Mini HDR Tutorial-ish Thingy
I promised someone I’d either write a brief description of how (in the general sense) HDRs are done or point them to other tutorials. I decided to do both and provide a (hopefully) brief write-up. I know before I even start that I always feel like I need to clarify and expound on things too much (I need an editor). For some of you this will be basic, basic, basic. Others just learning about HDR or photography in general will feel like I’ve skipped all sorts of things they need to know. However, I just don’t have the time, nor the skill probably, to make a great tutorial for everyone and I think others have done that anyway. I don’t plan to go into much detail about the when and why to use HDR techniques (or what the technical definitions of “HDR”, “tonemapping”, etc are). I’ll provide some links to other tutorials at the end of the post. Those of you who read this feel free to add other links in the comments.
One note that I’ll start off with is that the definition of a “good” HDR is completely subjective. Same with any other photograph and I don’t get why people still argue over whether a photograph is good or not. You either like it or you don’t…your own opinion is what counts. With HDR in particular there’s this religious aspect to it where some worship and others scorn. Within the group of photogs who dabble in HDR there’s even religious debate. How many exposures to use? When should you use HDR and when should you not? When is “tonemapping” the proper term to describe the process versus the term “HDR” (yeah, I really saw someone go off on that topic — probably the same people who argue over using the term “kleenex” instead of “tissue”)? I don’t mind if some people want to be all technical about it. They just shouldn’t get so hot and bothered about those of us who don’t care about the technicalities. A good HDR is one *you* like. For example, on a popular HDR site (http://hdrspotting.com) I think that many of the editor’s picks are awful. However, that’s just my opinion and it doesn’t matter if others’ opinions differ.
Brief definitions: HDR = high dynamic range. Tonemapping = something the Photomatix software does when it munges your images together. That’s as far as *I* want to get into that.
My idea of when to shoot multiple images at differing exposures (“bracketing” your exposures): Whenever you want. HDR techniques can result in really cool images even when the dynamic range isn’t all that “high”. Maybe you can get the same result from a single exposure, or two exposures. That’s great, but digital film is cheap and it’s nice to be sure you’ve got the exposures you want.
Here are three exposures I’ll use for this tutorial (I actually used 7 exposures for the final image but I’m trying to keep it simple-ish):
Note that in the dark exposure the sky is nice and blue and the sun isn’t blowing everything out. In the center exposure you’ve got decent exposure in the pasture beyond the cabins, some detail in the trees and leaves, and what I consider good exposure in the shadow areas (ie they still look like shadows and aren’t over-exposed). The lightest exposure provides more detail in the shadows. Again, I actually used 7 exposures for this image so that in every area of the frame I would have good (an entirely subjective term) exposure in at least one of the images.
My typical steps after importing my images on the computer:
1) Slight tweaks in Adobe Lightroom. I might do small contrast/exposure adjustments. I usually attempt to fix chromatic aberration.
2) Open the original exposures in Photomatix (I go directly from Lightroom to Photomatix) and tonemap to get a starting point for the final image. There are all sorts of settings and sliders in Photomatix to control what your output image looks like but I’ll leave those for others to describe. I just play with things until I like something. Here’s an example of an output file from Photomatix.
Note that some of the best features of each exposure are retained in this image. The sky is a deep blue, the sun isn’t blowing things out, the view of the shadow side of cabins still look like shadows, etc. Frankly, this output from Photomatix turned out better than many images I do. However, what I immediately see that I’d like to improve is the contrast, sharpness, and the details in the shadows (don’t want to overdo it but I want to bring out more and increase the exposure slightly). For this image, that’s about it. Many times the Photomatix output severely lacks contrast but this one isn’t bad at all. Sometimes the color saturation is messed up…again, this one is pretty close to how I’d like it.
3) In this case I will open Photoshop (PS) with the two brighter exposures as well as the Photomatix output (“open as layers” from Lightroom). My first step in PS is to add a curves adjustment to get the contrast closer to where I’d like it. If you don’t have PS or an editor which lets you adjust “curves” you can just adjust “contrast” (every editor should have that). I would then duplicate my Photomatix layer and use a piece of software called Topaz Adjust to play around with the image to see if it can accomplish that shadow detail/exposure adjustment that I’d like (it often does a great job). I can also do the same thing by using levels/curves/exposure adjustments and mask them in to various areas of the frame. Assuming I get a usable result from Topaz I will then selectively mask that Topaz layer into areas of the image where I want those adjustments made. For this image I used a combination of Topaz Adjust and curves adjustments.
Final tweaks might include noise reduction (not needed here) and more sharpening. I used plain, old “unsharp mask” in PS for this image.
Hope that’s moderately interesting and/or helpful for some of you. For those who haven’t ever messed around with HDR I hope it whets your appetite for trying it out. I listed a few links below. These are off the top of my head and there are many more where these came from…but I’m not going to list more. Search for “HDR tutorial” on the internet and you’ll find plenty of advice. Experiment with it and make images to suit your own tastes.
http://www.nomadicpursuits.com/ (link on right side)
http://davewilsonphotography.com/ (tutorials link at the top)
http://places2explore.wordpress.com/ (link on right side