The Food Photography Blog

HDR (High Dynamic Range) images seem to be the photography fad of the month. The internet is saturated with them, most of them truly awful. And that’s because the photographers (mostly amateurs, of course) haven’t thought about the reason they’re using HDR. Mostly they’re the result of inept tone mapping to give a totally unreal effect (unreal as in completely outside reality, not as in ‘cool’). That is, they’re not actually expanding the dynamic range at all; rather they’re creating - no, that’s the wrong word - ending up with images that, in more competent hands, would have a fine-art appeal.

The same can be said of panoramas. Ever since Ken Duncan started his gallery at Avoca on the NSW Central Coast, photographers all around the world have been emulating him by shooting panoramas. At least, they think they’re emulating him; it takes a lot more than a cropped format to make a good photograph, let alone a great one.

Recently I was commissioned by Tamar Valley Resort in northern Tasmania to shoot some panoramas for a new brochure. As winter was coming on, they were anxious to get the images in the can before the bad weather set in. Two weeks later, we finally got a clear day, Tassie weather being its usuall capricious self. And with the fine weather came those beautiful clear blue skies that you get when the weather’s fine in Tassie, the result of the cleanest air on the planet. So in order to hold detail in the deepest shadows as well as the brightest highlights, I decided to shoot for 32 bit HDR files, bracketing 3 stops either side of correct exposure, so bright was the sunshine.

Now, simply to create an image of suitable resolution for an A4 fold-to-DL brochure could have been easily created in a single capture but after 30 years as a professional photographer, I’ve learned to hedge my bets and provide them with images of suitable resolution for pretty much anything they could possibly want. So I decided to use my new Gigapan head to create a multi-exposure panorama. The final resolutions were in the order of 35 megapixels and around 200-300 MB each. And that finished, flattened TIF files!

Each final panorama was made up of a total of 35 captures. The methodology was this:
1. Calculate mean exposure. I did this by spot metering the deepest shadows and brightest highlights in which I wanted to hold detail.
2. Set the camera to this exposure. I also used manual focus. Because the shots were quite distant I could get away with f8 and still get the depth of field I needed. This is my preferred exposure for distance work unless there are compelling reasons to go wider or narrower as it provides the sharpest image with my Nikon lenses.
3. Take a manual white balance, not difficult when you’re outdoors and there aren’t any clouds.
4. Set the Gigapan for the number of exposures. Because these panoramas were long and narrow I could get away with 5 images for each with about a 30% overlap to allow the stitching software to do its stuff.
5. Take the first set of exposures. Once the panorama is captured, the Gigapan automatically returns to its start position so it’s easy to reset the exposure and then repeat the panorama. Do this 5 times in order to capture the exposure range.
6. Back in the production area I created the 5 separate panoramas for each finished image and then did an HDR merge of each. When I put the finished HDR panoramas together I found out that this didn’t work. Somehow I managed to get ever so slight image shift between each of the HDR panoramas, evidently due to the software - probably a floating point calculation error or some such thing.

Now image processes like these take a lot of computing power and therefore a lot of time, so finding out the process didn’t work was a little frustrating. No matter. I switched to creating the HDR merges first and then merging the final HDR images into the panoramas. This worked just fine, while I went and had lunch. Coming back after lunch, I found the first panorama was just as I’d hoped. A little cleaning up with Noiseware (always do these processes after the merges or you risk differences between the merged images), some contrast work and sharpening and the images were ready to go off to the client.

In all I captured some 14 HDR images, 8 of which were stitched panoramas. The client was delighted and had not the faintest clue as to the complexity of the job that delivered such high resolution images with a large range of tones into their hands. Now I’ve just got to hope the printer doesn’t screw up all that work!