Photography technique Infrared High Dynamic Range (IR-HDR)

A novel interpretation of a classic theme.

Of the 7 Wonders of the Ancient World, the Hanging Gardens of Babylon remains the most enigmatic, as nobody knows much about them. We can still see the ancient pyramids at Giza, or imagine the brilliance of the Lighthouse at Alexandria or the splendor of the Temple of Artemis near Ephesus. We know the temple must indeed have been spectacular, as the ruined Parthenon in Athens and the extant edifice of the Ephesian Library remain mind-numbing beautiful, and yet they didn’t make the list.

However when Washington, DC hosts the annual Cherry Tree festival, its overarching beauty rivals in loveliness and awe any florid display ever. A gift from the Japanese in 1912, the 3000 cherry trees are revered in Japan for as an apt reminder of the ephemeral nature of life, a temporary prettiness that is soon lost.

And how lovely they are!

For a photographer, the extraordinary display of blossoms can be a frustrating challenge, as no photograph can duplicate the exquisite experience itself. Every photograph is a mere attempt to tell of what was, but you had to be there to see it for yourself!

I have tried several approaches, including experimenting with High Dynamic Range (HDR) and Infrared (IR) imagery. HDR often pulls tonalities to such a high degree, that colors can pop like candy.

This is an example of classic HDR:

Another HDR…

Jefferson Memorial, HDR ©2016 Douglas Christian

Playing with desaturation…

Jefferson Memorial, HDR Black & White ©2016 Douglas Christian

And HDR overlayed over a fully desaturated layer…

Jefferson Memorial. A product of 2 HDR images, 1 color and 1 Black & White, merged by multiplying the color image on top of the B&W image to create a partially desaturated effect. ©2016 Douglas Christian

HDR vs. Large Format Photography:

Without HDR, digital sensors remain limited in depth of tonality a photograph can achieve. By contrast, when film is overexposed to a high degree, a diligent technician can still pull detail from the image. With a digital image, high end tonalities can wash out in total white. HDR greatly broadens the effective exposure range of a digitally captured imagery.

With my 8×10 camera, I could achieve an eye popping dynamic range. I would use negative rather than transparency film to expand that range. With HDR, one can achieve a similar chromatic effect. However, just like cooking, if one puts too much sugar in the food, it’s overpowering. So too with HDR.

To capture the intricate dance of blossoms, something reminiscent of Eliot Porter’s convoluted, micro-detailed, reticulated, large-format imagery, HDR provides a nice solution:

Tidal Basin, Washington, DC, Cherry Blossoms HDR ©2016 Douglas Christian

Infrared HDR (IR-HDR)

I have been experimenting with IR photography, and in a nice coincidence, the IR captures much foliage in light shades close evocative of the blossoms themselves. In order to capture IR proper, I needed to use a filter darker and more intense than a Wratten No. 25 red filter; the opaque Wratten No.72 IR filter fit the bill.

A standard filter factor is bit of a hit and miss, as IR affects a sensor and film a bit unpredictably. Furthermore, focusing for IR is tricky, as IR wavelength is longer than the visible spectrum. My rule of thumb, from when I used IR ASA 400 film, was to shoot at ASA 12, or 5 stops, with a No.72 filter. Sometime, I would adjust as low as 7 stops down.

As you can guess by now, a tripod is necessary to use a No.72 opaque filter. If you cannot use a tripod, then a handheld compromise would be to use a dark red, No.25 filter.

In the old days, manual focus lenses often featured a little red line marked slightly off the center of the lens barrel to show how the focus should be adjusted from visible light to IR light. New lenses don’t have that helpful mark, so one has to guess. A focus at infinity needs to be adjusted slightly to less than infinity to compensate for IR.

To complicate things, if one mitigates the focusing error by stopping down the lens to increase the depth of field, the long wavelength IR may suffer from diffraction resulting from long wavelength passing through a small aperture. I often risk that diffraction nonetheless. Rarely can one get an absolutely sharp image on either end of the aperture scale, due to shallow depth of field when fully open and diffraction when fully closed.

One of the nice accidents of digital photography is that most digital sensors record IR light. Most digital cameras have an IR filter placed in front of the sensor, to cut out the IR light. However the IR filter is not totally effective, which means if one (such as myself) wants to make an IR image without removing the filter (which some specialty shops will do for a small fee), a long exposure time is all that is necessary!

These are three IR images bracketed at 1 stop intervals, taken with a FujiFilm X100 with Fuji wide angle adapter and R72 filter. One can create a fake color IR photo by substituting an IR image as a color channel in a straight RGB image. We can talk about that in a later post, but for now, let’s stick to black and white!

Let’s look at the three IR exposures; normal, +1 and -1:

Jefferson Memorial IR with R72 filter, Normal Exposure ©2016 Douglas Christian

Jefferson Memorial IR with R72 filter, +1 Exposure ©2016 Douglas Christian

These photos were processed into HDR with NIK software sitting on top of Adobe Photoshop and output as a black and white image. Viola, an IR-HDR image!