Download How To Guide: Astrophotography with a DSLR

How To Guide: Astrophotography with a
DSLR
Photography Gear, Photography Gear Tips & Tricks Add comments
Jul
112012
Getting started in Astrophotography is
easier than you think but mastering it will take a life time. This is a guide for
beginners or people with a small amount of experience. I’ll be focusing on
taking pictures with nothing but DSLR cameras and regular lenses. No
telescope required! The only other piece of equipment you will need is a
tripod. If you have another type of digital camera with a “manual” setting you
can still follow along though some of the options I talk about may not be
available to you. Later on I will go into some other pieces of gear you can buy
that will further enhance your ability to take pictures. Finally we will talk about
how to process your images in Photoshop as most of the time the image
straight from the camera is a bit underwhelming. All the pictures featured in
the article were taken by me with a DSLR (either Nikon D300 or Nikon D700).
Milky Way – Nikon D700, 105mm f/3.5, 8x2min,
ISO 3200
Choosing A Camera
Did you know?
Some DSLRs can be modified specifically for
Astrophotography use. While DSLRs are fine
for photographing stars, galaxies, and
reflection nebula their weak point is emission
nebula because they have an built-in filter to
block out certain wavelengths of light. By
removing this filter or replacing it with clear
glass you can improve the sensitivity for
hydrogen-alpha light. One company that will
do this to your camera, or sell you a premodded one is Hutech. Canon has even
released a DSLR specifically for this purpose
known as the Canon EOS 60Da. The benefit
of that is you still get a full manufacturers
warranty.
The downside? This mucks up the color
balance of regular daytime shots, so it is not
the best option unless you want to use that
DSLR solely for Astrophotography.
Any Digital SLR camera should be
enough to get you started. If you are
looking for a specific camera to buy
for this purpose, Canon’s are the
most popular for astrophotography
but Nikon’s also do fine. The most
important reasons for using a DSLR
are the large sensor (for better signal
to noise ratio), the ability to keep the
shutter open as long as you want and
the ability to shoot RAW files. This makes full-frame DSLR’s even better
because their sensor is larger than regular DSLR cameras. The last basic
piece of equipment you need is 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.
Nikon D700, 24mm f/3.5, 120 seconds, ISO 1600 single exposure
Choosing A Location
Some types of Astrophotography are doable in the middle of the city but that
tends to be limited to lunar or planetary photography. Planetary photography
requires a telescope but if you have a telephoto lens of at least 300mm or so
you can get some nice shots of the moon. Photographing deep sky objects or
getting a lot of stars in your image is not very doable in the middle of a city.
The good news is just driving for 15 minutes outside of city limits can really
improve the sky quality.
I want to shoot…
Location
The Moon
All you need is a clear sky! This can be done right in the
middle of a city.
Night-time
landscapes
(Starscapes)
Starscapes are shots where the landscape is mostly lit by the
moon (or stars at exceptionally dark locations) and you will
need moderately dark skies for this. Think Suburbs or darker.
Wide-field shots or
Constellations
You can get away with doing some of the brighter
constellations inside a medium size city as long as you are
sheltered from city lights by trees or buildings but outside the
city will be best.
Star Trails
About the same as Constellations, but as with any Astrophoto
the darker the sky the better. If you want to do very long single
exposures you need a true dark sky site, but if you plan on
stacking many shorter exposures you have a lot more
flexibility.
The Milky Way
For this it is ideal to be at least 30 miles/50km away from any
city or town. You can get away with being closer to the city if
the milky way is in the sky opposite the nearest city. For the
absolute best milky way images you need to be many hours
away from any cities.
Galaxies and DeepSky objects
The requirements are the similar to Milky Way shots; rural
skies or better. Some objects will photography decently even in
suburban skies. Some of the bigger objects like Andromeda
Galaxy and Orion Nebula can be done with a telephoto lens
but you will still need a tracker of some kind to move your
camera with the motion of the sky.
