A DIY Calibration Chart for Photographing Your Art (No Expensive Gear Needed)
Ever taken a photo of your artwork only to have it look completely different once it's online? You're not alone. Professional calibration tools from companies like X-Rite or Datacolor Spyder can help fix this, but they're expensive and actually only work on devices you control. The real problem is you have no control over how someone else's screen displays your image.
So, I created a simple chart to tackle the biggest issues that come up when photographing art for the web. It’s a low cost printable calibration chart you can use any time you photograph your art to be shared on-line.
Download the chart (as a .jpg file) and print it at 4 by 6" (10 by15cm) on photo paper. Choose matte or semigloss over glossy to avoid reflections. Any inkjet printer works, or take it to a photo print service like Ted’s, Officeworks or Harvey Norman.
You can use the chart before you shoot, or after, when editing. Fixing lighting issues before you shoot saves time and gives better results overall. Just place the chart on or next to your artwork, under the same lighting conditions.
Why Dynamic Range
Matters
Dynamic range describes how much detail a camera captures from shadow to highlight. Your eyes handle huge contrasts easily, from sunlight to starlight, but cameras struggle. That's why bright skies blow out to white or shadows go pitch black in photos.
The chart has grayscale steps down each side, each representing a 2 percent shift in light intensity, plus small target circles for finer detail. The more steps you can distinguish in your photo, the better your lighting is working. If steps disappear into the background, especially on the darker side, add more light, but don't overdo it or you'll blow out the highlights.
This trick works after the shoot too. Use your photo editing software's exposure, contrast, and shadow/highlight sliders can make changes on your photo containing the chart, then copy those settings to the rest of your batch. Thus you only need the chart in one reference photo per series where all the photos are taken umber the same conditions
Colour is trickier than tone. Our eyes adapt to lighting variations automatically; cameras don't. The chart includes seven reference dots, six colours plus black, representing the core building blocks of the sRGB colour space used in jpeg files. The table below show how each of the tiny coloured lights (red,green,blue) on your TV screen of computer monitor are lit up to get the given colour. Zero indicated the light is off and 255 that the tiny light is fully on. These lights then make up a single pixel within the photo image.
(255,0,0) R 0 Red
(0,255,0) G Green
(0,0,255) B Blue
(0,255,255) C Cyan
(255,255,0) Y Yellow
(255,255,255) M Magenta
After taking the photo, you could use a colour picker to compare your photo's dots against these values. This
won't give you pixel perfect correction, but it'll reveal a colour cast. The
main thing to watch for. Do the dots still look clean and bright, or dull and
grey?
Dealing with A Colour Cast
Colour cast is
sneaky because your brain corrects for it automatically without you noticing.
Old incandescent bulbs throw a yellow-orange tint; overcast daylight can add a
blue tint. Reflections from walls and furniture are often the biggest culprits,
since your brain filters these out but your camera doesn't.
To check for colour cast, look at the white background behind the chart's colour temperature panel. If the white looks yellowish or bluish instead of neutral, you likely have a bias. The nine squares can help confirm this.The three colour squares of the same colour as the bias will appear brighter and/or stronger, while colour on the opposite side will appered duller or darker.
The fix is usually simple, find better light. If using artificial light, Daylight LED bulbs (around 5000k) are cheap and reliable. If using natural light, shoot in soft shade rather than direct sun, like near a window indoors, under a veranda, or in an open garage. A white board opposite your light source can bounce light back and soften harsh shadows.
When editing, use white balance, warm/cool sliders, HSL adjustments, or LUTs, always test these changes on your reference photo first before applying to the batch.
One Final Tip
Avoid the saturation slider orfilters when photographing art. They can make your image look garish, especially on screens where the viewer has already boosted their own contrast and saturation. If colors look flat, use the vibrance slider instead, and go easy with using it.
With this one printable chart, you can catch lighting and colour problems before they ruin your photos, and fix them quickly if they slip through. No expensive gear required.
