Exposure Fusion: What is it? How does it Compare to HDR? How Do I Do It?

Exposure Fusion: What is it? How does it Compare to HDR? How Do I Do It?


Today Mark Evans from Smash and Peas Photography Blog shares an explanation and starting points with Exposure Fusion.


Image by Seb Przd

‘Less is more’, or so the saying goes. But in this case, I guess its true; less effort and less time equals more productivity and and better results, what more could one ask for? So from where I’m standing, Exposure Fusion looks to have everything going for it, and then some.

What is Exposure Fusion?

Lets set things straight from the start, Exposure Fusion is not a kind of HDR.

Exposure Fusion is a fairly new concept that is the process of creating a low dynamic range (LDR) image from a series of bracketed exposures.

In short, EF takes the best bits from each image in the sequence and seamlessly combines them to create a final ‘Fused’ image. Or more technically, the fusing process assigns weights to the pixels of each image in the sequence according to luminosity, saturation and contrast, then depending on these weights includes or excludes them from the final image. And because Exposure Fusion relies on these qualities, no exif data is required, and indeed, if you wanted to, you could include an image with flash to bring darker areas to life.

Exposure Fusion Advantages over HDR

Using this process actually has a few advantages over HDR.

For one, no intermediate HDR image needs to be created, and therefore no tone mapping step is required either, making Exposure Fusion a far more efficient and quicker process. Not only that, but due to the algorithm used in Exposure Fusion, halos around objects that would otherwise ruin a nice HDR image have been completely eliminated, resulting in a more natural looking final image.

Exposure Fusion also has one other trick up its virtual sleeve. It can also create extended Depth Of Field images by fusing together a sequence of images with different DOFs. This could actually be quite handy, say if lighting conditions at the time don’t allow the full DOF to be captured in one shot, or if you’re just limited by the DOF of your lens. This process could also be used creatively to get different DOFs in one image.

Here are some examples of both methods – click to enlarge.

enfused.png hdr.png

Exposure Fusion Software

At this stage Exposure Fusion is still in its infancy, so there’s only a handful of programs to choose from.

Enfuse is the primary tool for Exposure Fusion at the moment, and although it is a command line utility, there are ‘‘droplets’‘ (batch files) available that you can drag and drop a series of images onto to create a fused image.

Ingemar Bergmark has produced a GUI for it, not surprisingly called EnfuseGui, which can be a little easier if you aren’t too keen on command lines. If you’ve got Lightroom then one of the more convenient ways is to use the plugin. It still uses the command line utility in the background (you have to tell it where your enfuse.exe is), but the process looks more refined. However, the plugin is donation-ware so its limited to 500px final images until you donate to get the full version. There is currently no plugin for Photoshop. If you’re into photo stitching then PTgui and Hugin may be of interest to you. These programs utilise Exposure Fusion by stitching and fusing bracketed sequences together, with some pretty nice results.

Die-hard HDR fans may not be too impressed by this new revelation, but I certainly am. With no tweaking at all, a pretty reasonable final image is spat out of Enfuse. I must admit though, to get the images looking their best, a little ‘fill light’ in Lightroom helps, and adding contrast and saturation layers also helps bring out the best in the Fused images I created. I’d have to say though, it was a lot less arduous than endlessly changing settings in Photomatix to get things looking right, and I like the end result better, but I suppose on the flip side, this means less control and less creative input from the user, and on the odd occasion, you just can’t beat a nice HDR. Tough choice. I’ll let you decide.

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Some Older Comments

  • Seacoast Shots November 6, 2012 06:52 am

    Awesome information, thank you! My pictures are starting to look a lot better using this technique rather than processing everything in Photomatix!

  • IN April 4, 2012 10:18 am

    Haven't heard of the term exposure fusion before. Really need to updates myself :D But I really would like to try this one. Thanks for the infos.

  • Yvan Van Hoorickx February 14, 2012 04:28 pm

    Great artticle. And I'm using LR/enfuse for all my interior photography. Because time is always a matter for me during shoots, I can't using strobes. Exposure fusion was the best solution.

    Here a list of shots I do, for a City guide magazine: http://www.360vt.be/cityzine
    Real estate shootings: http://www.virtuelewoning.be
    And the ice sculpture in Bruges: http://www.360vt.be/vt_icesculpture2011

    all done with LR/enfuse.

  • PASCAL Philippe February 6, 2012 09:29 am

    I use SNS-HDR because it brings the most natural HDR result i can get.
    HDR Efex is very nice too, with the U-points feature.