Light Pollution
Light pollution is caused by stray man-made light that is aimed at the sky. The
main problem for astronomers is it washes out the sky and reduces the
amount of stars and deep-sky objects you can see and/or photograph. Aside
from the aesthetic problem of the nasty orange haze in the sky instead of
stars, light pollution is an incredible waste of energy. Why do we need to light
up the sky? If all the light from street lights and outdoor lights was aimed at
the ground with proper shades above them to reflect ALL of the light to the
ground, you would be able to use lower power lights. Lighting up the sky is
akin to leaving all your windows and doors open while you leave your furnace
on in the winter. A complete and utter waste of energy. You can find more
information at the International Dark Sky Association.
If you live in the USA or parts of Canada you can see how the light pollution is
where you live by going to the Dark Sky Finder site. You can also get a good
idea of where you would have to go to get dark skies. For other countries if
you Google your country name along with “light pollution map” you should
hopefully have some luck in finding one.
Beginner Shots
In this part we are going to cover all types of shots that can be taken with your
DSLR without a tracking mount – moon shots, starscapes & widefield shots,
star trails and milky way wide shots.
Guide Navigation
Introduction & The Basics | Beginner Shots | Advanced Shots | Photoshop Processing
Lunar Eclipse & Saturn – Nikon D300, 240mm, f/6.3, 0.3 seconds, ISO 1600 single exposure
Moon Shots
The above shot of the February 20th, 2008 lunar eclipse was taken just with a
70-300mm lens and a tripod – nothing fancy. That brightest point of light on
the left side is actually Saturn. A view like this wouldn’t have been possible
with a telescope. While close ups of the moon are great you can get
interesting shots like this with just a telephoto lens.
Focusing can be tough in Astrophotography but moon shots are the exception.
My suggestion is to use your camera to autofocus on the moon and then set it
to manual focus and be careful not to adjust the focus. Even though the moon
is bright and you can use a fast shutter speed you still need to minimize
camera vibrations. If you don’t have a remote shutter cable to trip you should
use the self timer mode on your camera to take shots. Something like 3 or 5
seconds is enough for vibrations to dissipate. You will want to use manual
exposure mode for the moon as auto exposure will overexpose it usually.
Here are some recommended settings to try:
Full moon: f/8, 1/640, ISO 200
Half-moon: f/8, 1/500, ISO 400
The above are only starting points. Exposure time will change with the moon’s
position in the sky and other factors. You want it to be bright but be careful not
to overexpose the brightest edge. Below are some ideas for other types of
shots you can take of the moon (click to enlarge). The first one is showing off
the “earthshine” on the moon’s surface. The overexposed part is what you are
normally seeing the the dim part is normally cloaked in shadow but with a long
exposure you can see the shadowed section of the moon dimly lit by the
earth’s reflected light. The other one is a stylized picture of the moon in some
clouds.
Starscapes and Wide-field shots
Starscape over a camp fire – Nikon D700, 24mm, f/4, 60 seconds, ISO 1600 single exposure
Starscapes are probably my favorite type of shot to take. In the above shot I
was looking forward to taking some milky way shots but the clouds rolled in as
you can see. While they would have ruined the shots I planned on taking they
arguably enhanced this one. What I just said is tantamount to blasphemy
though. Clouds are the arch-nemesis of any astronomer!
Focus:
The first thing you need to do is focus on the stars. There are many ways to
do this but you may struggle your first few times – don’t get discouraged. If
you have an older style lens (the ones that usually have an f-stop ring right on
the lens) those lenses typically have a hard infinity focus stop so they are the
easiest; focus to infinity and you are done. This is probably why my 2 favorite
astrophotography lenses are my 24mm f2.8 Nikon prime and 50mm f1.8 Nikon
prime. More modern DSLR lenses usually don’t have a hard infinity focus
point though so you may need to do some trial and error.
