The problem, The Equipment, and the How-To

The problem…

Grab a digital camera and take a picture of a painting.

What you will end up with falls short of the images you see in art magazines, or art books. Photographs always fall short of communicating the full breadth and scope of a painting, even when they are very good. What you can’t get is a sense of the materials and the texture, you can’t get the size, or the detail and depth of the painting continuing back through the edge. What you can get is a sense of the color and the luminosity of the paint, of the shapes and colors, and a sense what the painting might be like of you were standing in front of it.

But that digital snapshot most likely won’t do that.

I started with an Olympus D490 2.1 mega pixel digital camera.

The first pictures I took of my paintings were much better than nothing, and because I could enlarge and tweak and crop and do all of the things digital allows, they were better than the shots I got with a 35mm camera. But they showed glare, or the light wasn’t quite right, they looked dull. They might be blurred from camera shake, from hand-holding the camera for the shot. They might have digital noise, because the camera increases the sensitivity to compensate for the lighting, automagically.

I knew the quality I wanted. I figured out how to get it consistently. This is how.

I drew information from two books.

The quick and easy guide to Photographing Your Artwork, by Roger Saddington (ISBN 1-58180-283-8). And

Photographing Your Artwork, by Russell Hart (ISBN 1-58428-028-X).

I would recommend both of these as guides, and if you sculpt or work in three dimensions you’ll need to go beyond the application I have here. These two books will give you a theoretical understanding and a higher level of competence in getting the image you want. They cover in more detail camera exposure information.

Sorry, but you’ll be spending money. Go used camera equipment if you need to cut costs. I can recommend keh.com without reservation if you are in the USA. Their “bargain” level rating is equivalent in most case to other sites “good” or even “excellent” rating.

Get good stuff. You should be using it in any case to capture images for use in your art.

Equipment:

• tripod. I use a bogen/manfroto 3001BN tripod, with a bogen/manfroto 3030 3-way head.
    

  A less professional stable tripod would work fine, but wouldn’t be as much fun…

• Canon digital SLR. You need a real camera. I started with a Canon 300D and an inexpensive 18-55mm kit zoom lens, and I got very good results with it. I currently use a Canon 30D with a 24-70mm f2.8L series lens. You don’t need an L series zoom, I got that for other photographic purposes, and because I dearly love really elegant engineering. Least expensive would be the current Canon 400D and a 50mm lens.
    
  The 50mm lens is inexpensive, a plastic housing, and outstanding imaging for the price, about $80.00. Far better than the kit zoom lens. Slightly better and slightly more cost would be a 28mm lens. Nikon would work, as well. Originally Canon started the under-$1000.00 digital SLR market. Now there are some very good Nikon models at the same price point. I stuck with Canon.
• A memory card appropriate for your camera. Best price point right now is 2 GB. But that keeps changing…
• Remote release. These are specific to the camera, electronic switches that allow you to eliminate shaking from pushing the shutter with a finger.
• Circular polarizing filter, appropriately sized for the lens you are using.
• An easel. This holds your painting straight and level.
• Cloth backdrop. I’ve used black, white and a canvas painter’s drop cloth. A white wall would work. IF you take slides, actual film, this becomes more critical, as you won’t necessarily crop to the painting, but have a background visible. You’ll need to work out hanging it. I sewed web loops at the corners and in the middle and hung the cloth behind the easel with nails and bungee cords from the rafters of my studio.
• Two poles. I have two “3rd Hand” construction poles,
  
  which adjust and clamp between floor and ceiling. You can buy light stands on ebay that would probably work, or rig up a home-made stand with schedule 40 pvc plastic pipe – probably 1-1/4″, it is stiff enough to work with. You need a method for hanging two lights at about 4 feet from the ground, so what you want is a vertical pole at about 5 feet in height from which to hang the lights stably. The lights are heavy and they get hot. You want them to stay put.
• Two 500 watt construction lights.
  
  These are halogen lights. They get very hot, did I mention that? Take care with them, be cautious with them. Cloth draped directly onto them would be a fire hazard. Leaving them unattended would be a serious mistake.
• looped bungee cords – the kind with a ball secured to one end, about 12″ long
  
• extension cords, heavy duty, two of ’em.
• plug strip
• polarizing film.
  
  adorama sells a 17″ x 20″ sheet. This is a sheet you will cut and place in front of the lights and is key to eliminating glare completely. If you are not handy, adorama also sells a 12′ x 12′ cardboard framed filter, pictured above, you would need two of these… I used to build cabinetry, so I built my own frames of oak, and cases in which to store them safely, out of the dust and out of harms way.
• an 18% photo grey card (kodak makes a cardboard 8 x 10 sheet – there are plastic ones that are better, but I still have and still use the cardboard one as well…). This is just a card coated to match the average grey that light meters look for to get a correct exposure…
• OPTIONAL – a light meter… yes, a light meter. Be thankful you don’t need a flash meter. Least expensive reasonable quality meter I’ve found is Sekonic L-208 Twin Mate. And B and H Photo Video is an outstanding source for good equipment.

