Imaging with a
.Imaging with a 35mm camera is probably the easiest
and cheapest way to get started in Astrophotography. My choice
of camera was easy - I already had an OM1n camera for my general
photographic work, so this was what I used for my astro work.
I was also fortunate, as several features of the OM 1 series camera
help in astrophotography.
1) Ability to change
2) A good range of
quality and also cheap lenses available.
3) Manual focus - so
not as popular so keeping the price down.
4) A mirror lock up
5) Manual operation
without battery needed for Bulb release.
Going through these
in order, the focusing screen in 'normal' operation is usually
too dark for focusing on astronomical therefore the ability to
put an alternative screen in which makes focusing easier is of
A large range of lenses
from an 8mm Fish Eye - through to large telephotos, means different
fields of view can be obtained of a given event.
Manual focus, autofocus
is not needed and if you have it switch to manual to stop the
focusing jumping around.
Mirror lock up facility
allows you to lock the mirror up after focusing, therefore avoiding
shutter vibration. The traditional 'top hat' technique of opening
the shutter and uncovering the OTA after things have settled down
can also be employed on longer exposures.
Having a camera which
does not need a battery to keep the shutter open means that you
can operate for long exposure without your battery draining in
the middle of a photo session.
There are four main
types of photography : Static camera with lens pointed at the
sky with a tripod, without a drive - (can also be driven for better
images, and pin point stars - not trails), prime focus where the
camera is placed at the prime focus of a telescope in place of
an eyepiece, Eyepiece projection where an eyepiece is used to
project an image onto the film plane, and afocal where the camera
lens is pointed down the eyepiece to image through the complete
Various examples of
these applications can be found on the following links.
Camera - Prime Focus - Afocal - Eyepiece
For more details on
Astrophotography I recommend:
Book - Astrophotography for the Amateur
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