DSLR Quick Start
Getting started with a DSLR[edit | edit source]
written by /u/Orangelantern
So, you have a DSLR, but don't have anything else. That's great news! A significant portion of the money new people spend getting involved in the hobby is usually on a DSLR. Yes, just about any DSLR will do for these beginning steps, however Nikon and Canon cameras have the best software compatibility. If it can do Bulb mode, or even just 30s exposures, you are totally set when it comes to getting started. If you already own a DSLR, chances are you have a tripod too. If you don't have one, you will need to go get one.
Bare Essentials[edit | edit source]
- Your DSLR,
- A Tripod,
- A Remote Shutter Cable or Intervalometer
- A wide lens (sub 35mm)
To get started, simply put your camera on your tripod, and go outside. If it isn't dark yet, give the earth some time to rotate. Start thinking in terms of celestial movement!
Keep your tripod legs short, having them fully extended could negatively impact your image through vibrations caused by you and other sources, and wind.
Now you need to focus your lens on the stars. If you have live view functionality on your DSLR this becomes much easier. First, set your ISO up decently high, nearly as high as it can go. You'll want to find a bright star (NOT THE SUN!), and point your camera towards it. If the moon is up, keep your ISO low and your exposures short. Point your camera towards it, ideally putting the star you're focusing on near the center of the frame. Choose whichever f/ you want to use for the night, as changing this later will likely require you to refocus. For most lenses, generally one or two stops down is best to avoid excess aberrations near the edges of your shot.
Focus on the star or moon. You'll want to get the star as small as possible. In the case of the moon, adjust your focus until you are happy with the level of detail you are seeing on its surface.
Make sure your cameras auto focus is turned off! You can spend minutes getting the perfect focus, only for the camera to ruin it in a moment. Set your camera to manual focus mode, and if the option is available on the lens, set the lens to "MF" or Manual Focus.
Next, set your ISO lower, to whatever you feel your camera is capable of performing well at. For these purposes, ISO essentially equals Noise. Your image will look brighter, but your image will also be noisier. Too high, and your image will be very noisy. Too low, and you wont catch a ton of stars. On my Canon T3i, and on my Nikon D5500, I usually set an ISO of around 800. Experiment with your camera to see what you think is best. Don't forget, you're going to be editing these photos later on.
Make sure your camera format is set to RAW mode. JPEGs are completely useless in the case of Astrophotography. Also, turn off in-camera noise reduction. You can do this later.
If you have a remote shutter cable, plug it in. If not, try and be as smooth as possible.
Set your exposure time to something short, just to try it out. Set your exposure time to 10s, and hit the shutter.
3...2...1... Done! Congratulations, you are now an Astrophotographer.
Check your picture. Does it look like there are streaks in the stars? Do they look properly focused? If you are using a low focal length, like 18mm, you shouldnt be seeing much trailing at 10s. If you aren't using a remote shutter cable, try it again, and try to be smoother with your movement. Also, go buy a shutter cable or intervalometer. They're pretty cheap, you can find one online for less than $15.
Now go ahead and try a longer exposure. You will likely max out at around 20-25s before there is noticeable trailing due to the earths rotation.
3...2...1... Done! This image should look brighter and with more stars than the 10s shot.
Now, its up to you. You could shoot several more of the same area, move your camera to another part of the sky, or whatever you fancy.
From here on out, you will likely begin to fall into the rabbit hole that is this hobby.
Next Steps[edit | edit source]
From here, you can try and do something called Stacking. This is when you take several images of the same thing, and "stack" them together to improve your signal to noise ratio. Noise is mostly random. By taking several shots, you are keeping your signal the same, but your noise will be different. This allows you to essentially average out your noise, while improving the ability to see the objects you photographed. If you want to stack, it is best to take shots that don't include any landscape, as it helps with the stacking algorithms.
You may also decide that you want more exposure time. If you want to shoot longer, you are going to need a tracker or mount. Something that will make your camera "follow" the stars. In reality, it is actually cancelling out the Earths rotation. More on that here. Depending on your goals, you can choose a cheaper lightweight tracker, or a beefier more expensive mount. Both will work great for widefield, but for higher focal lengths I recommend using a beefy mount.
Finally, here is a list of dedicated, some free, software that can help you stack, post process, and get to know the sky.