enthusiastic about enfuse

I've dabbled with HDR photography a bit in the past, but always felt the results were quite cartoonish. The saturation is often off the charts and the local contrast added by most tone mapping algorithms typically seems very heavy handed, for what I want to achieve. While that is a perfectly valid thing to do, it just doesn't appeal to me that much. I have managed to do some more realistic HDR images, using the Wukong beta/ Essential HDR product from Imaging Luminary but since I moved to a Mac, I haven't been able to use their software. I started looking for something similar for OS X and got a recommendation for Enfuse. This is an open-source solution to the problem, that takes quite a different approach to blending the exposures.

Instead of generating a merged, high dynamic range image with floating point pixel values, the enfuse algorithm picks out from across the various exposures what it considers to be the best exposed pixels for a particular region, then merges them all together. There is some level of control for the user; to provide masks, or bias it towards keeping contrast or saturation in the image. The algorithm can also automatically align images, if you haven't shot them all on a tripod. I've found that the defaults work well to merge a well exposed set of images. The resulting merged image is then a great starting point for further adjustments.

While Enfuse is open source and available for free, I've been using an Adobe Lightroom plugin that is sold as donationware, by Timothy Armes. The LR/Enfuse plugin simplifies running the merge from Lightroom. I just have to select the various exposures and run the plugin to get a merged result back in Lightroom, ready for further adjustment.

Many years ago I learned to shoot pretty wide brackets around a given exposure when I'm working on a tripod. With digital, the brackets are essentially free and this ensures you have all the data you might need to merge exposures back at home. Particularly when working with fleeting light or in hard to get to locations, I'd rather shoot a few more frames at the time, than wish I had them when I got home. I'll typically pick a working f-stop, based on the depth of field I want in the scene, then shoot at one stop intervals around the metered exposure, from -2EV, -1EV, 0, +1EV and +2EV. I normally do this in Aperture Priority mode, so that only the shutter speed is changing, but the depth of field is constant. In some cases, if there are particularly extreme lighting situations, I might shoot another stop above or below those as well, but I've found that five stop increment is often more than I need, particularly shooting around twilight. These 5 exposures give me a great starting point to blend for a final image. In the past I might have processed them as multiple exposures and then layered them in Photoshop, using masks to pick out particular parts of the image. Now they are a great starting point for Enfuse. In the example above, the porch of the building was in really heavy shadow, in the noon day sun, so I've shot 6 exposures, to get some detail and deep colour in the shadow areas (in the lightest exposure, to the far right), while still trying to keep some detail in the white, reflective roof (in the leftmost exposure).

To run the merge, I pick the darkest exposure that still had the right levels for the lightest parts of the image and the same at the other end, selecting the lightest exposure that had the shadow values that I wanted. I then use those as the outliers and pick all the in-between exposures and run the Enfuse plugin. I haven't tried varying the default values yet, as it has given consistently good results from the images I took in Big Bend. Enfuse is a great option if you are interested in working with scenes with a large range of tonalities or extremes of lighting, but want to try to produce more natural results. The price is right too. There are other GUIs available for Enfuse, if you don't like using Lightroom. I haven't had any experience with these, but options such as EnfuseGUI do exist if you wanted to avoid Lightroom and also the command line.

the aftermath

So back home and now trying to manage the rest of the SoFoBoMo process. Haven't really even started looking at the images, never mind editing any of them. Just shuffling around the 20Gb, 2000+ image files, renaming them, backing them up, getting previews set up and that sort of thing, ready to start looking at what I took. I've picked out a few that have caught my eye and done a quick edit, like this one above and the previous two posts. I've got no idea if they will make the cut for the final book. I don't even know what the final book is going to be about - probably just bundled under the theme of 'road trip'. I'm sure Colin Pantall has a 'how not to photograph' that addresses that sort of random collecting head on, but it is what I have.

Process while traveling was pretty straight forward. Shoot things that interested me. Drive Amanda crazy. Repeat. Then in the few evenings when we had power, dump the contents of the CF cards to my very small and underpowered linux laptop drive and also to a removable backup drive. These were then stored separate from each other, so that if someone stole my camera bag, or broke into the car, or stole the car, I'd at least have the backups and a story for the insurance company. I did no editing and almost no review all last week. No time, too small a screen, limited power for the camera to even chimp much, particularly when trying to do night shots (long exposure equals quick battery drain). The fun part of that is that a week later I'm now actually hopefully going to start getting to see the images. (when this backup actually finishes) The bad I suppose is that I could well have screwed up many days of things without realising it and it would be about 500 miles for a retake.

The other thing I'm finally getting to grips with, spurred on by SoFoBoMo is calibrating this new Mac and getting things like Adobe Photoshop actually configured again. All things I should have done a few weeks ago when I got the computer, but laziness always finds a way. I shot quite a few images with the thought or potential to make HDR versions of the results, even though I've never tried it with the Mac OS X HDR software options (which I don't currently know much about - any reviews, raves, suggestions there? comments very welcome).

This evening then is mostly book-keeping, fiddling, renaming, filing, sorting and getting ready to start getting ready. All busy work really but essential I suppose, if I'm going to get this random assortment of stuff into some sort of book shape. Should be fun.

The image above was taken in Big Bend National Park, in the Chisos Mountains basin. There was a fair bit of pre-planning involved - picking the right camp site, with the right view of Casa Grande, on the right day that the moon was going to rise over it, as a full moon. The tent was partially pitched with this shot in mind (and mostly pitched with how the ground sloped in mind, too) There was a large helping of luck involved too, I didn't expect the moon to rise quite so perfectly over the corner of the big mountain. That actually was painful because it meant the moon shadow was all around us for a good hour before the light really actually touched our campsite - quite frustrating if you wanted to get some sleep!

For lighting, I put a Canon 580EX II speedlite in the tent, with a full CTO gel over the flash. The tent was already orange and red, but I wanted to use the CTO gel so that I could shoot in Tungsten white balance, to really get the deep, midnight blue into the clear night sky. The CTO gel and Tungsten white balance cancel out for the tent lighting, returning it to the already red/ orange appearance. I used a Canon ST-E2 remote trigger to control the flash in TTL mode and then just waited for the moon to rise and worked out a reasonable exposure, stopped down quite far to give enough depth of field to get the mountain silhouette sharp and the tent in focus. The stopped down aperture also causes the bright moon to create the ray/ star effect.

high dynamic range - it's not just for Saturday mornings

3 image hdr

I've never really gotten the taste for the typical High Dynamic Range images. Trey does a great job in that style, but it just doesn't connect with me. So I've tended to avoid HDR tools. Occasionally, however, I get presented with a scene which is beyond the dynamic range my camera can handle. Usually I'll bracket the exposure then mix the images later with masks. Recently I signed up for a beta program of a new HDR tool. Most of the default results from the tool have the typical extremely high local contrast look that seems so popular to add in the tone mapping stages. But it can be dialed back and controlled to give a less obvious effect. I found I was able to blend several exposures without too much trouble, to get something much closer to what my eye could see, but without the overloaded local contrast in the image.

2 image hdr

I'm no expert at HDR (I think I've been happy with three final images in total) but it can be a useful tool to have in the back pocket, particularly when it can be used without being such an obvious part of the final result.