Members of the Forum often discuss coin photography, and many a lively discussion has taken place over the years. Below is an excellent post made by Modorator Jason Cuvelier on photography basics and that thread can be found HERE for further information. Using the search function for photography on the Forum will bring up THIS result.
To effectively take pictures, it is suggested that one have a rudimentary understanding of photography.
Photography: capturing a specified amount of focused light, for a set period of time, onto a light sensitive material (the film plane.) The mechanics can be simple or complex…
Light hits a given instance, reflects off, and then travels toward a small opening on to your camera. A cone shape is created that become smaller as it directs toward you. There is a lens or an opening that helps to focus the light where it will then at a given distance flip and invert itself and spread back out into a new cone toward the film plane (a light sensor or film.) The size of the opening is called the aperture and it works with the lens to help establish the amount of light, the focus, and the depth of field. Additionally, the opening will also have a correlation with the next step, time required (or exposure), created by the release of a barrier exposing the light to a given light sensitive material (the shutter speed.)
Most modern cameras take all of these factors, along with many others, and focus the lens through triangulation. The camera automatically calculates for the user the correct aperture (f-stop); shutter speed (time); degree of light sensitivity of the sensor or film; adjustment for white balance (and the type of light encountered); and if required the amount of light and time a flash will illuminate the scene – all in a matter of micro seconds. Some cameras have image stabilization software to help counter-balance camera shake.
The user still must be aware of the limitations of the scene they intend to shoot and the equipment they are using. Cameras capture light and record it – nothing else. If there is not sufficient light the camera cannot do its job. The less light available, the longer the exposure, the harder it is to hand hold during the picture taking process and or capture an object that is moving.
Depth of field is the distance between two points in your field of view where and object remains in focus. Depending upon certain variables this can be extremely small, let’s say a millimeter, and infinite. It will mostly depend on the lens and the distance between the scene and the camera, but also depends on a correlation between the amount of light available that is directed through the aperture.
Film or sensor sensitivity is also a factor. Black and white film captures the greatest spectral range followed by color film, and finally slide film and digital sensors. This means the given range of hues; saturation; and lightness are limited to a set amount per picture. With digital photography, when one goes above or below the range you are working within, the camera subscribes values of 0 (black) or 255 (white) to those areas. That is one of the reasons why it is recommended to diffuse or bounce electronic flash (or other lights) as opposed to working with that bright light directly because the range can be too great for the sensor to handle.
Once you captured light onto your camera, then you enter post-production which can be simple or complex. It might be you hand the film to a photo-technician and wait an hour for prints. It could be downloading digital information onto a computer and allowing software to automatically configure everything and hope for the best. Or possibly the user may manually edit, crop, reconfigure, touch up etc. the exposed film or digital images. Experienced digital photographers in general use Photoshop to edit their pictures (version 7.0 or higher.) This software, which can be expensive, allows for almost complete control over the media. The amount of alteration can be simple like cropping and output size or more complex like advanced color correction or dealing with selections and manipulations. There is of course a finite ability to manipulate any given image and it greatly depends on the amount of information in the original image captured. Photoshop is fantastic but can be overwhelming and take years to learn. There are simpler and cheaper photo editing programs that can be perfectly sufficient.
Shooting macro-photography depends on your equipment and your knowledge of the given situation to obtain satisfactory results. The principal of macro-photography differs from other photographic situations in that the scene is either the same size or smaller than the film plane. Most older cameras were not designed to shoot objects close up and required special equipment as a result. Fortunately modern cameras (especially compact point & shoot digital cameras) have been constructed differently and have smaller sensors that essentially make the lenses appear longer and achieve a degree of magnification impossible with film. They have also been given software (a brain essentially) that helps the camera reconfigure itself to deal with these particular situations. The variables are the same though. The amount of light required, the limited depth of field (which is very shallow), pinpoint focusing, distance between the lens and the object (which can nearly be touching), the amount of time needed to capture the scene and the sensitivity of the sensor or film.
If the camera is capable of shooting an object that nearly touches the lens, then the issue of light quantity becomes a problem logistically because the camera is literally inhibiting the illumination of the scene. This can be corrected by either shooting with enough distance to allow at least some light to come through or by introducing bright light. One can use intense box lights or strobes, or maybe even the flash on the camera but the light will likely need to be diffused for a more even appearance. Another logistical concern when the camera is that close to your scene is to consider the angle you are shooting with that of the picture plane. Anything that moves away from being parallel can lead part of your intended scene to drift out of the depth of field. Many photographers use this as a device to control what they want the intended viewer to see. (Think commercial photography.) An object or person is in focus and everything else blurs out so you focus on a particular area first and notice whatever product they are offering.
It should be remembered that with digital photography the image captured can be easily resized up or down, cropped or reworked with ease. That means a larger image can be taken to allow for greater depth of field and more light, then manipulated and cropped later to the particular detail(s) wanted.
Extreme close up photography works best with the use of a monocular or binocular scope that become an intermediary between the object or scene and the camera capturing the image.
The shutter speed obviously determines the speed that the shutter stays open during exposure. (If your camera tells you) speeds below (approximately) 1/30 of a second become difficult to hand hold without obtaining a blurry image. A tripod or monopod is suggested.
The lens opening is called the aperture and its various sized openings that allows light to come through are called (f-stops.) The general rule is that the higher the number (like f22), the smaller the opening, which means less light, an increased the depth of field but requires a longer exposure. Inversely, the lower the number (like 2.8), the larger the opening, which creates a diminished depth of field, allows more light and faster exposures. Point & shoot digitals (sometimes) allow for control of the aperture and shutter speeds. Images with shallow depth of field for effect were shot “wide open” as are action shots of athletes caught in motion. If you can shoot a coin at a higher f-stop, with a timer and a tripod, this can give you a little extra depth of field.
ISO numbers, if changeable on your camera, mimic film ISO (formerly called ASA) numbers. The higher the number (like 1600) the more light sensitive the sensor becomes but come at a cost of increased contrast and loss of detail through pixelation. Lower numbers oppositely (like 100) are less light sensitive and have no negative impact on image clarity.
And last but not least, experiment and have fun!
My setup:
The first two images attached were shot with a Canon PowerShot SD300 on macro mode. This is an older camera with only 4MP, the macro setting could be better and focus is tricky and irritating. Lighting was from a 250 watt soft box lamp (the light costs more than the camera.) Flash has been experimented with; using a diffuser or bounce, but a stable light source has been the best thus far. Shots have been either hand held or with one of many tripods lying around the studio.
The close-up shots were taken with a Leica c-lux camera attached to a mono-pod and pressed up to one lens of a binocular scope with a large viewing area on either a 20X, 30X, 40X or 60X setting and subsequently manipulated with Photoshop CS3. The Leica works best with one set of scope lens (10x wide field) while the Canon works best with the other a (20x.) Lighting was a balance between a variable halogen on the scope and a mini-fluorescent light that rotated around the scope and is typically hand held to illuminate key details. The lights are already diffused (to a degree) and are low power and have not needed to be diffused any further. The primary post-production manipulations done were: color correction (making global RGB curve adjustments – both contrast and hue); cropping and resizing; and some touch ups using various tools.
In some instances, glare from a slab, the bottom of the scope or a flip has bounced back up to the scope. This has been alleviated by using black paper around the base of the scope’s viewing area and covering anything white or reflective while viewing or photographing.
Hopefully this information can be used a spring board for a better understanding of photography and macro-photography. It was written by an artist and photographer who has been serious about photography for about five years, used Photoshop for ten years and started shooting coins a few months ago.
Jason Cuvelier