Deep sky astrophotography is photographing objects that lie
out of our solar system. It can be accomplished with either film or digital
cameras, both pose unique problems.
Cold weather is
preferable for either system, but for different reasons. As the temperature
drops, so does the reciprocity that film exhibits when film is exposed for
longer times than it was designed for; also film does not like humid
condition, and becomes less sensitive to light.
Same cold different reasons, imagers, either CCD
or CMOS generate less noise at lower temperatures, but their is certainly a
decrease in battery power as result of the cold.
Digital is so much more efficient than film
in humid condition, but one has to overcome the noise issue. All digital
images are made up of noise and signal. and this noise can be removed either
in the camera or with very special
programs that are designed for this
purpose. Stacking is another way to decrease the noise to signal ratio.
Either film or digital will have its own obstacles to overcome.
I use a 4" inch refractor now for most of my
photographs; It's easier to focus and is very portable. There is not
a lot to maintain with this type of telescope and it cools down very
quickly, so you can shot almost right away, I also use many different camera
lenses.
When shooting film I use 200 Ektachrome,
when shooting digital images its usually a Canon, other camera's will
also work, but I find Canon to be quieter.
I use a GM8 and manually guide using a twin
scope. There is a lot to photograph in the forest and although not
everything I shoot would classify as deep sky, it is well worth
capturing these special images.
