surreal look.

There are two main methods for creating the source images for your HDR. Shoot one single RAW file and use your RAW editor back at your computer to create 3 shots with different exposure levels, or shoot multiple RAW files using AEB, auto exposure bracketing. Let's start with the former…

If your subject is people moving, birds flying or wind blowing leafs on a tree, this is probably the best method. It may not work very good on some extreme situations though. The idea is to load your 0EV RAW image in your RAW editor, set the exposure level to -2EV and save the image as 16bit TIFF, reset the exposure to 0EV and save it, set the exposure one last time to +2EV and save it again. The downsides of this method is that it doesn't allow as much dynamic range as multiple RAW files and noise will also become a problem if your image has very dark shadows.

The other method and more preferred is AEB and it's a feature that most digital cameras in the SLR market have that allows you to easily and quickly take multiple pictures with different exposure levels. This method allows a far greater dynamic range because you take separate pictures for the shadows and highlights, maintaining all the detail. Noise won't be much of a problem for the most part. You will need a camera that supports AEB and since the multiple pictures are not taken at the same time, you'll also need a tripod so they get perfectly aligned. This is different from camera to camera but you basically need to set the AEB mode to shoot on -2EV/0EV/+2EV. Normally this will produce good results but you can also try -1EV/0EV/+1EV or even go for a 5 image set with -2EV/-1EV/0EV/+1EV/+2EV or more. This will probably give you a more balanced picture and you can always choose which images to use later on. The only downside of this method is that you'll probably get ghosts of people or anything else that moves between the shots taken.

If you want to create good looking HDRs capturing the biggest dynamic range possible and keep the noise to a minimum, you must never shoot in JPEG. Although some scenes may work fine shooting in JPEG, it's always recommended to shoot in RAW to save all the data captured from the camera sensor and sometimes, “fine” may not be good enough.

The JPEG file format only has 8-bits per channel which can roughly display 16,777,216 colors. But if you shoot in RAW you will have 12-bits per channel¹⁾ leaving at your disposal 68,719,476,736 colors. You can see this is a big difference turning RAW shooting essential to any photographer and it's even more important for HDR photography.

If space is no problem, always shoot in RAW!

If your camera has AEB but you don't have a tripod you may still have a chance at HDR if you don't shake a lot or if you can support your camera in a wall, bench or whatever. If your camera doesn't support AEB, you'll indeed have to support the camera somewhere and manually take the pictures necessary while changing the exposure of the scene in between shots.

Don't worry if the pictures are misaligned, EHDR will take care of that for you. Don't expect it to make miracles though cause it's a feature that still needs a bit of more tweaking. Always try to support the camera somewhere (always use a tripod whenever possible) to minimize the risk of misaligned pictures.

But for those hand-held shots that you couldn't do anything about or EHDR failed to properly align, I recommend you to try the following tool:

HDR Alignment Tool v2.0

For this tutorial I'm going to use a 5 picture set that I shot of my living room. You will easily see that it would be impossible to capture the full dynamic range on this scene in one single shot, even if it was shot in RAW.

The 5 picture set with different exposure levels are the following:

1/1250 sec	1/320 sec	1/80 sec	1/20 sec	1/5 sec

Looking at the pictures is probably making you think that only 3 of them would be more than enough to create an HDR of this scene but I assure you that the final result will be much better using all of them. Like I said before, my advice is to shoot 5 or even 7 with 1EV steps if card space is no concern to you. It's always best to shoot a larger picture set than to shoot a smaller set and then realize the exposure levels difference is not enough or produces unexpected results. You can always pick the ones that work better for the respective scene later on.

Most of the time you'll realize a 3 or 5 picture set is more than enough. It really depends on the scene and how much dynamic range you want to get out of it. For this living room scene, these 5 work better.

The next step is to open all the files in the set inside EHDR and merge them but here's where you have to make the choice to align them or not.

As far as I've tested EHDR, the alignment feature still needs more tweaking. My tests showed that you really have to test the alignment for yourself and decide what works best for you. The time it takes to do the alignment process is only a couple more seconds so you don't have much to loose really.

General rules are as follows:

• If you've used a tripod and there's no movement between shots, spare yourself a few seconds and don't align the pictures.
• If you've used a tripod but there are some movement between shots, try with alignment and without and see which one works best.
• If you've shot hand held and unless you have a really steady hand, definitely use the alignment feature.

Now that you've decided to align or not the pictures before merging them it's time to open the files.