Theory, or here’s what you are trying to accomplish

The key seems to be eliminating glare to enable a saturated true capture of color and form. Here are two images…

A non-polarized source lighting. This is more than likely the flaw in most snapshots of paintings.

Polarized – this is polarizing film over the halogen lights, and a circular polarizing filter over the lens of the camera.

Once you see this difference you’ll start spotting it on photos of artwork all over the place. Usually it looks like a mistake and it distracts from the presentation of the work. I have a couple of very heavy layered paintings. Photographing them works when done as I am outlining here, but only the detail shots, much closer than the full painting, show the depth and texture the painting actually has. I’m still working with lighting to find a compromise that drops all the glare but allows some continued shadow to give a greater sense of depth and texture. But overall lighting through a polarized filter and then adjusting to match that light on the camera itself makes a huge difference.

This is mentioned in Russell Hart’s book Photographing Your Art Work on page 99 (ISBN 1-58428-028-X):

Polarizing Filter. A polarizing filter does the same thing for color film that a yellow filter does for black and white, deepening blue sky. But it is more useful, in both black and white and color, as a means of controlling and eliminating unwanted reflections. It works the same way as Polaroid sunglasses, minimizing the glare that can occur on the sides of high-gloss or heavily textured paintings, even when they are carefully lighted. (It is also useful in reducing glare on cracks and crazing in older paintings.) A polarizing filter will not, however, eliminate a direct reflection; the angle at which the light glances off the surface must be oblique. And because the filter is actually a microscopic grid, it must be oriented in a certain way relative to the light source in order to work. For the reason, it’s designed to be rotated in its mount, and the effect of that movement can be observed through the camera’s viewfinder. Turn it until glare, or an unwanted reflection, is at a minimum…

…The polarizing filter is even more effective if used in combination with polarized light sources… [emphasis added]. You can polarize your lights by placing a sheet of polarizing film… …in front of them… …keep the sheet far enough away from the lamp to avoid melting or burning it…

Again. Treat these lights with care. They get hot.

You want two light sources approximately 7′ away from your painting at a 45 degree angle to each side. The light sources are 500 watt construction lights, set at approximately 4′ off the ground. In front of these two lights is a polarizing film, close enough to cause the light falling on the painting to pass through polarized, far enough away to remain cool. In my experience, this is 6″ away from the glass front of the light. The lights are connected to a plug strip. The switch on the plug strip turns the lights on and off as a pair.

The two sources eliminate a lot of glare and shadow. Polarizing the light by using a polarizing filter in front of your source lights and then a polarizing filter as well on the lens of the camera allows you to control the rest of any glare or reflection. The polarizing filters in front of the lights are linear – they have a directional axis – both must be oriented the same direction. Doesn’t really matter which direction, horizontally or vertically – but they must orient the same consistent direction.

You will have set your painting on your easel holding the painting so that the center of the painting is equal to the height of the lights, approximately 4′. The painting should be held plumb, that is straight up and down without a tilt back or forward.

Behind the easel is a backdrop cloth, or wall, creating a consistent non-distracting background.

Approximately 6 to 8 feet in front of the painting is your digital SLR camera, set to manual mode. It is on a stable tripod, set horizontally or vertically framed according to the painting shape and orientation. Attached to the camera is a remote trigger. On the front of the lens is a circular polarizing filter.

Your camera is set to capture in RAW image mode. Not jpeg format. RAW capture. A RAW capture is the full set of information from the camera sensor, like a digital negative. If you capture jpeg format images you are getting an edited reduced version of the image – much less information, much less editable or correctable. This is true of all digital photography. Learn to use RAW images.

Your camera lens is at the center of the painting height. The camera is level and square to the plane of the painting. It is not pointed up to the painting or down to the plane of the painting.

You place the photo grey card in front of the surface of the painting. Remove the camera from the tripod, and disconnect the remote switch. Set your Canon camera to P. Set the lens to manual focus. You can focus on the edge of the grey card or set the focus to approximately correct from the scale on the lens. Doesn’t really matter, at this point you are reading the light, not taking a photo. From far enough away to not be blocking the light sources (your shadow doesn’t fall on the grey card), fill the frame with the grey card, and press half-way down – read the shutter speed and lens aperture. Rotating (again, this is Canon) the small wheel just behind the shutter button in setting P will change the shutter speed and lens aperture in combination – adjust this wheel until the lens setting is f8. Read the shutter speed.

