The Camera Site

The principal idea of the so called system camera is that it could be adapted to numerous jobs with a range of interchangeable components and specialized accessories. Today, even the most moderately advanced 35-mm system camera can take interchangeable lenses, data backs, close-up and photo micrographic attachments, winders, etc.
Perhaps the most popular accessories for the amateur photographers are various filters, converters, adapters and extension tubes. The main advantage of a converter compared to extension ring or tube is that the minimum focusing distance remains the same when a converter is used and unlike with an extension tube you can stil focus to the infinity. Thus, if you have a 100mm lens that focuses down to one meter, it becomes a 200mm lens that focuses down to same distance when attached to a 2X tele - converter. Because of this, you can get better close-up images by using it. Tele-converter is more expensive than tube because it has optics but it is also more versatile.The main drawback of tele-converters and extension tubes is that they cause a loss of lens speed and they also have more or less negative affect to the overall lens performance. Thus, the development of more and more better and effective zoom lenses might abate the demand of this kind of equipment.

Tamron 2x Tele-converter for Minolta MD-mount. (right)
Most major-brand tele-converters produce good results. There is a slight loss of image quality, but not a lot. Some manufacturers offer matched tele-converters, made specifically for use with a particular lens (or a specific focal-length range). These can produce even better photographic results than general-purpose converters.

Nikon TC-14A, 1,4x Tele-converter (right)

Specifications of Nikon TC-14A Teleconverter

Usable lenses: all Nikkor lenses up to 300 mm focal length, with Reflex-Nikkor lenses, and virtually all Zoom Nikkor lenses of up to 100 mm focal length
Lens construction: 5 elements in 5 groups
Focal length: 1.4X increase in focal length of the lens in use
Aperture coupling range: f/1.8 ~ f/32
Effective aperture: f/2.8 ~ f/45

Filters allow added control for the photographer of the images being produced or like clear filters, simply for protection of the front lens. Most of the colored filters are intended for a B&W (black and white) phptograpy only. For example a yellow filter will enhance the contrast between clouds and sky by darkening the latter. Orange and red filters will have a stronger effect. Filters/Wikipedia

Minolta P-Adapter (right)
This adapter converts Minolta MD-mount suitable for Pentax thread lenses.

Gold Line Wide-Converter, hah!

Edixa extension rings (left)

Konica Macro Lens Adapter (right)

Konica Auto Bellows AR

An equipment for duplicating slides or negatives. Parts from left to right, a Konica Silide Copier 2 AR, a Konica Hexanon AR lens, fitted reversed, for better macro results, with a Slide Copier Adapter to the bellows which are carrying out the same work as extension rings except, that bellows can be adjusted continuously, not only in steps. Because of the greater extension, the distance to the subject can be reduced and greater imaging scales can be achieved.
The aperture must be closed manually prior to exposure except if you use the Konica Macro lens, because macro lens should not be be attaced reversed, Auto Ring and Double Cable Release which closes the aperture and releases the shutter simultaneously.