January 09, 2010
*Remember, if you know how to do any of this feel free to skip ahead, I have tried to make this tutorial helpful to everyone, from those who have never heard of or seen and HDR image, to those that have made 100 and are wondering if there could be something more to make their HDR images even better.*
HDR or High Dynamic Range is a technique that utilizes multiple photographs of the same subject under different levels of exposure that are then combined or merged together to create one image containing the range of multiple images. It is achieved by converting the images to 32-bits, allowing more range in a single image.
There are multiple variations to the capturing and processing of the image, but I will go over the most general method, and talk about variations at various points.
To get started you will NEED
Digital camera or dSLR with Manual mode or a mode to adjust based on EV.
Post processing software. I personally recommend Photomatix Pro 3 (or older versions) and that is what I will be using for the tutorial. Photoshop has HDR functions but they are less user-friendly, and yield worse results.
Things to help the process but are not required
Tripod- This is right on the fence between need and recommended. A tripod will aid in steady shots that line up perfectly, which is needed, but a steady hand and post processing can replace a tripod. Bean bags, monopods, gorillapods, and any steady surface can provide great substitutions.
Shutter Release Cable- Just a recommendation, this will ensure that you do not move the camera at all when adjusting exposure or hitting the shutter. Even the faintest most gentle press of the on camera shutter control can lead to slight movements that throw this delicate process off.
How to set up
First choose your subject and how you will compose the shot. *The less movement the better* Remember HDR is built upon combining different images of the same subject, so if your subject is moving, it will not work as well. Background trees are ok, I recommend trying to use faster shutter speeds to avoid motion blur. Water also generally smooths out with the combination of shots, but overly rough waters will probably yeild poor results. Therefore use something that is basically still. Make sure to look around before you start shooting. One to many times I've had a set of shots ruined because somebody walked across my shot.
Now get your camera in Aperture Priority Mode, or Manual. Remember here is your time to think about the shots composition. If you want a shallow depth of field to make your subject pop, use a wide open aperture (this will also aid in faster shutter speeds to avoid motion blur). If you are looking to get the hyper-real with the entire shot in focus, use a smaller aperture (for tips on getting your entire shot in crysal clear focus, message me). Finally, locate your EV scale. I'm pretty sure 90% of cameras have a range of -2 to +2. This is the same scale that you generally aim to get 0 on, for a "balanced shot". It looks something along the lines of ...
-2 | | -1 | | 0 | | +1 | | +2 EV
Basically your goal is to, get the exact same shot, in every integer. Therefore you are looking for 5 total shots (-2,-1,0,+1,+2), It works best to either start at -2 or +2 and work your way to the other max. So keep the same aperture, same focal length, and same focus for every shot. Everything needs to remain constant except the length of exposure. Adjust your exposure only to get each of the 5 shots.
*Variation Note*- Some people use less range, some people use more. Some people use 15 shots, others use 3. Personally 3 does not stray far from the original balanced image. And 15 is just uneccessary. You can expirement with different amounts, and different increments (go ahead and try taking 15 shots at .333 increments. I feel as though the results are best with the way I have showed you above but everyone is different so don't be afraid to fool around and find out whats best for you.
So now you have 5 different shots, ranging from -2 to +2...
1. Open up Photomatix Pro 3
Choose "Generate HDR"
2. On the pop up menu, select Browse, and find your 5 photographs
3. Select all of them at once, or individually.
4. Hit, Ok, and a new pop-up menu will come up, giving you options.
5. Check all boxes, Align sources by matching features, reduce ghosting artifacts from background movements
6. Wait for Photomatix to do its work.
7. When the not-so-pretty image pops up, choose tone mapping and stay on the Details Enchancer tab
8. SSS. The bigest 3 options to making your photo take off are Saturation, Strength, and Smoothing.
I say bring saturation and strength up to 90 each, and take the smoothing to around -7. These settings will give you that HDR image you want, depending on the natural color and contrast of your photo they may be too extreme. You can fine tune it yourself. The higher saturation, the more bold the colors will be. The higher the strength, the more the halo will develop from each other, and the colors will seperate. Finally the higher smoothing is the more the colors will blend, decreasing the contrast. I recommend a rather low smoothing, but its all a matter of opinion.
9. Once you are happy, process the image, which will return you to the menu, and then save your image.
10. You can then open this in your preferred editing program, I generally take it to cs4 for better control over the levels, and contrast. (A little S-Curve on the Contrast is generally my final move). You can also then apply your favorite actions to your new HDR photo!
P.S. If you refuse to try Photomatix Pro (free trial is available) You can do HDR in Photoshop.
A quick explanation
Open Photoshop, choose File -> Automate -> Merge to HDR
Select Files, let it do its thing.
When you get your image preview, hit ok, then go to Edit -> mode -> 16 bit
This will pull up a pop up menu, at the bar at the top, click the drop down bar, and choose Local Adaptation.
Now create a curve that best shows your images dynamic range. Then adjust the gamma and radius to improve the clarity.
Now when you have a sub par image, meticulously mask and edit the various colors in your image and then curse at yourself for not just trying out Photomatix which would already have you receiving stars on BlueCanvas for your completed HDR.
Some things I suggest trying.
-Convert your HDR images to BnW, the higher range of highlights and shadows can provide some BnW quality that is otherwise unachievable.
-Partial Desaturation, bring the focus on your subject more by selecting its dominant color, then selecting the rest and desaturating the image.
-Cross Processing- message me if you'd like to learn about this technique
When should I use HDR, and when shouldn't I?
There really is no perfect answer for this, but I have a few scenarios when HDR can completely turn your day around.
You've got this great building, and the sun is breaking through the clouds right behind it. As you raise your camera and balance the shot to 0 EV, you realize your sky is a blur of white, and your building is just a shadow. Well drop it down to -2 EV and you got a completely black building, but you can see every detail in the sky. Then bring it up to +2 and sure your sky is a mess of white with 0 detail, but now your have a well lit building and you can capture every highligh of it. Merge those shots to HDR, and you now have the best of both worlds, the glorious sky behind the glorious building...Otherwise an unattainable image.
Photographing a very nice car with a reflective finish? The -2 and -1 EV shots will bring the color of the paint out, wheras the + EV shots will give you the great streaks of natural light.
There are many more scenarios, but you just have to learn yourself when to go to HDR. I do love this technique, and think it's popularity will increase, but I do not think that every shot should be in HDR. If that were the case every image in print would be an unaccurate representation of reality.
Try it out, and feel free to message me with any questions, concerns, or comments.