    But i'm looking more and more toward "exposure fusion" to get a natural result.
    I'm really bored by HDR over-everything looking photos...and i realize most softwares just push the user in this direction.

    This is like the stupid dubstep wobble bass on every single you hear : boring

  • Dale Mead August 25, 2011 04:42 am

    Great article as far as it goes; you have convinced me I *don't know* what so-called HDR is, as distinct from exposure fusion. (Photomatix 4 gives us a choice, BTW.)

    Please tell the other half of the story. Specifically, why is a 32-bit composite image necessary/advantageous for "HDR"? How is it employed in the processing? And how does the program get 32 bits (billions more) of information from 16-bit (actually 12- or 14-bit in the camera) pixels, anyway?

    If you do write a new article on the second half of this comparison, please announce it in these comments so I receive an email and can read it. I got this URL from a friend after we had a lively discussion about it.

  • karcoos April 27, 2011 12:38 pm

    Another choice for photo stitching is http://www.acropano.com

  • Trevor Sowers April 10, 2011 03:42 am

    I am not a fan of HDR but I'm loving Enfuse! I'm using bracketeer which is a nice GUI for Enfuse and it's available on the Mac App Store.

  • Calvin September 22, 2010 05:24 pm

    Just wondering if you made any white balance adjustments on the enfused image. Unlike the HDR image, it is balanced for both the indoor lighting and the window.

  • Matt Kadlick August 19, 2010 07:54 am

    An LDR image is just a single exposure is it not? The whole point of blending several exposures is to get a higher dynamic range than what you get with a single shot. The idea of a faster automated cookie cutter approach to producing HDR's misses the point completely. The draw of a true HDR, as I see it, is that it is a form of art that takes several steps and some creativity to do it right. Those who have halos in their HDR's haven't bothered to finish them by blending in some of the original raws, and those that over do the HDR effect to the point of flattening or cartooning the image just give HDR's a bad name. I think this process looks very interesting but to say this isn't a form of HDR I think is wrong, it sounds like the continuing evolution of the art form to me. Just my 2 cents

  • TJ March 2, 2010 02:38 pm

    I use HDR techniques mainly to be able to control the lighting conditions in the workflow later on (since I have a bad skill with controlling EV in the scene itself). Anyway, I've been experimenting for some time with EF (by Photomatix) and yes, it does produce some nice images and smooth colors as well. One thing I was experimenting with is, mixing images with different WBs. It gives (sometimes) a nice hue of colors.



    Now, I read in the post about the DOF, so I think I shall try this as well soon.
    Great article! Thanks!

  • Gene Rimmer February 26, 2010 05:24 pm

    Sounds like a good idea but you've got to get away from the command line and simple gui. Seamless plug-in for Photoshop & Elements will go a long way in creating acceptance. I'm an artist and hate to fool with the technical stuff. Make it user-friendly but competent.

  • michael February 25, 2010 02:28 pm

    I'm sorry, but exposure fusion is by definition a HDR image. Read the words: high dynamic range.

    The distinction that you're making is between tone mapping and exposure blending. The result is a LDR image processed from multiple exposures. The intermediate file is a HDR file, regardless of how you process it.

    Saying that the process difference makes a difference is like saying that a hole dug with a specialty spade is different than one dug with an ordinary shovel. A hole is a hole. An image fused or blended from several images of different exposure settings is HDR.

  • Russ January 16, 2010 07:35 pm

    Of course, you could always just used the latest version of Photomatix which includes Exposure Fusion.


  • Sebastian Nibisz October 23, 2009 11:25 pm

    I recommend the SNS-HDR. This tool is better than Enfuse.

  • johnp July 30, 2009 12:25 pm

    Paul the Pentax K7 can develop in camera HDR using 3 bracketed shots. Still need a tripod though.

  • paul pacurar July 29, 2009 11:39 pm

    a treasure for any photographer; extreme color / tonality range situations are very very usual. My concern is about how these tools can properly blend several HAND HELD shots (slightly moved or/and rotated). I will test. So, until the invention - if will that be - of a new HDR camera sensor*, these tools are of great help for us!
    *at least a sensor which prevent highlights and color clipping

  • johnp March 18, 2009 10:44 am

    I have found the (free) average exposure blending in Photomatix an excellent substitute for dodging and burning light/dark areas in a single photo or other methods of correcting exposure in parts of an image. I save two or more duplicates of an image using levels to lighten or darken each one and then open them all in Photomatix. I feel it blends the images to produce an image much better than can be achieved otherwise and is simple to use. It helps though if the original image has no blown highlights or shadows.
    I have had less success with blending my bracketed images however unless a tripod is used and there is no movement at all within the bracketed images. Any movement will result in some blurring in the image. Rather than export bracketed images to Photomatix I do still bracket them in camera but only select the best exposed image to work on and delete the rest. It saves space on the camera card as well.

