Comparison of HDR Techniques
HDR Photography is a method of combining multiple exposures into a single image in order to achieve a greater dynamic range in an image. If that sounded a bit complex, let’s break that down a bit more. If I take a photo, the sensor only can capture a given range from light to dark, in a normally exposed image, you may lose some detail in the darkest areas and you may lose some detail in the brightest areas. But if we can take an normal exposure, an underexposed image (to get the detail in the highlights) and an overexposed image (to get the details in the shadows) and combine them into a single image, then we can get a new image that can be the best of all three. In this article we compare three common ways of combining these images.
While there are a number of other programs available to do HDR with, we are going to look at the three most common ones mentioned in most posts and blogs, these are:
- Adobe Photoshop CS4 – Merge to HDR Function
To be completely fair, I am using the different HDR tools here with their default settings and am not doing any additional tweaking afterwards to make the images look better. That being said, the Photoshop result is certainly the worst of the batch. The dark areas are too dark, the bright areas are too bright and it just didn’t do anything to really impress me. I also cannot find any noticeable difference between Photoshop CS3 and Photoshop CS4 in the final output. Even though you could tweak this image in Photoshop, it would be quit a bit of work because you really need to darken the sky and brighten up the building and parking lot. There may be a particular type of image that Photoshop likes better, of perhaps it doesn’t like that the images covered a 4 stop range. If someone has some tips on working with the Photoshop HDR merge, please post them in the comments.
Photomatix is another commercial tool (http://www.hdrsoft.com) that many people consider to be the best HDR tool available. Comparing the images, the Photomatix output most certainly gave the most dynamic range, so much range that it is actually easy to get an image that doesn’t actually look natural. The way Photomatix works is a complete mystery as even in the overexposed image, you can’t see the detail in the windows and doorways of the building the way you can in this Photomatix output. From a “wow” perspective, it is most certainly the most vivid image and has an amazing amount of range, there is almost nothing in the image that is too bright or too dark. While this may be good for some images, if you are trying to replicate what you are seeing with your eye, this isn’t quite accurate. Is it stunning in it’s range? Absolutely, no question there, it wins hands down in that area.
Enfuse is a different type of tool that compares multiple images and chooses to keep the pixels it feels are the best exposed. Using Enfuse by itself can also be an exercise in frustration. To simply using Enfuse, I use LR/Enfuse from Timothy Armes (http://timothyarmes.com/lrenfuse.php) which integrates into Adobe Photoshop Lightroom. Using just the default settings, the result is an image that is much more natural and is truer to what you would see with your eye. A big advantage of using Enfuse (especially with LR/Enfuse) is that it is significantly faster than Photomatix, the downside is that you don’t get the amazing results that you can get from Photomatix. Enfuse is going to give you a far more natural look.
It’s not entirely clear if these is a real no-brainer choice between Photomatix and Enfuse as it is really dependant on what you are trying to accomplish with the final image. Photomatix can certainly deliver outstanding images that are virtually impossible to achieve any other way and can also create more natural looking results by toning down the resulting image making it a more versatile tool overall. Enfuse has its advantage in being fast and easy to use when integrated into Lightroom and will create very nice, natural looking results, and if that is your goal then sending a few bucks to Timothy for LR/Enfuse is well worth it. Personally, I have both installed and will choose when to use each tool based on what result I am looking for, and knowing the strengths and weaknesses of each option will make it easier for me to decide when to use which tool.
Author: Kerry Garrison