Lindsay Elgin Center for Digital Scholarship Brown University Library [email protected]

PHOTOGRAPHING OBJECTS Creating Digital Representations of Three-Dimensional Objects

Camera|Equipment Digital camera: point & shoot or SLR (interchangable lens) It's better to use an SLR camera if it's available, mainly because SLRs afford greater control over focal length and focus, and they are more likely to record in the RAW format. But a point & shoot will do in a pinch if you pay close attention to your settings.

Tripod (this is a requirement) Generally, any tripod is better than no tripod at all. It doesn't matter how much light you have or how light your camera is. You must use a tripod. Make sure to find a tripod that is big enough to support your camera.

Gray card/color card You can use a gray card for exposure (18% gray card) or for white balance (32% digital gray card) while you are shooting. You can also include an 18% gray card or a color card into one of your shots for use in sampling in Photoshop for both exposure and color balance.

Polarizing filter is is a filter that attaches to any threaded lens. It absorbs light coming into the lens at a certain direction (polarity), thereby reducing reflections. Make sure you get the correct size, in mm, for your lens.

Camera|Setup Resolution In your camera, resolution is measured using the total number of pixels in width by height (i.e. 3504 x 2336). Regardless of what you plan on using the images for, always shoot at the highest resolution that your camera is capable of. You can always downsample later.

File Format JPEG : e most common file format for digital images. But they use compression, and degrade image quality, so unless necessary always shoot in the RAW mode. RAW: Available on most SLR-type cameras, the RAW mode is uncompressed, and is a file that captures the images exactly as it comes off the camera sensor. It affords much better flexibility for adjusting exposure and white balance in the processing stage. Use this whenever possible.

Exposure It's essential to get as close to the correct exposure as possible. Too much light and the highlights will be forever blown out. Too little, and your shadows will never have detail, and your image can be plagued by noise. You must control your exposure.

Exposure Compensation (also referred to as Exposure Value, or EV) Used in the program and some auto modes of digital cameras, this allows you to override the camera's exposure and purposely under- or overexpose as you see fit.

Camera|Setup, cont. Shutter Speed Controls how long the shutter is open for; i.e. how long light is let into the camera for. e longer the shutter speed, the more likely you will have camera blur. Not an issue if you are on a tripod.

Aperture Controls the size of the opening of the lens, and by extension the amount of depth of field/depth of focus in the image. Measured in f-stops, a larger aperture (smaller number, i.e. f3.5) gives less depth of field, while a smaller aperture (larger number, i.e. f22) gives more. Usually, you want as much of your object to be in focus as possible, although you may want to use a more shallow depth of field so that you can use selective focus.

Focus Focus is hugely important in portfolio work, and it's not something easily correcting in processing. You can add a minimal amount of sharpness, but you can't simply generate focus in Photoshop. Even point & shoot cameras offer a manual focus setting, and you should use it. If you have difficulty focusing, user either the distance readout available on many lenses/cameras, or print out some large type, insert that into your scene, and focus on that.

Focal Length (Zoom) e focal length of your lens determines your field of view, and also changes the way space is recorded. Wide angle lenses (35mm and below) distort space but allow a wider field of view; telephoto lenses (80mm and above) allow you to zoom in on details but also flatten space. Even if you are using a point & shoot, be aware of our zoom and how it affects the space, including the shape and perspective, of your object.

White Balance Every type of light (daylight, incandescent/tungsten, florescent, flash) has a different temperature (measured in Kelvin) and color. You can set the white balance in your camera in several ways: choosing the type of light you have, setting a specific temperature, or setting the white balance manually using a white reference.

Lighting|Equipment Bowl Reflectors (clamp lights) Any clamp light from the hardware store will do, but the lights with ceramic sockets are safer. ey also allow you to use a higher wattage bulb.