If your lens doesn’t have a hard infinity focus point:
See if your camera will autofocus on a bright star (or the moon if its out). If it
does, great! Once its autofocused switch the focus to manual and be careful
not to adjust it. If your camera fails to autofocus, put it in live-view mode on
your tripod and point it at the brightest star (or moon if available). See if you
can focus on the live view mode. If not, manual focus as best as you can in
your viewfinder then take a test shot. To make it quick, use a high ISO like
3200 and take a 5 or 10 second picture and check the stars. Keep fine tuning
your focus til the stars are solid points of light. They are out of focus if the
center is dimmer than the outside.
Exposure:
The first thing you want to do is stop your lens down at least 1 stop to improve
the quality of stars and reduce vignetting. If the max aperture for your focal
length is say f/3.5, try using something like f/5. If you are in moderately dark
skies (rural, out of the city) try taking a shot with a 30 second shutter speed
and ISO 1600. Most DSLRs max shutter speed is 30 seconds and to go
longer you need to use “BULB” mode. So for longer than 30 seconds you
need a remote shutter cable to keep the shutter open (bulb keeps it open as
long as its pressed – you can’t do this with your hand or your shot would be a
blurry mess). If you have a newer model camera you can probably get away
with ISO 3200 to double your light.
Other settings:
Disable any camera noise reduction settings. You are better off doing your
noise reduction in post. If you don’t want to get too advanced with post
processing, you can leave “long exposure noise reduction” on. What this
setting does is take a second picture but with the mirror down so no light can
hit the sensor. This is called a dark frame. Then the camera automatically
subtracts it from your shot to reduce dark current noise and hot pixels.
Personally I prefer taking my own dark frames and subtracting them myself as
necessary…plus that way I can take multiple dark frames.
Dark Frames?:
It’s a good idea to take these if you had long exposure noise reduction turned
off in your camera… you may need them later in processing. To take a dark
frame, put your lens cap on and take pictures using the same settings you did
with the lens cap off (only ISO and shutter speed is important). The most
crucial thing is to take them in an environment with the same temperature as
your regular pictures since temperature affects the noise. I usually take my
dark frames while I am packing up all my stuff at the end of the night. So if
your shots were 30 seconds, ISO 1600 take a few dark frames at those
settings.
Other Starscape examples (click to enlarge)
Star Trails
Star trails in black and white – Nikon D700, 24mm, f/4, 6x11min exposures stacked (66min), ISO 640
Star trails are one of the most popular types of Astrophotography. It’s hard to
perceive the movement of the sky due to the earth’s rotation unless you are
looking through a high power telescope and then you can watch an object
pass across the field of view in a matter of seconds. The longer your lens, the
longer your star trails. Using a wide angle lens it takes around 20-30 seconds
for trailing to become apparent but with a 300mm lens it happens in less than
5 seconds. There are 2 methods of taking star trails which means you can
take them in virtually any environment except metropolitan.
Getting Ready
You will need to achieve proper focus as described in the above “Starscapes”
section and make sure your camera’s battery is fully charged (bring a spare if
you can). If you are going to use the stacking method things will go easier if
you camera has an intervalometer or you buy a remote shutter cable that can
be programmed to take shots at specific intervals such as the Canon
TC80N3 or Nikon MC-36. There are also cheaper third party models on eBay
that also work for more camera models (Nikon remotes and Canon remotes).
Look for the ones with the little LCD screens.
Regardless of what method you use, you don’t want to leave your lens wide
open. It’s best to stop down at least 2 full stops so you get sharper stars
across the whole image. If you are rocking $2000 glass I suppose you can
ignore my suggestion. If your max aperture for the focal length you chose is
say f/3.5, try shooting somewhere between f/5.6 – f/8.
Single Exposure Method
With this method you just take one extremely long exposure. Anywhere from a
few minutes to hours! There are some strict requirements for being able to do
this method though. The first one is there can’t be any moon in the sky. It will
end up overexposing not only your sky but also any landscape your happen to
have in your shot. The only exception being you can sometimes manage
shots under 30 minutes if you use ISO 100. The second requirement is
extremely dark skies. If you are within ~100 miles of any city or town, forget
about doing that hour long exposure you were thinking about – the light
pollution will wash out the sky and your stars. Cameras can drain battery fast
when they leave the shutter open. It will vary from camera to camera but you
may need to use a power adapter for your camera instead of a battery.
