HDR Tutorial – UNDER RECONSTRUCTION – CHECK BACK SOON!
So I figured that a blog that is more or less devoted to HDR photography should at least have a tutorial on how to do it. Now, by no means do I profess to be an expert. It is all about finding what works best for YOU, and then running with it. I can tell you this much. Your process WILL change over time. You will see other people’s work, you will discover new things in Photoshop and Photomatix, your equipment will change, or you may just change the way you like HDRs to look. I know I have. My very first HDR (and second one) were very natural looking, just because I really didn’t know what I was doing. Then I started to REALLY cook them up, swinging the pendulum way too far the other end for some very heavily processed and strong images. I think I have found a nice balance thought, try to make push my processing to the edge of the surreal, but then tone it back juuuuuuuust a little. You can take a look through some of my images and decide for yourself. Anyways, on to the tutorial.
Now, as we know, modern cameras have a limited dynamic range compared to that of the human eye. Even with the best full frame cameras out they, there are cases where shadows will be complete clipped and highlights will be completely blown out. HDR is here to help you to recover both of these. I will not go completely into the detail behind the whole background of HDRs, my goal here is to help you to produce them.
So the first step is to make sure you have all your equipment. Camera that you can change exposure on? Check. Tripod (or very sturdy surface)? Check. Remote (not necessary, but can come in handy)? Sometimes check. Scene that has a high dynamic range with lots of shadows and highlights? Check. Sort of. Since the goal of HDR was to solve this dynamic range problem, it would make sense that we need to have a very high dynamic range scene. However, through many, MANY trials and errors I have found that I love to HDR anything and everything I can. Even if it is just about pulling the small details out of a picture, or enhancing the colors, I’m in. I do understand that there is an art to capturing this the first time around with one shot, and I am all for doing that on occasion. However, if I have the tools to really make a scene pop, why not?
The camera that I use is the Nikon D40X dSLR as well as a Canon S90 point and shoot. A lot of newer cameras have the auto bracketing feature. This can be very useful in taking the multiple exposures needed for HDRs with one press of the shutter. My Nikon does not have that, so I am forced to manually change the exposures between each shot. Not a big deal, I am used to it, and it will make me appreciate AEB on my next camera! My S90 does have AEB, however it is limited to +1 spacing and 3 shots, which is great if you have enough light. Remember, the goal of the exposures to is to make sure that you have a wide enough range to ensure that both the highlights and shadows are both captured!!
Okay, so I have found a scene I like, with lots of light and shadows. I set my camera on the tripod, put it on Aperture priority because I don’t want the depth of field to change within the multiple exposures and my compose my shot accordingly. For the aperture, I either shoot wide open (f3.5 or 4) if there is not a strong light source, or more narrow (f18) if I am shooting towards the sun. The f18 will give you some great sun rays, which we will get into a bit later. I also leave the ISO at 100 to make sure to leave as much noise out of the shot as I can. So I am composed, focused (both mentally and in the camera) and ready to go. I also change the focus to “Manual” after the shots focus, just to be sure that it doesn’t change as well. I usually start at +5 exposure compensation, and will take 11 shots all the way to -5. Do you need to take 11 shots everytime? Nope. You can get great HDRs at 3 exposures, +2, 0 and -2. I like to take so many because I may not want to use a even number of steps, or I hay very well want to use 9 of the exposures. I find that the more exposures I use, the more even colors I get, as well as less dramatic haloing. I will not get into histograms or anything like that. I figure, I can never go back and look at the scene the same way again, so I better capture as much as I can of it the first time!
Great, you have your exposures, a few are really dark, a few are really bright and some look normal. Now it’s time to start the fun part, the processing.
I use 2 programs in processing my HDRs. The first is the latest version of Photomatix Pro (to create the HDRs) and the second is Photoshop CS4 (for the editing and touch up work). Let’s go ahead and load the original files into Photomatix. Of the 11 shots that I took, I pick usually the middle 7 or 9. There is no use bringing in a picture that is completely dark or completely blown out. For this example I will have used 9. I always shoot in RAW, so when I select and load them, I get this dialog box. You can see the boxes that I have checked. I obviously want the images aligned, and I choose the “Matching features” option, I find that it works best. I also choose the “Reduce Chromatic aberrations” as we as “Reduce noise”. There are some tutorials that have you uncheck the noise reduction, but it comes down to a personal preference. I don’t feel like Photomatix has a huge effect on noise anyways, so I handle that in Photoshop. I also reduce the ghosting artifacts, which I will explain later in the CS4 section.
The RAW conversion settings are the extra options you get when you shoot in RAW. I will usually leave White Balance as “As shot”, unless I didn’t adjust for the WB correctly in my original shots (shame on me!), in which case I will set it to whatever the correct one would be. I always love the color primaries as Adobe RGB.
Now it’s time to generate the HDR!
After a bit of churning and thinking, your un-tonemapped image appears. Obviously this is not the finished product, so we will have to click “Tonemapping” to get it to be where we want it to be. I always use the “Details Enhancer” tab. Chances are the HDR will still not look exactly how you’d like it to at this point, so we need to adjust the sliders on the left. There is no set way to have these. They can even drastically vary based on the HDR you are working with. Here are the ranges that I typically use.
Strength – 40 – 60, depending on how the image was shot. Too little, and I feel like I get a flat look. Too much, and the image is too dark, and you lose some details.
Color Saturation – 45-60 – A lot of changes here are made in CS4, so I will wait to talk about them then
Luminosity – This I always leave to the far right. This helps to reduce halos and to make the bright areas more sharply defined.
Microcontrast – Again, I leave this one to the far right to help bring out the details
Smoothing – This one I leave to the far left for the most part. I can’t see a huge difference in my images when I move it around, but it is all a matter of personal preference.
White point – Always at 10. HDRs have a tendency to darken the scene a bit, and this helps to counteract that.
Black point – Anywhere from 0 – 10, depending on how much contrast I need to bring out in the image.
Gamma – Always 1
Temperature – I usually leave this at 0, but can swing it a bit either way to help the HDR out. I wouldn’t get too hung up on this, because this change can also be made in CS4.
The bottom 4 – microsmoothing, highlights and shadows smoothness and shadows clipping, I always leave at 0.
Ok, so from here I have the HDR looking more or less to my liking. It’s time to save it and kick it over the Photoshop.
Now unless the HDR I’ve created has a bunch of moving things in it (cars, people, flags, etc.) I usually won’t do any masking the HDR. Masking is to help to eliminate the ghosts that motion can bring about in HDRs. Let’s assume that I don’t need to do any of this. I will probably append this tutorial with the soon, but as for right now, we are just talking about HDR creation.
So like I said earlier, I don’t do a whole lot with the colors in Photomatix because I handle them in CS4. The first thing that I do is adjust the color balance to cool off the picture in the colors are too warm or vice versa. I usually desaturate the picture a bit, and raise the “Vibrance” level. This gives me a bit more of a brightly colored shot, without overdoing the colors. I will usually go into Exposure and turn the Saturation down a bit there as well. Sometimes HDR can either give you too cool or warm of an image. If this is the case, then the Color Balance may need adjusting, but this is rare. I also add an “S Curve” if the contrast isn’t quite where I want it. The last thing that I do is add an “Unsharp Mask” or “Smart Sharpen” filter. Be careful not too go too far with these, as you can get too much sharpening and it doesn’t look quite right.
Well, that about does it for this tutorial! I will most likely be adding/changing/revising/adding pictures as time goes on, but this should be enough to get you started! If you have any questions, or would like to know more, shoot me a message through here or on my flickr page!