Bulbs You can purchase either specially-made photographic light bulbs or general-use light bulbs. Most ordinary bulbs are rated as tungsten/incandescent, although they don't have to match a specific color temperature standard. Photo bulbs are available in daylight and tungsten ratings, but are very expensive and oen last as few as three hours. Make sure you don't get more powerful bulbs than your lamp will accommodate.

Diffusion material Available at any photo supply store, diffusion material is a special, heat-resistant waxy paper that placed in front of your light. It soens and diffuses the light by spreading it out into a more even distribution.

Foam core reflectors Simple white foam core makes a fantastic reflector. You can use it to bounce light back on an object to help fill in shadow areas. ey're easy and convenient, and can easily replace a light in almost any situation.

Backdrop (construction paper) It's essential to have a seamless, wrinkle-free background behind your subject. Simple construction paper will do the trick. Make sure that's it's clean and that it is big enough to fill the frame of your image, from the wall to the front of the floor/table. Lighting|Equipment, cont. Magnets, straight pins, two-sided tape, weights For propping up and securing your 2-d and 3-d objects.

Tracing paper For shiny or reflective objects, you can make a box/tent out of tracing paper to surround your subject. Arrange the lights outside this light tent, and you'll greatly diminish reflection and create an even light source around the object.

Lighting|Setup Two-dimensional objects (not scannable) Two lights: both must be at the same 45º angle, height, and distance from subject. Generally best to mount on foam core on a wall and shoot, rather than attempt to shoot straight down with object on floor.

ree-dimensional objects Regular models, etc. 2 -3 lights plus reflector(s). Main light(s) light overall object. Reflectors create fill light; fill shadows, show shape of object.

Reflective/shiny objects Use a similar two-light setup as when shooting flat artwork, using a light tent around the object to reduce reflection and provide even lighting.

Processing Your Files Importing your images Import your images however you choose. Make sure that the program you use keeps your original file format and does not change the file size/resolution in any way (iPhoto is a known culprit for converting RAW files to jpeg). Keep track of your images and consider renaming and organizational programs.

Note on scanning Negatives or slides: Scan in at at least 2500 dpi. Make sure to select the correct type of material you are using; some programs allow you to select the manufacturer and type of film/slide. Make sure you clean the film/slide very carefully and remove any dirt or dust.

Non-transparent materials: Scan in at at least 800 dpi. All images should be scanned in in color, and if need be convert to grayscale in Photoshop.

Preserving a digital negative It's always a good idea to keep a copy of your original file that remains untouched. Whether it's a RAW file or a jpeg, keep a copy of the image exactly as it comes off your memory card (jpegs should be converted into TIFFs).

Photoshop|Camera RAW Camera RAW is a plugin for Photoshop that allows you to process RAW images (and, in CS3 and later, allows you to process jpegs as well). is way of editing is non-destructive, and doesn't change the pixel data. You can change the exposure, white balance (including with a white eye-dropper) and shadow/highlight info in the “Basic” tab, and you can tackle sharpening and noise reduction in the “Detail” tab.

Photoshop|General Adjustment layers To adjust exposure/color, use levels or curves adjustment layers, rather than making changes to the image itself. If you have included a gray or color card, you can use the eyedroppers to correct for both exposure and color balance. You can use layer masks to isolate one part of the scene/one element of the object to adjust.

Duplicate layers For sharpening, noise reduction, and retouching, you should be making duplicate layers of your main image and applying your changes to the duplicate only.

Sharpening: Unsharp mask filter, high pass filter.

Noise reduction: Noise reduction filter, gaussian blur filter.

Retouching: Clone stamp, healing brush.

Tips & Tricks Give yourself more time than you think you need. ink hours, not minutes.

Shoot objects that are about the same size or that you think you can light similarly so that you do not need to keep adjusting your setup.

Get all the shots you need (lighting, angles, etc.) before cleaning up your set. It's very difficult to re-create lighting, so avoid that as much as possible.

If you do need to break down a set, you can always mark your tripod and lighting locations with tape on the floor, or draw a map of your setup.