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Method

Prime Focus Method

 

Connecting the camera to the telescope with a suitable adaptor enables the telescope to become a long telephoto lens.

Camera setting of Prime Focus Method and Eyepiece Projection Method

Eyepiece Projection Method

 

An eyepiece placed in the adaptor will project the prime image formed by the telescope objective lens onto the film with the resulting image magnified.

Application

The Moon and Lunar Eclipse

 

Applied Setting of Magnificaion Photography Method

As the brightness of the Moon varies according to its phases, exposure time should be adjusted. During the process of a lunar eclipse, the brightness is diminishing, thus the exposure should be increased accordingly. To record the reddish-orange colour of the eclipse, the exposure should be 10,000 to 100,000 times the exposure for a normal Moon.

 

The Sun and Solar Eclipse

 

Since sunlight is very strong, do not attempt to take photographs of the Sun, partial or annular solar eclipse without using a professional filter. However, during a total solar eclipse, when the Sun is fully blocked by the Moon, you can photograph it with a telephoto lens or even a telescope.

Planets

 

Planets should be highly magnified with the eyepiece projection method before their disks or surfaces could be recorded. Focusing is critical. The vibration of the telescope caused by wind or the turbulence of the atmosphere will affect the sharpness of the image.

As accurate exposure is essential for magnification photography,the effective focal ratio (or effective aperture) of the projection system has to be calculated.

Prime Focus

Effective Focal Ratio
=
Focal Length of Telescope ÷ Diameter of Telescope
 

Eyepiece Projection

Effective Focal Ratio
=
(Focal Length of Telescope ÷ Diameter of Telescope) × (Projection Distance <Distance form Eyepiece to Film> ÷ Focal Length of Eyepiece)

The recommended exposure can be obtained from "Exposure Table for Magnification Photography".


Exposure Table for Magnification Photography (enlarge)