  • photo restoration retouching March 17, 2009 09:15 pm

    hdr techniques in my opinoin are overused and also usually overmanipulated. This method seems to be a more realistic approach

  • Lucian March 16, 2009 05:26 pm

    I believe the term HDR lost its original meaning, as it was used in the name of the tools meant to extend the tonal range. It doesn't matter how you extend the range, manually (ie: photoshop), blending the bits together, or using a tool (sorry for yet another confirmation). I used to do it myself before knowing what HDR is, just playing with photoshop; then I heard of HDR and I started to put notes on my photos 'hdr-ed', and use various (free) tools, but never got the result I liked ... so went back to photoshop.

    I like this article because it clarifies things, bringing a new (for me) terminology: exposure fusion. Not linked with a tool, but rather describing a process. In comparison, HDR defines the expected result, higher range. So different perspectives only.

    on RAW: people tend to use a tripod and bracketing; but actually, unless if too much noise in the photo, from same raw save with different exposures one can obtain the same results as with bracketing ...

    2 examples:

    http://www.flickr.com/photos/mlucian/3300511324/ with bracketing

    http://www.flickr.com/photos/mlucian/3276512366/ from same raw file ...



  • Studiophototrope March 16, 2009 12:00 am

    I believe that much of the perceived "problem" with HDR images is the lack of understanding that the final result is the choice of the photographer. Once HDR software creates the original radiance file from the bracketed series, the Tone Mapping process leaves the "look" of the final output entirely in the photographer's hands. The resulting hyper realistic image, or over baked image, or something in between is not a product of the software and thus, not a product of bracketing exposures to obtain a wide latitude of exposures. It's the product of the *decisions* made by the post processor.
    Painting HDR's with a broad, negative stroke, does a disservice to the concept and process of high dynamic range.
    What Photomatix and other HDR software does, can and has been done manually in Photoshop [as pointed out by mrt in his response] without ever using HDR software. Now, the creative process starts when one uses HDR software in conjunction with Photoshop masking/post processing to create the desired result.
    I believe the HDR "debate" is what has become the problem.

    "Lets set things straight from the start, Exposure Fusion is not a kind of HDR.....In short, EF takes the best bits from each image in the sequence and seamlessly combines them to create a final ‘Fused’ image."

    If you really want to "set things straight", you just defined HDR.... Exposure Fusion **is** high dynamic range imaging, as Guille says, "It's a no brainer".
    Best regards,

  • ziad chatila March 13, 2009 01:16 am

    Interesting technique. Does not seem to accept RAW images though.

  • Heather Rankin March 13, 2009 01:15 am

    Jumping in .... I live in the Lake Powell area of Southern Utah and Northern Arizona with astounding views in every direction. While I am still rather 'new' to all of this, HDR photos work lovely here. It's taken some time to figure out that 'less is more' in so many of them. I'm a real estate agent and my clients are very happy with the photos we end up with.

    Halo's are the biggest problem I've run into shooting an indoor scene with HDR's. I've taken to shooting at mid-day with natural lighting (if possible) and have had wonderful results.

    Thank you so much for the explanation here. I use Photomatrix and am excited to try exposure blending. I am photographing giraffes today at a local preserve so this is a great chance to try both formats.


  • Fredshome March 13, 2009 01:03 am

    I don't know but this mostly seems to me to just be "HDR done right" and then toned down to a displayable dynamic range.

    I can easily compute an image from a series of shots with a range spread over 32 bits per colour which cannot be displayed but which will definitely be "HDR" (although a fairly unusable one).
    Or for a more typical example, HDR has been thoroughly misused when its purpose was originally just to get the correctly exposed bit from a series of shots and then blending the whole series together to get something that actually worked as a single image.
    Then people found that by playing with tone mapping they could get amusing results (which are amusing for, roughly the first five shots) and now HDR suddenly became synonymous with ugly overdone crap.

    So after all maybe at this point a new name is needed. Let's get rid of HDR and use exposure fusion.

  • Brent Brown March 11, 2009 03:10 pm

    Not mentioned in your excellent report is Mac-based Bracketeer -- a great front end for Exposure Fusion.

  • (CMC) March 10, 2009 07:32 am

    I have used my in-camera photo editing (Nikon D80) to overlay under and over exposed images to get this effect. It's pretty neat and dead simple to use.