Finally, some cameras will just have a finite amount of times that they can
keep their shutter open (and thus their CCD or CMOS amplified) before “amp
glow” becomes an issue. Amp glow is caused by heat in the camera and
usually starts at the edges of the image and gets worse. If you are taking
pictures in cold temperatures you might avoid it all together.
Picking the right exposure settings can be tricky. If you let in too much light,
your picture will get washed out and overexposed. If you let in too little, fainter
stars may never get a chance to register on the sensor because they have
moved before they were able to expose. In most cases you will want to use
ISO 100 or ISO 200 depending on your f-stop and exposure length. You can
test out how many stars you will get by taking a shorter exposure of say
around 5 minutes. Any trails you see there will be the exact same trails you
see on longer exposures, only they will stretch longer. One setting you can try
first is this: f/5.6, ISO 100, 30 min (1800 sec) shutter speed. By using that as a
baseline you can see if your sky is too bright or too dark, if your landscape is
exposed properly, if there is any amp glow, etc. The single exposure method
requires a lot of trial and error but if done properly results in some very
otherworldly looking images.
Stacking Method
With this method you have a lot more flexibility. You can do this in moderately
light polluted environments and when the moon is out as well. The basic idea
is instead of taking one single 60 minute exposure you would instead take 60
separate 1 minute exposures and stack them to make it look like a single
continuous star trail. You don’t want to have more than a second in between
shots or else the gaps between images will be too large. You can use
exposures with higher ISOs to gather more stars compared to the single
exposure method. It’s quite simple; find the exposure setting you want for your
picture and by taking multiples of that same exposure and stacking them, the
star trails will grow and nothing else in the image will change.
I will discuss this again in the processing section of this guide, but the basic
method to stack in Photoshop is to load up all your frames into separate layers
and set all the layers to the “Lighten” blending mode. Better yet, there is a
fantastic little program called Startrails that does this for you and also lets you
load in dark frames. You can download it here at Startrails.de.
More Star Trails examples (click to enlarge)
Milky Way Widefield Shots
The Milky Way – Nikon D700, 24mm f/3.5, ISO 2000, single exposure
The Milky Way appears as a long cloud arcing across the sky when you view
it with the naked eye, but that “cloud” is actually the combined light of billions
of stars so tightly packed together and so far away that our eyes can’t
distinguish them. With a telephoto lens you can distinguish a lot of them
though and what you are presented with is a wall of stars. The darker regions
in the Milky Way are vast clouds of interstellar dust blocking the light of stars
behind them. The constellation Sagittarius is roughly the center point of the
galaxy and when you look there you are peering to the middle of our galaxy
though most of it is obscured since we are looking at it from the side.
Getting a good Milky Way shot is highly dependent on the light pollution
levels. If you can find your location on a light pollution map (such as the one I
linked to at the bottom of page 1) see what shade of color you are in. If it’s
anything worse than green, forget it. Blue is better and Black is perfect.
The shot you see above was taken on the edge of a green zone, the problem
was there was a small town directly south about 10-15km which is where this
shot is pointing. Had the town been North instead I would have been able to
capture more detail in the Milky Way.
As discussed in the star trails section, you can get away with around 30
seconds before trailing is a problem in a wide shot. In dark locations this is
plenty of time to reveal the structure in the Milky Way, especially with a high
ISO like 1600 or 3200. The best part to photograph is the Sagittarius region
(the bottom part of the above picture) which has lots of detail and lots of small
bright red nebula.
Suggested exposure for your first try: f/4, 30 sec, ISO 1600. Try one at ISO
3200 as well if your camera’s noise doesn’t get out of control at that setting.
The Milky Way should be immediately apparent on your rear LCD when you
preview the picture.
Finally, don’t forget to take a series of dark frames for all the exposure settings
you used.
