An Introduction to HDR (High Dynamic Range) Photography

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An Introduction to HDR (High Dynamic Range) PhotographyFor those of you not familiar with HDR Photography, it is quite simply the process of combining multiple bracketed exposures into a single photograph, underexposing for highlight detail and then overexposing for shadows we can capture every last bit of detail from both Details that just arent possible to capture in a single shot. You can explore the galleries of HDR photography HERE and HERE(*note: This is not a photography tutorial. If you dont know how to use your camera, take the time to learn. I cant answer your camera questions. Thanks!)Recently Ive been doing a lot of architectural HDR photography and have had friends ask for a introductory lesson on my HDR method. Let me begin by saying that I am by no means an authority on HDR Photography. I am however an accomplished photographer with a solid HDR skill-set. This lesson will be more of an introduction and springboard into the world of HDR than an in-depth examination of the craft. Like in most other areas of art and photography, there is no right or wrong way, as long as you are happy with your results.Keep in mind that although you can accomplish this effect using .jpg or .tif files from your digital camera, shooting your cameras version of RAW (like NEF for Nikon or CRW for Canon) will yield the best results as Photoshop is optimized specifically towards these types of RAW files when compiling High Dynamic Range images.This lesson will follow my HDR workflow from start to finish and will be using the following programs (or extensions of Photoshop) Adobe Photoshop CS4 (though CS3 will be fine too) Adobe Bridge (not a must, but helpful and comes with Photoshop) Photomatix Pro (download the trial version RIGHT HERE Adobe Camera Raw (also comes with Photoshop)

Considerations When Photographing For HDRIf were going to create an HDR image, well need to start with a set of photos. How these photos are taken will make all the difference in how the final image turns out. Making errors in the photography end of the process will render the rest of this lesson useless, so pay close attention.When shooting multiple files for HDR take the following under strong advisement (Ill touch on a few of these in more detail later):1. USE A TRIPOD! I cant stress this one enough. If your camera wiggles even a little bit, the quality of the whole image will be effected. 2. USE A TRIPOD! Seriously I mean it. 3. Along with using a sturdy tripod, I also use a cable release so that there is no chance my shutter finger is wiggling the camera. 4. DO NOT SHOOT IN AUTO MODE. I use Aperture Priority Mode, but Shutter Priority or Full Manual will also work. I prefer AP because I can more accurately set my depth of field. 5. Focus the camera then switch to Manual Focus so the camera doesnt try to re-focus between shots. 6. Bracket 3 to 9 photographs at 1 stop increments. For most conditions I shoot 5 (-2, -1, 0, +1, +2) in that order.

Taking The PicturesOk, so lets assume youve setup your tripod, attached the camera, arranged your composition and are ready get started. Here are the steps you need to take before hitting the shutter:1. As I said earlier, I prefer Aperture Mode because I feel it allows me to most easily set my depth of field. Every photographer has their preference here, so I wont push mine upon you, but make sure whether youre shooting Aperture, Shutter or Manual that youve got the settings correctly for a standard single exposure shot of the scene. (If youre shooting in Full Manual mode, be sure youve metered for the entire scene so that your bracketing will be correct.) 2. If youre using Auto Focus, this is the time to press your shutter part way down to get the lens focused. Once youre in focus, go ahead and switch to Manual Focus so the camera wont try to focus again during the multi-shot bracketing sequence. You folks using Manual Focus, just do your thing. 3. Make sure youve specified your bracket size in your cameras menu to bracket at either 1 or 2 full stops depending on which it will allow. Photoshop can handle a 2 stop difference in photos for HDR, so if your camera allows for it, go the full 2 stops. Now switch bracketing ON and choose how many images you wish to shoot. I typically shoot a 5 stop range for most scenes unless Im dealing with extreme highlights and shadows. For the scene Ill be using for this tutorial I shot 5 photos at 1 stop increments. 4. Now go ahead and shoot your photos. I use my cameras motor-drive function so I just have to hold down the shutter release and it will take all 5 shots without stopping, but shooting them individually is perfectly fine too. Great, now that youve got your photos, head over to the computer and offload them into a folder (or wherever).Ill be using these 5 images, which Ive shot with the wrong White Balance for illustration purposes. These 5 images are available for download at the end of the lesson if youd like to use them.