  • Kerry Garrison March 10, 2009 03:56 am

    For those who think that HDR images do not look realistic, they have never seen good HDR before then. HDR CAN be used with smoothing to create almost cartoon looking images but it can also be used to create very realistic images that are not possible by other means.

    The following is an article comparing different "HDR" effects including enfusion:


  • Jon Tabar March 10, 2009 03:14 am

    Very interesting. I wonder how my HDR panorama pic of Trinity Cathedral in Cleveland would look using Exposure Fusion. I've had problems with halos when I use HDR.

    P.S. - if you guys like my Trinity Cathedral pic, please consider voting for my dream photo assignment to go to Europe and shoot HDR (or Exposure Fusion?) panoramas of cathedral interiors!

  • Jeffrey Kontur March 10, 2009 02:46 am

    I wouldn't say this is LDR at all. The final product definitely captures and display a higher dynamic range than is native to the camera taking the original images. So it's really just a different way of doing HDR. That said, I think the technique holds a lot of promise and the examples presented here speak for themselves. This is certainly something I would try.

  • Yuni March 9, 2009 10:37 pm

    This is very interesting but I'm so wet behind the ears that this was absolute jargon to me. :( Maybe some time in the near future I'll understand this.

  • Guille March 9, 2009 10:11 pm

    Yeap, Chas is right, those names are BS. A High Dynamic Range image is one it has a (take a guess) high dynamic range!!! The rest is commercial trash talking-naming.
    Your camera sensor has a limited working dynamic range and taking bracketed exposures and blending them using different techniques leads to a "High Dynamic Range" image. No brainer.

  • Chas March 9, 2009 09:56 pm

    Photomatix claims to do both: "Photomatix offers two ways to solve this problem: HDR Tone Mapping: Reveal highlight and shadow details in an HDR image created from multiple exposures. Exposure Fusion: Merge differently exposed photographs into one image with increased dynamic range."
    Personally, it seems silly that every time we come out with new HDR algorithms and ways of merging multiple images well think of a new name? Next up... Image Fission, Image Melding, Image Synthesis??

  • ArazPhoto March 9, 2009 09:55 pm

    The Lightroom Plugin is by Timothy Armes called LR/Enfuse.
    He accepts donations of any value to give you the unlock code.
    And his stuff just works.


  • Stephane March 9, 2009 09:55 pm

    Exposure Fusion is also available from Photomatix: The "Exposure Blending" methods are all types of exposure Fusion. Exposure Blending - Adjust is actually the same algorithms as Enfuse - The photomatix team actually helped on testing Enfuse.

  • Jon March 9, 2009 08:54 pm

    I think using the term LDR is a bit misleading, this just looks to me like an automated way of doing manual exposure blending, or focus stacking.

    Could come in handy though, especially as it does both.

  • Joey Rico March 9, 2009 08:52 pm

    problem with HDR is that it looks like a painting!!! as i've seen here this has better colors!!!

  • David Ford March 9, 2009 02:59 pm

    I stitch quite a few panoramas using Autopano Pro. An effect very similar to this (won't claim it is the same technically) can be obtained by letting Autopano pro blend three exposure bracketed images using "smartblend". As mentioned in the article, the results often need a bit of contrast enhancement, but the details are all there from underexposed highlights to overexposed shadows. Perhaps, if you already have Autopano Pro, you won't need another tool?

  • twig March 9, 2009 12:36 pm

    This sounds like a technique that is certainly worth a try. Im not impressed with HDR looking like a painting.
    So I agree about HDR photos looking poor because their way overdone.

  • MRT March 9, 2009 10:27 am

    New? I've been doing this manually with photoshop masks for years! It's fairly simple... Of course, its not automated, but it does give total control...

  • Jeremy March 9, 2009 10:21 am

    This sounds interesting but I hope that it produces slightly more realistic images than HDR. I've seen great, real looking HDR images but the vast majority of them are too strikingly large a dynamic range to really be taken as more than gimmicky.

  • CVR March 9, 2009 10:08 am

    Is this the same as Tufuse??

  • Light Stalking March 9, 2009 09:33 am

    I wonder if this is going to start taking the photography world by storm in the same way that HDR got a bit overdone. Don't get me wrong, I love HDR pics but there is such a thing as too much of a good thing. Thanks for the write up.

  • dcclark March 9, 2009 09:10 am

    Very interesting. I will have to try it.

    One of my biggest problems with HDR is not so much a problem with HDR, but with people using it unnecessarily, or at least using it all the time and producing many very poor images. Perhaps if this new method takes off, the images at least won't look as ridiculous!