If you want to take close ups of sections of the Milky Way or photography
other deep sky objects like nebula and galaxies you will need to move onto
the Advanced section of this guide. You will now need something to move
your camera with the motion of the sky.
The Milky Way – Nikon D700, 24mm f/5, ISO 3200, single 1 min exposure
Advanced Shots
In this section we will discuss shots that require the use of a tracking mount.
This will require a bit of financial investment but there are some budgetconscious options like the home-made barn door tracker.
Guide Navigation
Introduction & The Basics | Beginner Shots | Advanced Shots | Photoshop Processing
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Without having a way to track the stars you are limited to star trails and ~30
second exposures. While you have a huge variety of pictures to take with that
restriction (as seen on the previous page) you open up a whole new set of
possibilities if you have an equatorial tracking mount as seen above. There
are 5 main components to a setup like this. The Tripod, the tripod head for
your tracking mount, the tracking mount itself, then a ball head and your
camera.
Picking a Tripod
You are going to want something more than you run-of-the-mill $20 tripod for
this type of work. One suggestion would be the Manfrotto 055XPROB. This is
a popular model and found for sale easily (Amazon, Adorama or eBay are
options).
Picking a tripod head for your mount
The next piece of the chain is the tripod head that your tracking mount will
attach to. There are 3 main types of tripod heads – pan/tilt (usually used for
video), ball-head, and geared head. Any type will work as long as it can
support the combined weight load of your tracking mount, camera and lens
but the best type by far is the geared heads as they make fine tuning your
polar alignment much simpler. With a ball head you will have to hold your
entire apparatus as you align it – definitely possible but probably frustrating.
A popular choice is the Manfrotto 410 Junior Geared Head
(Amazon, Adorama or eBay) which has a large weight capacity and very
smooth and accurate fine tuning. It also has a built-in level which is helpful.
Ball head for your camera
The ball-head goes from your tracking mount to your camera. This is so you
can keep your tracking polar aligned but freely move your camera in all
directions to take different shots.
Any ball head will do as long as it can support the weight of your camera. I
recommend something like the Manfrotto 496RC2 (Amazon, Adorama
or eBay).
Tracking Mount Options
Home-made Barn Door Tracker
With a couple pieces of wood and a few pieces of hardware you can make a
tracking mount that you manually turn yourself (typically at 1RPM). Tracking
won’t be very accurate but if you build it to exact specifications and polar align
decently you can have widefield exposures of around 5 minutes without any
trailing.
I built one following the instructions in this guide here before moving onto
other methods. It is probably too shaky and inaccurate for telephoto shots but
for wide or medium shots it will definitely get the job done. The downside is
you will be manually turning it the whole time which means sometimes for
hours at a time. Here is another guide for making one.
The Vixen Polarie portable tracker
I really love the Vixen Polarie (Amazon, Adorama oreBay). It’s smaller than
your camera body, runs off two AA batteries (2-3 hours of tracking on those)
and is insanely easy to set up. It costs about $400 and that is priced very
competitively compared to other alternatives. They also make a polar
alignment scope for it for precision alignment that costs almost as much as the
Polarie itself but I have had no problems getting good alignment using the
little “polar sight” hole that is on the Polarie itself. I don’t think the scope is a
necessary purchase unless you plan on doing a lot of 300mm+ long exposure
shots.
The Polarie also features lunar and solar tracking modes as well as a special
1/2 speed “starscape” mode where it tracks at half speed to better keep
landscape elements from blurring but at the same time offsetting star trailing
somewhat. It’s a cool compromise that lets you do nice 1 minute starscape
shots instead of the regular 30 seconds while keeping both landscape and
stars in decent focus.
I have now posted a more detailed review of the Polarie here.