Step 1 Opening The Files In BridgeNow that youve got the images safely from the camera to your computer, lets go ahead and open Adobe Bridge and navigate to the folder where weve saved the photos. Everyones got their own arrangement of panels in Bridge, and this doesnt really matter for the tutorial but Im using the Essentials layout for this lesson. The important thing is that you can see all the photos in your photo folder.(*note: If youd like to follow along with me at home and wish to use my files, Ive put all 5 of my RAW files into the download at the end of the lesson.)

Step 2 Identify Problems And Open In Camera Raw For AdjustmentAs I mentioned previously, Ive made the intentional mistake of setting the wrong White Balance in my camera and as you can see, all my photos have a strong yellow cast as they were shot under indoor Tungsten light. Not a big deal since we shot in RAW, but this is an issue we definitely want to fix before we go any further to ensure were bringing the most well adjusted files to the HDR process. So lets grab all these files at once and edit them as a group in Camera Raw so that the White Balance will be uniform throughout the set.Select all 5 files in Bridge by clicking on the first one to select it and then holding down the Shift key and clicking on the last image in the sequence. Choose File > Open In Camera Raw from the Main Menu (shortcut Command-R (PC: Ctrl-R)). This will open all 5 files together in the Camera Raw dialog where well be able to make our changes.When Camera Raw opens, select all the images by either clicking on the first and holding down Shift while you click the last like we did in Bridge, or by simply pressing Command-A (PC: Ctrl-A). Or, I guess you could just click that Select All button at the top of the thumbnails column. ;)

Step 3 Make The Camera Raw AdjustmentsWith all your images selected in Camera Raw its likely that youre seeing the preview for your first underexposed image, which probably isnt going to be the best one to look at when were making changes since its so dark, so to switch to another thumbnail without changing our Select All, hold down the ALT key and click on the thumbnail youd rather use as the preview.Now were all set to make our adjustments. Im just going to change the White Balance to Tungsten since thats all this image really needs, but if you wanted, you could change many of the other ACR settings relating to color except the things in the Exposure/Recovery/Fill Light/Blacks/Brightness/Contrast area of course, because we need those to remain intact for our HDR process. When youre done, just click the DONE button to return to Bridge.

Step4 Initiate Merge To HDRWhen you click the DONE button in Camera Raw, you will be returned to Bridge and youll notice that all the thumbnails automatically update with the changes you just made, and that they are all still selected. Were now ready to merge these files together and officially begin the HDR process.From the Main Menu choose Tools > Photoshop > Merge To HDR. This will initiate the HDR Plug-In inside Photoshop and will open Photoshop if its not already running. Photoshop will load all the images into a single file, run through its process (this may take a minute or two depending on file size and how fast your computer is) and it will then open the Merge To HDR window. Yes, your photo will look like total crap and youll wonder if youve done something wrong. Settle down, everything is fine. What youre looking at is a 32bit image that cant be viewed properly with your monitor.Leave everything as it is and just click OK so that Photoshop can complete the merging process(*note: On a side note, the White Point Preview in the Merge to HDR dialog is just that, a preview to show you the tonal range of your 32bit file and how much information youve got between black and white. Moving this slider will not effect your HDR image.)

Step 5 Saving The 32Bit FileWhen you click OK in the Merge To HDR window, Photoshop will finalize the merge and will open the 32bit file its created. Dont worry if this image doesnt look good either, again, its 32bit and your monitor cant handle it.Lets save this image as a .TIF file to the same folder where we saved the original RAW files from the camera. Choose File > Save from the Main Menu and navigate to the folder where you saved your original photos. I always name my HDR files after the first photo in the sequence, so Id name this one DRW_9883.tif since DRW_9883.nef was the name of the first photo in my set. Saving in this manner will make it easier to find your files when youve got a lot of photos in your folders. Make sure you choose TIFF from the Format menu and that the Embed Color Profile box is checked and then click Save.When you click Save, the TIFF Options dialog will appear. Choose 32 Bit, None, Interleaved, and Mac or PC depending on your Operating System, leave everything else unchecked and click OK.