High Definition HDR Photography

High Definition Photography is a relative term, but it basically is achieved by using great camera gear and also by breaking a large scene into several sections, and photographing each section separately. This makes it possible for the photographer to get more detailed information on the camera sensor. You can also focus in on each section to get incredible sharpness and depth-of-field. But it also involves a lot of post-processing work. But it is worth it when you print your images at sizes like 40 x 60 and they look fantastic, surpassing the results of photographers using an 8 x 10 view camera.

And this is no exaggeration. Twice I have had professional photographers come up to me at a show and tell me my images had better detail than what they were able to achieve with an 8 x 10.

The first rule to follow when shooting HDR images that you plan to stitch together, is to put your camera on manual exposure. If you were to shoot in aperture priority (which is ideal when shooting only one scene) then every part of your composition would have different exposures, depending on the brightness or darkness of that section of your final image. The HDR process will give you the exposure latitude you need, but you don’t want your highlights coming out as middle gray.

The second rule to follow is to use a tripod.

The third rule to follow is to make sure that you process every image with the exact same HDR tone mapping settings. On this image, I did that, but on the sections that had the rushing waterfall in them, I did two settings.

Let me explain. When I processed the sections that had the waterfall in them, everything looked great — except the water. The tone mapping process brought in too much hardness and contrast, not to mention artifacting (which happens frequently if there is a lot of motion). After some experimenting with the highlight smoothness, shadow smoothness and micro smoothness sliders, I was able to come up with a tone mapping recipe which rendered the waterfalls in a much more natural way. So in Photoshop, with a layer mask, I was able to brush in the desired effect of the water while keeping the non-smoothed effect of the rocks. Here are the two versions, beginning with the undesirable look of the water, followed by the version which is smoother:

Here is how simple that was accomplished in Photoshop:

If you are not sure how to load two photos as separate layers in Photoshop, here is an easy way. Select the images you need in Bridge (or Lightroom), and then go to Tools — Photoshop — Load files into Photoshop Layers. Here is what the menu looks like:

One other important point about using two different tone mapping settings. You need to save the settings so you can go back to them quickly and easily. In Phtomatix, after you process the image, you go to File — Save Settings. Give your setting a name and Photomatix will save them with an .xmp extension.

When you need to go back to one of the settings that you have saved, you simply go the the Presets drop-down menu at the bottom of the tone mapping controls (just above the Process button). One of the options you will see as you scroll down the various presets, is an option for Load Settings.

When you are shooting the several sections that will make up your final image, you want to overlap the images so that Photoshop, or whatever stitching program you are using, has the information needed to align all of the images. I usually overlap the images by about a 1/4 or 1/5 of the image on all sides.

Also, there are several software programs that you can use to stitch together your HDR images (or non-HDR images for that matter). I’ve gotten good results from Photoshop CS3, CS4, and CS5. But don’t try it if you are using CS2. Kids in kindergarten can photomerge better than Photoshop CS2.

Other programs you might try are Hugin, APP, PTGui, Realviz, and Stitcher.

When you are stitching HDR photos together, a logical thing to consider is the order of the workflow. Do you stitch each exposure set into a panorama (all of the 0EVs into one, the -2 EVs into another, the +2 EVs into another)? If so then you would merge all of these panoramas into a single 32-bit HDR file, and then tone map. This is a possible workflow, but it can be plagued with alignment issues.

Another possibility is to merge each section of exposures into a 32-bit HDR file, and then stitch them together before you tone map. You can stitch 32-bit HDR files together in Photoshop CS5. After Photoshop stitches these files together, merge the layers, and save it as a 32-bit HDR file for tone-mapping in Photmatix Pro. Or if you want to tone map it in Photoshop, go to Image, Mode and change the selection from 32 Bits/Channel to 16 Bits/Channel. You can also choose the 8 Bits/Channel, but you will be more effective in manipulation of colors and luminance values in the 16 Bits mode. When you are all done with your adjustments, change it to the 8 Bits mode.

If you change the mode to 16 Bits or 8 Bits, you will be presented with the following Photoshop HDR Toning menu:

I, personally, prefer to do my tone mapping in Photomatix Pro 4, because it offers more control, such as color temperature, and shadow and highlight smoothness, and White Point, and Black Point. And if you too prefer Photomatix, then save the stitched file as a 32 Bits/Channel HDR image and open it in Photomatix.

Also, it should be noted that all of the stitching programs I mentioned earlier can also read and stitch 32-bit HDR files. My experience in proceeding in this workflow is that the 32-bit stitched file created is too big and it can sometimes crash the computer.

What I find that works best is to merge the files of the different EV values, then tone map them all with the same settings, save them as 8 Bit (or 16 bit) files, and then stitch them together. But before doing all that work, I usually do a test stitch of all of the 0EV files. More than once, I have tone mapped nine different files, only to discover later that the images (for some reason or another) couldn’t be aligned.

Anyway, this final image was comprised of six triple exposures. By the way, I merged, tone mapped, and then stitched.

Here is the final version: