470207

Meade ETX-90AT Manual

41
Zoom out
Zoom in
Previous page
1/60
Next page
41
Photography through a long lens, such as the ETX, requires special technique for
good results. The photographer should expect to use several rolls 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 standard tripod or the optional table tripod ( see OPTIONAL ACCESSORIES,
page 43) as a platform for the telescope. At effective focal lengths of 1250mm to
1450mm (ETX-90AT), 1640mm to 1830mm (ETX-105AT) or 1900mm to 2310mm
(ETX–125AT), 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 with your camera. 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
EQUATORIAL (POLAR) ALIGNMENT, page 51).
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.
Photography with a Digital Camera
Although digital cameras still cannot match the quality of images provided by
traditional 35mm cameras, they provide some significant advantages to the casual
astrophotographer: You do not have to develop the images (instant images), lower
costs, computer and internet readiness. And because unwanted photos are easily
discarded, they provide the freedom to experiment.
Digital cameras present some problems for the astrophotographer: Many models
have lenses that cannot be removed, difficulties in attaching to a telescope, possible
vignetting, lack manual focusing and shorter exposure times.
Shorter exposure times is one of the biggest drawback. Long exposures with digital
cameras introduce undesirable noise and artifacts into a digital image. This limits the
range of astro images to the Moon, planets and bright stars.
Some tips for better photos:
• If you cannot remove the lens to your camera, look for a commercially available
digital t-adapter. New solutions for attaching a digital camera to a telescope are
becoming available as time goes by.
… 41 …


Need help? Post your question in this forum.

Forumrules


Report abuse

Libble takes abuse of its services very seriously. We're committed to dealing with such abuse according to the laws in your country of residence. When you submit a report, we'll investigate it and take the appropriate action. We'll get back to you only if we require additional details or have more information to share.

Product:

For example, Anti-Semitic content, racist content, or material that could result in a violent physical act.

For example, a credit card number, a personal identification number, or an unlisted home address. Note that email addresses and full names are not considered private information.

Forumrules

To achieve meaningful questions, we apply the following rules:

Register

Register getting emails for Meade ETX-90AT at:


You will receive an email to register for one or both of the options.


Get your user manual by e-mail

Enter your email address to receive the manual of Meade ETX-90AT in the language / languages: English as an attachment in your email.

The manual is 4,08 mb in size.

 

You will receive the manual in your email within minutes. If you have not received an email, then probably have entered the wrong email address or your mailbox is too full. In addition, it may be that your ISP may have a maximum size for emails to receive.

The manual is sent by email. Check your email

If you have not received an email with the manual within fifteen minutes, it may be that you have a entered a wrong email address or that your ISP has set a maximum size to receive email that is smaller than the size of the manual.

The email address you have provided is not correct.

Please check the email address and correct it.

Your question is posted on this page

Would you like to receive an email when new answers and questions are posted? Please enter your email address.



Info