The Astrotrac portable tracking mount
The Astrotrac (Amazon or Adorama) was first to the market with an affordable
and portable tracking solution for DSLR users. The Polarie wouldn’t exist
without the success of the Astrotrac. Due to its design the Astrotrac is
technically more accurate at tracking – accurate enough for people to use
telescopes on it. It also holds a lot more weight than the Polarie but the
downside is its less portable and slightly more expensive. It also requires 8
AA’s to operate instead of 2 AA’s and must be rewound after tracking for a
while. It comes standard with a polar scope though at most places you can
buy it and when you factor that in, its only slightly more expensive than a
Polarie + polar scope combo.
It features solar and lunar tracking modes like the Polarie but lacks the half
speed starscape mode. One feature it does have is a tracking port for
autoguiders to further improve tracking accuracy.
Piggy-back on a telescope
If you already own a telescope on an equatorial mount with a motorized
tracker you can simply piggy back your camera onto the telescope (there are
adapters sold for this purpose) or even directly attach your camera to the
telescope. That is called prime focus but I won’t be covering that here. I want
to focus on what can be done with just your camera and regular lenses.
Polar Alignment
North America Nebula – Nikon D700, 105mm, f/2.8, 10x3min (18min total), ISO3200
In order to track the stars you must align your tracking mount to the celestial
pole. Then the mount rotates at the same rate as the sky to keep the stars in
place. For the barndoor tracker you would sight along the hinge and for the
other mounts they have either a scope to use or in the case of the Polarie a
small hole to look through. Alignment is different in the northern and southern
hemispheres.
Northern Hemisphere Alignment
The star Polaris is almost exactly at the northern celestial pole. If you know
how to find “The Big Dipper” then you can find Polaris. Look North and use
this diagram.
Polaris is unmistakable once you first learn to find it.
Southern Hemisphere Alignment
The star closest to the southern celestial pole is Sigma Octantis in the
constellation Octans. It is a dim magnitude 5.5 compared to Polaris at
magnitude 2. There are 2 main methods of finding it.
If you can see both Magellanic clouds, forming an equilateral triangle with the
third point being the celestial pole gives you an easy way to find Sigma
Octantis. You can also use the Southern Cross method as shown in the
diagram to get you close to the pole.
M51 The Whirlpool Galaxy – Nikon D300, 300mm, f/5.6, 6x2min
Stacking, stacking and more stacking
Now that your camera is tracking the stars you can fully take advantage of
exposure stacking. Stacking is when you take a bunch of images of the exact
same thing and then stack them on top of eachother to improve the signal to
noise ratio. This can drastically reduce the amount of noise in your final
picture and all that extra signal will let you stretch the faint details of deep sky
objects much better in post. In addition to regular frames (called light frames)
there are other frames you should be taking to maximize the quality of your
final image.
Light frames
These are your regular pictures. Take as many as you can! Eventually you will
hit diminishing returns for adding more exposures but more never hurts. A
number I often use is 6. There’s nothing special about this number, I just find it
to be a good compromise of quality and the amount of time it takes to capture
it all.
Dark frames
I discussed these in previous parts of the guide but dark frames are identical
to light frames except you put the lens cap on your camera when taking them.
They are then subtracted from your light frames to remove all that unwanted
junk. It is VERY important to take dark frames at the same temperature as
your light frames as temperature has a big effect on noise and hot pixels. Like
light frames you want lots of these to stack. I like to usually get as many dark
frames as I do light frames.
Flat frames
Flat frames are used to remove vignetting, dust spots and other optical system
anomalies. Flat frames should be shot at the same f-stop and focal length as
your Light frames. It’s best to use Aperture priority with the lowest ISO setting
of your camera (usually ISO 100 or 200). The goal is to get an evenly
illuminated frame. If your camera has a histogram you want the peak to be
right in the middle. One way I like to take flat frames is a clear twilight sky
before you can see any stars. Aim the camera away from the sun so there’s
no gradient and its evenly illuminated across the frame. You can also use a
light box, or throw a few white sheets in front of the lens with a bright light
source behind it. It’s good to take a few of these for stacking.
Great, so you have all the frames. They will be useful later on in the
processing section. One tip to remember is to shoot your darks and flats at the
same orientation as your lights (portrait or landscape) – it just makes things
easier when you are processing everything.