Most camera lenses are sharpest at a couple of f stops down from the widest aperture. For example an f 2.8 lens has a widest aperture of 2.8 – two stops down would be f5.6, three f stops from widest would be f8.

Sigh. Camera theory. You have three ways of controlling light. ISO, how sensitive you make the digital sensor, or what sensitivity of film you place in your film camera. How fast the shutter opens and closes, measured in fractions of a second. And finally, how much light is allowed to pass through the lens of the camera. This last is controlled by the size of the aperture, the hole in the middle of the lens, and the designated measurement for that aperture size if the “f-stop”. On an “f2.8 lens” 2.8 would be wide open. You want f5.6 or f8. This will result in a shutter speed quite slow, perhaps 1/4 second in some cases. Hand holding a camera at that shutter speed results in a shaky image. That is resolved by putting the camera on a tripod and using a remote trigger.

You can also lock up the mirror and then trigger the shutter. See the camera manual for instructions.

The optional light meter would give you a precise check on exposure. You can read incident light (light falling on the canvas, with the meter pointed toward the camera. You must compensate for the polarizing filter, approximately one-and-a-third f-stops. What ever the reading is, say f5.6 at 1/15 sec, you need to add light with the shutter speed being slower by 1-1/3 stops, roughly 1/6 second. Or shoot at 1/8th and 1/4th seconds and bracket your shots… Some of this is dependent on the limits of the camera.

Photography isn’t an exact science – wait, that’s wrong. It IS an exact science. But the application will depend on the engineer’s interpretation of that science and what limits he put on the light box (camera). You won’t be designing a lens to accept the exact light you want. Stanley Kubrick did exactly this – to film a scene by candlelight he had built an f0.7 camera lens. You most likely won’t be doing this, you’ll be operating within the design limits of the equipment you have.

To compensate for the blockage of light by the polarizing filter you will need to add as close as you can one and a third stops of light, either by slowing the shutter speed further, opening the lens up (less desirable – we want to hit the sharpest apertures for the lens…), or increasing the sensitivity of the digital sensor (ISO – also less desirable. The higher the ISO setting on a digital camera the more noise your image will have…). When you meter using the camera, you are metering through the lens and through the polarizing filter, so that compensation is already made.

So why use a light meter at all? That’s why I listed it as optional – you don’t have to. But understanding how to use it results in a better understanding of the nature of light and how it affects photography. And if you take this process a couple of steps further and shoot medium format slide film to scan for limited edition prints, those medium format professional cameras are manual. And for those you need a light meter. And you’ll be compensating for the filter or filters by hand.

So you have your reading for shutter speed and lens. Place the camera back on the tripod and reconnect the remote switch. Set the camera to manual and set the shutter speed and lens aperture to the reading you got from the 18% grey card. Your camera manual will tell you how to make these settings – they vary slightly in operation even among Canon camera models.

You can focus automatically or manually. Some paintings require manual focus. Start by trying automatic focus. Press halfway down on the remote switch to cause the camera to auto focus. If it finds focus easily and doesn’t search back and forth to find focus, autofocus is going to work. If it has to hunt back and forth or can’t find a point of contrast to use to determine focus, you’ll have to set the lens on manual and do it by hand.

Look through the camera viewfinder. Turn the polarizing filter until the glare goes away and colors become saturated and clear.

Take the picture. Adjust the shutter speed up one stop. Take a picture. Adjust the shutter speed down two stops (one stop down past the correct setting). Take a picture. You have bracketed your shot. One exactly as measure, one with one stop more light than measured, one with one stop less than measured as correct.

Leave the set up in place. Remove the memory card and transfer the files to computer. Open them in your photo editor (at least Photoshop Elements). Check your result.

To edit RAW camera files effectively, Real World Camera Raw with Adobe Photoshop CS2, by Bruce Fraser, ISBN 0-321-33409-4 is outstanding. . To edit photographs in Photoshop, The Photoshop CS2 Book, by Scott Kelby, ISBN 0-321-33062-5, will give you the tips and tricks to doing a professional job within photoshop after you have saved your RAW images to tiff format. I use at this time CS2. CS3 is out already, and I’m sure over time these programs will change considerably – adjust this to your current software. The basic concept is to shoot in RAW format, to get sufficient data to work professionally with those RAW images, and then to learn to edit those images within your software at a professional level.

Re-shoot if needed, adjusting focus, shutter speed, polarizing until you have the image you want to capture the spirit of your art and promote it effectively.

Next:

More on the set-up, Extending this to film and slides, and Images, many, many images… organizing and backups

to be continued…

— spence

artist@spencemunsinger.com
spencemunsinger.com