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I am a novice and would like to try shooting stars. Any help would be appreciated. Thanks.

brandi
Apprentice

I have limited knowledge and no users guide.  I have a Canon Rebel XT digital -- they don't even list it on the manual guide page.  I guess that means it's old.  Anyway, I would like to try my luck at shooting stars and would appreciate any advice -- in basic terms, please -- that I can get.  Thanks.

5 REPLIES 5

Waddizzle
Legend
Legend

Visit this page.  Type in your camera's model number in the box, to find the support page for your model.

 

https://www.usa.canon.com/internet/portal/us/home/support

 

From the camera support page, you can download manuals, software, and any firmware updates.

 

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Astrophotography.  That is the technical term for what you're asking about.  Try searching for that word in the camera forum, and you should find qutie a number of articles.  A search of the web should turn up lots of stuff, too.  You may also want to find a web site called "Dark Sky Finder", and some digitial planetarium softwrae to navigate your way around the night sky.  I use "Solarium" for Windows.

 

The simplest from of astrophotography involves using an ultra-wide angle lens [under 20mm] to capture an image of the night sky.  The shorter the focal length, all the better.  You also will need a good and sturdy, professional grade tripod, not one made from plastic. 

 

Plastic tripods are really good at doing the shake and break.  They don't sell professional grade tripods at the big blue box stores, so look on line for metal one with a detachable, replaceable head.  Look for one that can support at least several times the combined weight of your camera and your heaviest lens, at least 15 pounds or so.  You can buy a tripod and head as a kit, or buy them separately.  A ball head is the least costly, easiest to use, and the most popular type. 

 

Raising the center column destabilizes it [a tripod], because it raises the effective center of graivity, which reduces the [working] maximum weight load that you can put on the tripod.  For that reason, I prefer using tripods that do not have center columns.  Curiously, they tend to charge more for tripods without center columns, than they do for tripods that have center columns.

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ebiggs1
Legend
Legend

brandi,

The most important thing is something you can't buy but can cost you a lot of money.  What is it?  It is dark skies.  You need to go to an area where there is as little light pollution as you can.  Usually not in a city or town.  Go to the country.

 

I am sure you already realize you need a tripod as exposures will be longer than normal.  For what you are doing almost any decent tripod will be OK.  You may already have a lens that will work.  Did you get a lens with the XT ?  Perhaps a 18-55mil ? The 18mm side will work.  You need to set the XT to full manual and use an ISO that is one down from the highest the XT has.  I got rid of my XT long ago but I think (remember?) its top ISO was only 800.  This means you need to use 400.

 

Give this all a try and see what you think.  You just might get into it and decide a more modern DSLR is in your future.  There is no limit to what you can buy but what you have can shoot the night time skies.

EB
EOS 1DX and 1D Mk IV and less lenses then before!

TCampbell
Elite
Elite

How you do this depends on what you are trying to shoot and your equipment.  

 

You always need a good time and location.  Unless the image is specifically of the moon, you generally want a moonless night (check your calendar for dates near the "new moon" or if you're shooting in the evening then you also use dates near the 3rd quarter moon (the 3rd quarter moon is not in the sky after sunset... instead it rises a few hours before sunrise).  Light pollution is your nemesis -- you'll need to find a location which is away from urban light pollution (so if you live in a city ... a drive out to the country may be involved.)

 

For a "milky way" nightscape shot, you need a camera with (preferably) a very wide-angle lens and a solid tripod (emphasis on "solid" whenever long exposures are involved... anything shaky will result in blurred images.)

 

 

Speaking of things that can move... the Earth itself is moving and for a long exposure image of the night sky, it can be a problem (fortunately there are ways of dealing with it).  The Earth spins from west to east which gives us the illusion that we remain still while the sky moves from east to west.   This means if the exposure is too long then the stars will begin to grow "tails" and become elongated stars rather than pinpoint stars.  

 

When a very long lens is used (or the camera is using a telescope) the piece of sky visible in the frame is so tiny that stars move rather quickly from one edge of the image to the other (this can happen in under a minute).  But when a very short lens is used (wide angle lenses) the camera's field of view is an enormous area of sky and it takes quite a while for a star to move from one edge of the image to the other (this may take several hours).  This means if you use a wide angle lens, you have a better chance of captureing an astro image that has pin-point stars.

