Explains the purpose of stacking teleconverters and how to calculating focal length, aperture, and aperture diameter.

Using auto teleconverters and auto extension tubes with manual lenses. A few years ago, my friend was working for a telescope company.

i had just tried this evening using my new 1.4 teleconverter with EOS cameras attached to my scope and couldn't get the camera to work except with the ...

The Olympus 1.45x teleconverter is intended for Olympus ZLR camera lines. These SLR cameras have zoom lens permanently attached to their bodies.

These teleconverters include front and rear lens caps, lens pouch, and instruction manual. The C-210 model even comes with a built-in lens hood that snaps into ...

The auto-focus mechanism on this lens is based on Canon's micro motor. It is noisy and doesn't sound very smooth. In low-light and low-contract situation, it ...

For most folks, the lens will be used in auto-focus mode. The ultrasonic motor (USM) on this lens is fast and accurate. In bright light, it locks on the subject ...

Oct 4, 1999 · With a perfect converter 2x you increase by 4 the surface of smallest blurring so if your lens is only quite good, you will just increase the ...

The quiet USM focus keeps the atmosphere of a quiet conversation intact. The fast focus operation of the USM also reduces hunting in low light, allowing me to ...

Are you willing to sacrifice the ability to auto-focus (AF). If you are not willing to sacrifice AF, your only choice is to buy a higher-end lens. You see, with ...