David Saffir: Managing Dynamic Range In Post-Production
Jun 2013 06

I discussed capture management processes in the first two parts of this series. In this segment, I’ll review a method you can use to manage dynamic range in post-production, focusing on use of the white and black face of the SpyderCUBE.

The SpyderCUBE is fabricated from a spectrally-neutral hybrid resin, which is through-pigmented and is highly durable. The spectrally-neutral bit is very important; it ensures accurate color balance under any light, or in mixed light. One of the other things I particularly like about the SpyderCUBE is its 3-D design – it’s always easy to identify the primary light source: just look for the brightest face on the right or the left of the device. (Note the difference, right vs. left, in Figure 1, below).

Figure 1

I normally place the SpyderCUBE in-shot once I’ve completed my lighting setup. As I’ve said earlier in this series, I can also use the SpyderCUBE to evaluate exposure, set in-camera white balance, and establish neutral color balance.

It’s important to ensure that the SpyderCUBE is illuminated properly – in most circumstances, I place it near the main subject, ensuring that primary lighting sources are not blocked and that it receives the same illumination as the main subject. In some cases, I’ll use my hand-held light meter just to the front center of the main subject, and the SpyderCUBE, to make sure they are receiving the same light exposure.

The first capture will include the SpyderCUBE, and then it will be removed from the set. Normal image capture begins at this point. If I make a lighting change, I’ll reshoot the reference image, and of course include the SpyderCUBE.

Figure 2

In this case, I used three lights: a large softbox as my main light, and two secondary lights to fill in the cavity in the machine (to camera right) and for front fill on the machine operator.

From this point forward, I’ll describe a Photoshop-oriented RGB workflow; intended output would be to a wider-gamut inkjet printer, using luster or glossy paper. Fine-art, baryta, matte, or watercolor-style inkjet papers will be discussed in an upcoming post.

  • Open the image that includes the SpyderCUBE in your RAW processor, and treat as usual, using the eyedropper on the gray face of the SpyderCUBE to set neutral color balance. Save these color balance settings (along with others you may have made) and apply them to other images in the set that used the same lighting setup.
  • Export/save a high-bit TIFF in a color space like Adobe RGB for post-production editing. I don’t recommend using sRGB for this purpose. Open the image containing the SpyderCUBE and at least one of the other images in the set in Photoshop.
  • In the SpyderCUBE image, create a levels or curves adjustment layer. Using the black and the white eyedroppers (these are outlined in red in Figure 3), set the black and white points for the image by clicking on the corresponding faces of the SpyderCUBE (blue arrows). Use the brightest side for the white face.

Figure 3

  • You can customize the black and white points to yield greatest dynamic range on paper (preserving as much shadow/highlight detail as possible).
  • Double left click on the black or white eyedropper, and you’ll see a dialogue that looks like this (Figure 4). Note the blue outline around the RGB values. For the white eyedropper, type in RGB values of approximately 245, 245, 245. This will help preserve highlight detail in the majority of photographs. Click OK, and then “Yes” to confirm. Repeat for the black eyedropper, but set the RGB values between 6 and 9, which should give good blacks and protect shadow detail in the print.

Figure 4

  • You can save these adjustments by clicking on the indicator at the top right of the curves dialogue. Use the “Save Curves Preset” feature. You can also apply these adjustments to your other image(s) by opening a curves adjustment layer, and using the “Load Curves Preset” feature. (Figure 5)

Figure 5

The adjustment values provided here are middle-of-the-road, or average values. You may want to experiment with small adjustments until you get right look and feel in terms of dynamic range on different manufacturers’ papers. In some cases, you’ll also find it is helpful to re-adjust color balance using the gray eyedropper on the gray face of the SpyderCUBE.

Here’s the final image chosen, corrected, retouched, cropped, and ready for prime-time:

David Saffir is a commercial and fine art photographer and printmaker, located in Southern California, and a well-known speaker at workshops and conferences across the US.

  • Mark Rosen

    Can you use the cube in light room?