Loupes and Lightboxes
For previewing black and white, color negative or slide film, there is nothing more desirable than being able to examine images under a high-quality loupe on a precisely color-controlled light box. In this way, a photographer can determine which of a series of images is the best or sharpest or which contains subtleties that the others lack. It also becomes easier to judge color, contrast and overall impressions.
A light box can range from an inexpensive $10 plastic box with an incandescent bulb to a wall-mountable, high-priced stainless steel unit with balanced 5000K (Kelvin) illumination. Light boxes serve multiple uses by many different disciplines from photographers and editors to doctors, artists and government agencies or stamp and coin dealers. The range of choices in light boxes is as varied as the different types of cameras available on the market. Size, construction, power supplies and color temperature are only some of the variables to consider when buying a light box. It all comes down to how demanding you choose to be in critically evaluating your images. For simple, rapid-editing purposes, it may not be necessary to purchase a high-end box. However, when critical demands are required and a higher degree of exactitude is necessary, then the buyer should consider making an investment in a light box with more professional features. Color temperature, durability, and other features such as ease of lamp change, carrying facility and storage possibilities should all be considered when making a purchase.
As a general rule, with a light box, you tend to get what you pay for. The less expensive ones may not posses the evenness of illumination along the viewing surface while the more expensive ones remain equally bright edge-to-edge. Some are thinner than others making portability more practical and desirable. Some have carry handles, some don't, while others are either supplied with their own slipcase or are designed to fit inside briefcases. Still others are meant to be wall-mounted much like traditional "shadow boxes" that doctors use to look at X-rays.
Be careful! Light boxes generate white light that is poison to printing paper! One approach you might consider is building a light box into your countertop. In that way it will be flush with your working surface and out of the way.
A loupe is the item you look through to critically examine your image on the light box. It is normally held close to the eye and rested against the image while on the light box. As is the case with light boxes, there are many different styles of loupes to choose from with a wide variety of loupes to suit every film format. For example, for a 35mm frame, a 4x loupe is generally recommended for normal use. However, an 8x loupe for the same image will yield a more magnified image and allow closer inspection for sharpness and detail. Loupes can also be of "zoom" type. These loupes function like traditional zoom lenses on cameras. The viewer can regulate the viewing area to accommodate the area of the image he/ she needs to inspect.
Most good loupes will come with two "skirts" - A clear skirt for examining contact sheets or prints and an opaque skirt for examining slides and negatives when using a light box. The clear skirt allows ambient light to penetrate through its side for illuminating photos. The opaque skirt blocks any extraneous sidelight and only allows the rear lit illumination from the light box to pass through to the eyepiece. Some loupes come with separate interchangeable skirts while others come with two attached, interchangeable sliding skirts.
You will also find loupes made from inexpensive plastic while others are constructed from higher quality metal.
For the amateur or professional photographer seeking to improve his/her craft, a light box and loupe are strongly recommended equipment for the home or studio.