 

How long you can expose depends on the size of your camera's sensor and the focal length of your lens.  And it turns out there's a very easy rule for this.

 

The original rule was used for 35mm film cameras and it's called the"600 rule".  This rule says that if you divide 600 by the focal length of your lens then the result is the number of seconds you can expose and not have elongated stars.  

 

Suppose you have a 15mm lens.   600 / 15 = 40.  So that would mean that a 40 second exposure could be used.

 

BUT... this is for a 35mm film camera OR a "full frame" DSLR camera (such as a 1D X, 5D, or 6D body).  

 

Your camera has an "APS-C" size sensor which is 1.6x smaller.  All you do is divide 600 by 1.6 and that gets you 375.  That's YOUR magic number to remember.

 

Suppose you have a Canon EF-S lens such as the 10-22mm or the new 10-18mm and you use the 10mm focal length.  375 / 10 = 37.5.   Clearly you cannot dial in an exposure to precisely 37.5 seconds ... but you could use an external shutter release with a built-in timer.

 

Your camera wont let you set an exposure time longer than 30 seconds.  But it will let you select "bulb" mode.  In this mode you will also need a wired external shutter release with a timer (these are sometimes called "intervalometers" ... so if you shop online for one, remember that name).   If you don't have one, then you'll just have to program your camera for a 30 second exposure.

 

I will "caveat" that some photographers feel that the 600 value is a bit generous and they prefer to use slower values to play it safe.  You'll find references to the "500 rule" (it's the same rule... it just uses a more conservative value.)

 

So here's some bad news... 

 

I think your camera's maximum ISO setting is 1600 and you'll probably need to use ISO 1600 to get these shots.  At that ISO you're going to get a lot of "noise" in your images.  Newer cameras can shoot at much other ISO settings and show less noise and that's really helpful when shooting these types of images.

 

 

There are ways to shoot with longer lenses, take longer exposures, and use lower ISO settings and STILL have less noise.  But this involves using a special piece of gear generically called a "tracker" (tracking head).  This is a tripod head with a motor in it and it's speed can be set to rotate at the magic speed of 15 arc seconds (angular rotation rate) per second.  That's the speed that the Earth spins (technically 15.04 arc-seconds per second).  This head is oriented so that it's rotation axis is pointed at the celestial north pole (very very close to the "north star" (Polaris)) in the northern sky.   The camera can be attached via a ball head and pointed anywhere in the sky -- just so the rotation axis of the tracker head is pointed north.  This way as the Earth spins from west to east... the tracker head rotates from east to west and at EXACTLY the same speed.  As long as the tracker head's axis is parallel to the Earth's axis (this is why it must be aligned to the celestial north pole) the tracker cancels out the perceived motion of the earth and you can take very long exposures.

 

Here's an example I shot last January.  This is a single exposure using a tracker head.  I'm using a Canon EOS 60Da (it has the same sensor size as your camera) and a Canon EF 135mm f/2L USM lens (at f/11 -- which I normally would not use but this was a test).  This is a single 8 minute long exposure.

 

IMG_2719.JPG  

 

I was using a Losmandy StarLapse tracking head -- about $700 (it's a high-end head).  But you can get similar results from lower cost heads.  The Sky-Watcher "Star Adventurer" head has a base price of about $300 but for under $400 you can get it with the equatorial "wedge" (makes it much easier to set the correct angle) and they also offer a counterweight bar (with weight) which allows it to take heavier loads and still be "balanced" so the motor doesn't struggle and it tracks at a consistent speed.    iOptron makes a head called the iOptron SkyTracker (about $300) but for the money I'd go with the Sky Watcher head (the base price is the same but the accessories make it a better head than the iOptron head.)

 

When you move into this category you can take exposures of objects in the deep-sky but notice there is no "landscape" involved anymore... these photos only include 'space' (no landscape) because the land would be blurred due to the motion of the tracking head.

 

 

Tim Campbell
5D III, 5D IV, 60Da

 

https://www.reddit.com/r/astrophotography/comments/2acnqb/the_great_list_of_astrophotography_softwar...

 

I want to point out "Stellarium", "DeepSkyStacker", and "GIMP".

 

http://www.jshine.net/astronomy/dark_sky/  Dark Sky Finder, for finding locations not saturated by light pollution.

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"The right mouse button is your friend."
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