Meade ETX-105EC, ETX-125EC instruction manual Example of a format 1 photo, Few Tips on Photography

Fig. 18: Example of photography through the ETX using the

#64 T-Adapter: (1) Short section of #64 T-Adapter;

(2) Extension section of #64 T-Adapter; (3) Knurled attachment ring; (4) T-mount; (5) Flip-mirror control in “down” position; (6) 35mm camera body; (7) Format 1.

Format 2 utilizes both sections of the #64 T-Adapter threaded together to form a rigid unit. In this configuration there is no field vignetting: images are illuminated to the edges of a standard 35mm frame (see Fig. 20).

To frame an object in the viewfinder of the 35mm camera body, slightly loosen the knurled attachment ring (3, Fig. 18), which threads the #64 T- Adapter to the telescope’s photo port; rotate the camera body to achieve proper framing of the object; then re- tighten the knurled ring.

2 1

3

6 4 5

7

Fig. 19: Example of a format 1 photo.

Fig. 20: Example of a format 2 photo.

Photography through a long lens, such as the ETX, requires special technique for good results. The photographer should expect to use a roll or two of film in acquiring this technique. Long-

lens photography has its own rewards, however, which short-focus lenses cannot duplicate.

A Few Tips on Photography

1.Use the optional table tripod specific to your model of ETX, or the #883 Deluxe Field Tripod as a platform for the telescope. At effective focal lengths of 1250mm to 1450mm (ETX-90EC), 1640mm to 1830mm (ETX-105EC), or 1900mm to 2310mm (ETX–125EC), even small external vibrations can easily ruin an otherwise good photo.

CAUTION: With the #64 T-Adapter and a camera body mounted to the ETX photo port, the telescope can be rotated vertically only 45°. Moving past this point may damage the telescope and camera.

2.Use a cable-operated shutter release. Touching the camera body to operate the shutter will almost certainly introduce undesirable vibrations.

3.Focus the image with extreme care. While observing the subject through the camera’s reflex viewfinder, turn the ETX's focus knob 8,( Fig. 1) to achieve the sharpest possible focus. Note that some 35mm cameras may have an optional focusing screen (available from the manufacturer) for use with a long telephoto lens. This screen provides a brighter and clearer image to focus and is highly recommended.

4.Correct shutter speeds vary widely, depending on lighting conditions and film used. Trial-and-error is the best way to determine proper shutter speed in any given application.

Note: The camera used with an ETX model may have an exposure meter that is still active when the standard lens is removed and the body is connected to the telescope with the T-mount. If used for terrestrial photography, the camera meter should be acceptable. If used for astrophotography, the meter probably will not provide good results since camera meters are not made to compensate for a dark sky.

5.Terrestrial photography through an ETX model is sensitive to heat waves rising from the Earth’s surface. Long distance photography is best accomplished in the early morning hours before the earth has had time to build up heat.

6.Photography of the Moon and planets through an ETX model can be especially gratifying, but points 1 through 4 should be particularly noted in this case. Lunar or planetary photography requires that the telescope be polar aligned (see POLAR ALIGNMENT PROCEDURE, page 16), and that the telescope’s motor drive be in operation (see APPENDIX A, page 26).

Note: Long-exposure photography of deep-sky objects is not practical with an ETX model, since this type of photography requires special electronic and optical guiding devices not available for this telescope.

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