The Orion Nebula – Nikon D300, 1000mm, stack of 10x1minute frames
What should I shoot?
Here’s a few targets to get you started. You can use a program
like Stellarium (free) to find these. There are also lots of books,
iPhone/Android/tablet apps and other ways to help you find objects easily.
•
Hyades and Pleiades star clusters
•
Barnard’s Loop and the Orion Nebula
•
Large and Small Magellanic clouds (southern hemisphere only)
•
Andromeda Galaxy (best for 200mm+)
•
North America Nebula
•
The Whirl Pool Galaxy (300mm minimum)
•
Lagoon Nebula and Trifid Nebula
•
Omega Nebula and Eagle Nebula
•
Flaming Star Nebula
•
Horsehead Nebula
4 nebula in one shot – from top to bottom: Eagle Nebula, Omega Nebula, Trifid Nebula, Lagoon
Nebula. Shot at only 70mm!
So hopefully you have some shots to work with now. Let’s move onto the final
part which is processing in Photoshop.
Photoshop Processing
A lot of the techniques I describe here are most likely possible in other image
editing programs but my only real experience is with Photoshop so hopefully it
is easily translatable if you are using something else. I’m going to assume
you have a working knowledge of Photoshop. This includes converting
your raw files and getting them into Photoshop. If you are a complete beginner
you will probably be lost but this isn’t a Photoshop beginner’s guide. I’ll also be
focusing on a few Photoshop plugins that can greatly enhance your
processing capabilities. There are some freeware tools we will be looking at
too for stacking purposes. These will all be done in video format so I apologize
if my monotone voice puts you to sleep.
Guide Navigation
Introduction & The Basics | Beginner Shots | Advanced Shots | Photoshop Processing
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Stacking with DeepSkyStacker
If you have more than just light frames you can use the freeware
programDeepSkyStacker. I explain the basics in the below video. Note you
will probably have to switch it to 720p or 1080p and go fullscreen to be able to
read anything.
Basic Processing
The easiest ways to immediately improve your image are to neutralize the sky
background (basically white balancing) and correctly setting black and white
levels. I also discuss how you can bring out more structure in things like the
milky way or nebulosity. Note you will probably have to switch it to 720p or
1080p and go fullscreen to be able to read anything.
Noise Reduction Plugins
The Photoshop noise reduction plugins discussed in this video are Nik Dfine
2.0 (also available at Adorama), PictureCode Noise Ninja, and Topaz
DeNoise (my favorite one). Either plugin will serve you well and are much
better than the default noise reduction that ships with many image editing
programs. Note you will probably have to switch it to 720p or 1080p and go
fullscreen to be able to read anything.
StarSpikes Pro plugin
This little plugin is a way to add some character to your stars with Diffraction
spikes and glow effects. It’s available from their website. Note you will
probably have to switch it to 720p or 1080p and go fullscreen to be able to
read anything.
Stacking Star Trails
Here is a quick little video to show you how to stack multiple-exposure Star
Trail images using the free Startrails application.
Final Words
I hope you enjoyed this guide and it encouraged you to try your hand at
Astrophotography. Please leave comments with your feedback and let me
know if there’s anything big that I missed, anything I should change or if
there’s more tutorials you want to see.
Links of Interest
These are some links suggested by readers.
Magic Lantern Firmware – Custom firmware for the Canon 5D MKII,
T1i/T2i/T3i or 50d/60d and potentially more. This is a custom firmware that
can add an in camera intervalometer, longer exposures, more shutter speeds,
ISOs, and more.
Canon Hack Development Kit – Allows you to take RAW exposures and have
full manual control with many Canon “point and shoot” cameras. This may
make some of them viable for some forms of Astrophotography.
Another Barn Door Tracker – A third design for the home made barn door
tracker.
Backyard EOS – Camera control software for Canon DSLRs (hook up your
DSLR to a laptop and take pictures from there)
Astronomy for Beginners – Resource for both observing and astrophotography
for beginners.