Let There Be Light


The best digital camera settings for high resolution photos start with file resolution and compression, and four digital photo exposure settings that are automatically set [AUTO], or adjusted manually.

1. File Resolution and Compression. Both of these camera settings determine the size of photos stored on your camera's digital media card. A general rule of thumb is that the higher resolution setting with the least amount of compression is the best for producing giclée prints.

I will use the Canon Powershot A40 camera to illustrate this point. The button marked Menu on the body of the camera displays the resolution and compression settings. Select M2=1024x768, M1=1600x1200 or L=2272x1704 to produce giclée prints. The larger (L) file size is best for large format prints.

The Canon Powershot stores photos in a format that is dowloaded in JPEG file format. Digital SLR cameras also offer RAW or RAW+JPEG file formats that are best for producing high resolution prints.

In addition to resolution, the Powershot A40 offers three Compression settings: superfine, fine and normal. The size of the image saved with superfine compression is larger, so this is the best format for producing high resolution photos.

Summary. Select the highest resolution and least amount of compression to optimize your digital photographs for giclée prints.

2. Photo Exposure. There are four digital camera settings that bracket exposure. AUTO exposure automatically sets all four. Digital SLR cameras and some digital snapshot cameras also allow you to set them manually to refine photo capture:

ISO. In the pre-digital camera age this was known as film speed. To capture subjects in low light levels, increase your camera's ISO setting. For instance, use ISO 64 for direct sunlight, ISO 100-200 for moderate to cloudy daylight, and ISO 400 or above for interior photos. Note that ISO can only be set when AUTO [P] exposure is not selected on most digital cameras that offer manual setting features.

APERTURE. Or, the size of the lens opening when the digital scan is taken. The SMALLER the f-stop NUMBER the LARGER the lens OPENING. Yes, a 4.5 aperture f-stop allows more light to reach the image sensor than an 11 apeture f-stop setting. Outdoor photos in full sunlight usually require an aperture setting of 8 or above, and interior ones without a flash (and enough indoor light) require 4.5.

SCANNER SPEED. Yes, that's scanner not shutter speed. Since digital cameras use digital image processors rather than film to capture images, the amount of time light is exposed to the camera's digital processor is the same as the shutter speed setting on film cameras. Higher speeds = less exposure time, thus less light will reach the digital processor.

WHITE BALANCE. Typically set at AUTO, some digital cameras also allow you adjust the hue of white to compensate for different lighting conditions.

AUTOMATIC [AUTO]. Most digital cameras have an automatic setting that optimizes light exposure so ISO, aperture, scanner speed and white balance are optimized based on the camera's built in light exposure meter reading.

Exposure Setting Summary: Settings with accompanying low and bright light conditions:

High ISO setting = low light
High Scanner Speed = bright light
High Apeture (f-stop) = bright light

So, what is "good" exposure? Good exposure is a photograph that exploits the entire range of white to black and the color spectrum without loosing detail in the very dark or light areas of the print. Most high end digital cameras and digital photo processing software use the histogram to illustrate that range. Here is one example of a bad exposure with it's original histogram, and how the photo looked after correcting the exposure with Adobe Photoshop.

THIS EXPOSURE is washed out. Note the dark end of the histogram (the height of lines to the left) is weak as well as the light end (absence of lines to the right). There is no detail in the dark, nor the light areas of this photograph.

HISTOGRAM =>

The same photograph in which the range is adjusted to increase dark and light areas during the digital photo processing phase of producing the giclée print.

While many deficiencies in the amount of light and scanning speed can be corrected by the digital proofing process, it is far better to start with a photograph whose ISO, aperture, speed and white balance have achieved consistent exposure and a wide range of gradients from light to dark across the color spectrum, similar to this photo taken at sunset when the sun's light is fading.

HISTOGRAM =>


IONA Print Studio uses Epson Stylus Pro 7890 printers with archival Ultrachrome Vivid Magenta K3 Inks and archive quality fine art papers and canvas to produce prints that are colorfast for 70-100 years when properly framed and stored.