29 March 2015

Accurate Colour Photographing Artwork

Daylight Dance - 11x14" - Oil on board

In the past couple of weeks I've seen a few different artists mentioning frustrations with photographing their art. If you type in "How To Photograph Artwork" in Google you will come up with many, many links to other articles. I do not intend to add to the information already out there, but instead want to address a subject which I rarely see mentioned in other articles on photographing art. How to get accurate colour.

My method of photographing art is a bit more work than many, but I can pretty much guarantee if done correctly you can quit playing around with photo editing programs trying to get your colours to match that of the painting. But I must give a word of caution: there is one aspect of photographing artwork that will be very hard to control - monitor colour calibration. Every electronic device will display colour slightly different, so while you may get a digital image which looks accurate on your monitor, when viewed from work or a friends, it may not look the same. If you want your photos to be 100% accurate you would need to run colour calibration software on your monitor. Although I do this, I don't recommend the average artist do so. The software is pricey and only guarantees accurate colours on your monitor and other calibrated monitors, which are usually reserved to those involved in professional imaging. So work with what you have to be accurate with your system.

You will need the following supplies:

  • A digital camera with full manual controls
  • A large white piece of paper, cardboard or foam core.
  • Artwork
  • Camera manual (optional - but you may need it to find where some settings are located)
  • Tripod (optional but very helpful) 
  • Lighting (optional - but I will not be discussing lighting)

  • This is written for Canon cameras. The procedure is basically the same for Nikons, but the terminology and controls are slightly different. You can use your camera manual or Google "Manual White Balance Nikon (Camera Model)."
First set up your white paper where you will be placing your painting. If you hang your paintings to photograph them, figure out how to hang your paper (tape it, put a hole in it to fit the hanger, or whatever). I don't hang my paintings as I photograph them unframed so I will place them upright on a table or ledge. 

You now need to take a photo of that white paper, but not so fast. You can't photograph it in automatic mode, because camera meters are calibrated to what is called 18% grey (or middle grey). So anything brighter than that will be underexposed, anything darker, overexposed. Turn your camera to manual mode (M on Canon cameras). I like to set my aperture at around f 8.0. The reason for this is it gives a good depth of field that will allow the entire to painting to have good focus - especially if the painting is highly textured as mine so often are.

Now you will need to look at the camera meter and adjust your shutter speed. At some point it will show the correct exposure when the arrow is at the centre mark. You want to adjust this to be properly exposed for the white card. Usually three stops down will work. For example if the camera meter shows a shutter speed of 250, lets reduce that 3 steps to 125. If your shutter speed goes below 100 you should use a tripod as camera shake will be an issue making it hard to get a good sharp image. Now go ahead and take a picture of the white card, but make sure the white fills the entire frame. 

Next we need to use that image to set a custom white balance. Go to your camera's menu and scroll through the settings until you see the option for Custom White Balance. Press set. The photo you just took should appear. If it doesn't you may need to press the left or right scroll buttons to find it. Press set again. A message should come up asking if you want to use WB data from this image. Press okay.

Use the Custom White Balance menu (below highlighted WB option) 

On my Canon camera, I then have to set my White Balance to custom. That option is usually right above the Custom WB setting in the menu. There are several options as seen here, choose the symbol that I liken to a tulip (labelled Custom). 

Set your white balance to Custom (the tulip symbol).
All set. Really, this seems long and complicated, but I promise once you've done it a few times, it is really easy. 

Now to photograph your painting you can choose to remain in manual exposure mode, or set it to Aperture Priority mode (labelled AV on Canon cameras). Leave the aperture at f 8.0 and adjust your shutter speed as needed. Remember that the camera will tell you a balanced exposure setting based on 18% grey. Usually this will be the correct exposure to use, but if your painting uses more dark values or more light values you may need to adjust the exposure off balanced. 

If you are unsure you can always take several exposures, some under, some over and then choose the best one. But really to save time, its' worth learning to judge the value of your painting and adjusting the exposure. So let's say your painting has a large bright sky at about a value 2 on the value scale, and a darker but smaller foreground. The camera meter says a balanced exposure should be 200 at f 8. Knowing the sky value dominates the painting I would adjust the shutter speed down to about 125. 

Again, although this sounds complicated and like a lot of work, you will soon become an expert at it; and you will save so much time with not having to make adjustments after you've photographed your art, and it will be correct almost 100% of the time. Use your knowledge of painting value scales to judge the exposure settings. Values 4 - 6 in a painting, I would use the camera's suggested exposure - anything over or under that, I would make adjustments. 
My non-fancy indoor set up. 

I have tried various lighting set ups, and have never gotten anything that I'm happy with, so resort to working indoors with natural, indirect room light (which always requires a long exposure and tripod); or outside in the shade of our carport. My first step is to set a new custom white balance for each session, because it doesn't matter if you use the same location every time the temperature of the light changes with different times, different seasons, and different sky conditions. So I always start with the custom white balance, then photograph the art, and when I import it to the computer all I need to do to the digital file is adjust it for size.

A Couple Notes:
Make sure to take your camera off the Custom White Balance when you go to photograph something else.
Even if your camera doesn't support full manual exposure, check the camera manual to make sure it doesn't have a White Balance setting.