JCPenney Auto 2x Tele-converter Pentax K

The JCPenney Auto 2x Tele-converter for Pentax K is another teleconverter designed to double the focal length of compatible lenses. This model was marketed under the JCPenney brand, which offered a variety of photography equipment.

Key Features:

1. Compatibility: Specifically made for Pentax K mount lenses and cameras.
2. Magnification: Provides a 2x magnification, effectively doubling the focal length. For instance, an 85mm lens will act like a 170mm lens when used with this teleconverter.
3. Automatic Diaphragm Control: Maintains automatic diaphragm functionality, which allows for the continued use of automatic exposure modes.

Usage Considerations:

1. Image Quality: As with most teleconverters, there is typically a reduction in image quality. This includes potential loss of sharpness and contrast. The overall impact depends on the quality of the teleconverter and the primary lens.
2. Aperture Reduction: The teleconverter reduces the maximum aperture by two stops. For example, a lens with an aperture of f/2.8 will become f/5.6.
3. Autofocus Performance: Autofocus may become slower or less accurate, especially in low-light conditions or when using lenses with smaller maximum apertures.