Go the File menu and choose Align And Merge Multiple Photos to select a set of images and merge them into one aligning them before the merge. Or choose Merge Multiple Photos w/o Align to select and merge a set of images without aligning them first. For the example in this tutorial I opted for align and merge.

After selecting the picture set, the pictures are going to be aligned (if that's the case) and merged into one. By default, the Fast Tone Balancer will be automatically run with all the default parameters after the merging process.

If the results are satisfactory, just leave it be, if not, press the Tone Mapping button and let's tweak the tone mapper values a bit. For the tutorial example I switched over to the Detail Revealer tone mapper. This is the one that you'll be mostly using as it produces better results and much more detailed images.

For this particular picture, I'm going to set 30 for Details, -2 for Brightness, 100 for Color Saturation and 10 for Fill Light. This values won't work as good if you use the JPEG images available in this tutorial because they only have 8-bits per channel and I'm using the TIFF images converted from the RAW files which have more than 8-bits per channel. Still, if you want to test EHDR with the images on this tutorial, use the following values instead: 40, -7, 65 and 0. Note that these values are merely an example, they depend on the scene, your eyes and on what you want to achieve.

To save the final result press the Save Result As… button, select the image name, type and location from the dialog window and save it. Some times, the final image should benefit from a little more post-processing on an external photo editor like Photoshop or Lightroom as EHDR still doesn't offer many controls to tweak your final image. That's really up to you.

The results below show the final images produced:

Final Output From Essential HDR	Final Output From Adobe Lightroom

The Tone Mapping toolbar provides a simple way to preview and compare different parameters for the selected tone mapping algorithms or just display a single preview for the selected tone mapping algorithm. You can compare different parameters between the same algorithm or between the different ones.

The toolbar also allows you to save the current tone mapper parameters or load previous saved ones in case you are still not finished with the tone mapping on some specific picture.

The Tone Mapper algorithms are the ones responsible for transforming your HDR pictures into “normal” pictures that can be correctly displayed on our computer screens. EHDR provides two different algorithms, Fast Tone Balancer and Detail Revealer.

The Fast Tone Balancer algorithm optimizes the tonal range of an HDR picture which is normally done by the “curves” feature on traditional photo editing software. It compresses the overall contrast in a very effective way and gives you a quick preview of the final result, mapping the HDR picture to an 8-bit RGB output.

On the other hand, the Detail Revealer algorithm is based on how the human eyes respond to real world high dynamic range scenes. It has many advantages against other algorithms like much more detailed images with less artifacts known as halos, haze and random brightness variations. It's also very fast, providing an incredibly accurate preview of the final picture.

EHDR is different from other HDR software packages in many ways, one of them is aless confusing interface with lots of parameters to configure. Some people may not like it this way and will need more control; making use of an external photo editor over the final result produced by EHDR. But it's a very simple interface and most of the times will get the job done with excellent results.

Most of the Tone Mapping parameters in both tone mapper algorithms are not different from the traditional photo editing software and I'm not going to explain them. The Histogram and Color Balance are also common controls found in every photo editing software and I'm not going to explain those either. If you don't know what are they for and how to use them, you are reading the wrong article.

The only important parameter that I'm going to talk about is the Details slider in the Detail Revealer tone mapper. This parameter controls how much detail you want to reveal on your picture. Pushing the slider to the right will reveal more detail, pushing it to to left will reveal less.

It all depends on what you want to achieve with your picture. Push the slider too much to the left and your picture will get a more soft look, pushing it too much to the right will make your picture more surreal. If you want to keep a natural and still detailed picture, find the point that suits you best between 30 and 70. Less or more than that will start producing a less realistic picture.

All the pictures are copyrighted by their respective owners and I take no credits for any of them. Even though some of the final HDR pictures were created by myself instead of their original authors²⁾, they were kind enough to provide me with some samples. Full credits for the original photography goes to them.

Every single one of the HDR pictures below were created with Essential HDR Standard Edition v1.0.

Writing in English can sometimes be hard for me, specially when I'm writing an article like this; and I also didn't learn everything I know about HDR all by myself.

Because of all that, I want to thank and give some credit to the following people:

• Peter Carr from Vanilla Days
  HDR Tutorial: How to create ‘High Dynamic Range’ images using Photomatix
• Royce Howland from NatureScapes
  The High Dynamic Range (HDR) Landscape Photography Tutorial
• Ryan McGinnis from Backing Windows
  How to Create Professional HDR Images with Photoshop