Beginner
tips for making Astrophotography
IF YOU HAVE A DIGITAL CAMERA AND WANT TO TRY YOUR
HAND AT ASTROPHOTOGRAPHY, BUT DON'T REALLY KNOW WHERE TO START, YOU'VE COME TO
THE RIGHT PLACE!
I'll try to give you a little bit of
basic information here on these Quick Start web pages to get you started.
You'll find more on the rest of this web site, and in my book if you really want
to learn all about it.
1. What you need:
You
need a camera that has manual exposure mode. Most SRL camera come with a
feature called Bulb which does exactly that.
You
will also need a remote control or a shutter release cable in order to minimize
shaking the camera when taking the pictures.
You will definitely need a tripod.
Other
helpful equipment
- Shutter
release cable isn’t absolutely
necessary but highly recommended. You can by cheap third-party ones on
ebay instead of paying for a genuine one.
- Anti-fog
cloth can help with
condensation that builds up on your lens under certain atmospheric
conditions at night time. If your lens keeps fogging up this might help.
- Red
flashlight to see what you are doing
out in the dark. Using a regular flash light will harm your night vision
but red light won’t.
- A
sky tracking mount to take exposures longer
than 30 seconds or so. This requires an extra investment so I recommend
trying other methods first. I will talk about trackers later.
- A
comfortable chair (you will be waiting a
lot) and extra warm clothes if its winter time.
- Binoculars to
enjoy the view while pictures are being taken or to maybe pick out your
next target.
There
are various types of astrophotography options are there
- Deep Space – Images which are taken
with use of a telescope of objects beyond our own solar system. These are
those stunning images you see of distant galaxies and nebulae, and this is
the most technical and hardest form of astrophotography.
- Solar System – These are images of the
planets, moons and the sun of our own solar system. Again the images are
mostly photographed through telescopes, but a super telephoto lens on a
DSLR cameras can also give you a good result.
- Wide Field
Astrophotography –
This is astrophotography that is taken with a DSLR camera and lens with a
wide field of view, like the wide-angled lens. These are the images you
see that include a starry sky or star trails above a landscape. This is
the most accessible form of astrophotography, and are the kind I practice
and will be teaching you about.
- Time-Lapse Astrophotography – This is just an extension
on Wide Field Astrophotography. The only difference is you take lots of
exposures over time and then combine the frames to make a time-lapse
video. The same technique can be used to make a star trail image.
Tips
for Beginner Astrophotography
Start
out simple – Learn how to focus on a star and how to determine the correct
exposure by using the histogram. Here are some subjects you can shoot with just
a camera on a tripod:
- Twilight scenes
with the crescent Moon with Earthshine and bright planets nearby like
Venus or Jupiter
- Asterisms like
the Big and Little Dipper, and constellations like Cassiopeia and Orion
- Satellite passes
such as those by the International Space Station, and Iridium satellite
flares
- Circumpolar star
trails
- Meteors and
meteor showers
- The phases of
the Moon
- Aurora
ISO Settings for Astrophotography
A major
component of beginner astrophotography is selecting the proper ISO setting.
The ISO setting controls how sensitive your digital camera is to light.
Selecting a higher ISO number will increase the sensitivity to light on your
camera, and record more detail in a low-light light situation. The catch is, it
will also produce more noise. Noise looks like little colored grains in
your photo. The trick is to find the right balance between detail and
noise. A modest amount of noise can be removed during post-processing in Adobe
Photoshop, a heavy amount can make your photo a real mess. I suggest shooting
in the 1600-3200 ISO range to limit noise, yet pull out some serious
sky-detail.
Long Exposure Photography
Night
sky photography is considered “long-exposure” photography, but how do you know
how long to expose the image? It depends on a number of factors, and one of
them is whether or not you own a shutter release cable. If you don’t, your
maximum exposure length will be 30 seconds. A shutter release cable will
allow you to set your camera exposure length on “bulb” mode, and take an
exposure as long as you want. I’ve had success with inexpensive shutter
release cables I found on eBay. In my opinion, without a tracking mount, an
exposure of about 30 seconds is as long as I would go anyway. Any longer
will start producing star-trails.
Achieving Sharp Focus
The
next thing you will want to make sure of is that you camera lens is set to
manual focus, and set to infinity. You will do this by switching your lens to
the “M”, and adjusting the barrel to the infinity symbol. Once you have
set your lens to this spot, take a few test shots to check and see if your
stars are in focus. They will show up as tiny pin-points of light when a sharp
focus is achieved. If your camera has a live-view mode like the 70D, you can
zoom in with the LCD screen on the back, and focus on the moon or a distant
object. Adjust the focus ring until the object is sharp, and then un-zoom, and
return the camera back to your intended target position in the night sky.
Give a Shoot!
Now, if the moon is up,
it can be VERY bright, especially if it is more than half-illuminated. If
you want lots of stars and even bright galaxies or nebulae to show up in your
photo, you will have to take your shots during the nights leading up to, and
after the New Moon when a thin crescent moon sets in the early evening or rises
at dawn. A great idea for beginner astrophotographers is to aim for a
pleasing landscape shot of a known constellation. If the moon is out, the
moonlight can actually help light up the scenery below to create an interesting
image.
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