How to do Deep-Sky Astrophotography Without a Telescope

No telescope? No problem! You can still shoot deep-sky astrophotography images like a pro.

What can you shoot without a telescope?

The short answer: almost anything! Remember, a telescope is just a big (huge) lens. When shooting astrophotography without a telescope, you are only limited by the magnification of the lens you are choosing. Luckily, the number of available targets worth shooting with just a standard camera lens is huge!

1 Gather your equipment

Camera

Your normal DSLR will do just fine! It always helps to have one that has been IR modified (replacement or removal of the stock standard infrared filter) so you can capture that beautiful red hydrogen alpha (Ha) that is the stuff of most emission nebulae. Regardless — this is NOT a necessity.

Another choice, if you want to up your game, is an astronomical cooled CCD camera. These are definitely the stuff of the best astrophotography photographs out there, but it’s big step from the standard DSLR methods.

Lens

This is where it’s easy — almost any good-quality lens will do. You are going to be able to shoot very long exposures, only limited by the sky conditions and your mount’s sky-tracking quality, so even a quality f/4 lens will do just fine. Fast is nice, but not required.

Tracked wide-field images can look amazing with lenses from the 24-50mm range. And a zoom lens, anywhere from 100mm-300mm can work wonderfully with nebula and even large galaxies, like Andromeda (M31).

Read our tutorial on how to use the free application Stellarium to choose the perfect focal length for your target!

Tracking mount

Some of the best advice for a beginner astrophotographer is to buy the best mount your money can buy, and get the telescope later.

That being said, if you plan to travel a lot and need something small, or if you only have aspirations for DSLR and camera lens astrophotography, then a smaller budget mount can work wonders for you.

For larger mounts, we can easily recommend the Celestron Advanced VX mount. It will hold far more than just a camera, so when you get a telescope, chances are it will handle it just fine. When you’re ready to upgrade and add the telescope, check the payload capacity of your mount to ensure it can accommodate it.

Some of the smaller recommended mounts that can be used on standard camera tripods are the SkyWatcher Star Adventurer, iOptron SkyTracker, Vixen Polarie, and the Astrotrac. These are great for travel portability and quick setup.

Once properly polar aligned, they can all offer several minutes of accurate tracking to keep the stars in your images round. Usually exposure times of around 3-5 minutes are possible depending on the weight of your camera and lens, and setup. Most often this is more than enough time to capture your target.

Tripod

As with any astrophotography equipment, you’ll need a stable, heavy-duty tripod. You are going to be shooting very long exposures, so the slightest movement will ruin the photo and cost you minutes of time. Luckily, most of the smaller mounts like the SkyWatcher Star Adventurer, iOptron SkyTracker, Vixen Polarie, and the Astrotrac can be used on conventional camera tripods. Most of the larger mounts like the Celestron Advanced VX will come with their own tripods.

The keys to getting it right are stable legs, heavy weight, and keeping it low. Try and keep the tripod legs as short as you can cope with to minimize risk. If the tripod doesn’t have a lot of weight by itself, add weight by hanging something heavy from it. One of the things I often do when traveling is hang my camera bag with rocks in it from the center column of the tripod. Heavy is stable!

Optional: autoguiding (advanced)

Depending on the mount you choose, you may be able to also set up an autoguiding interface for increased quality and longer exposures.

This requires a special input port on the mount and often, a connection to a computer to control and correct your mount. The autoguiding camera and lens (telescope) will add to the overall weight of your system, so you’ll need a beefier mount to keep things on track. Once a successful autoguiding system is in place, however, the ability to capture far longer exposures is enabled. 10-30 minute exposures (or more) are possible using systems like these.

Most often, an autoguiding system is best utilized for use with cooled CCD cameras, as DSLR cameras get too noisy as the sensor heats up after a few minutes.

Other equipment

Some of the following will be required depending on what you choose for a setup:

• Remote shutter release cable
• Computer (for autoguiding and/or tethered image capture)
• Power source for the mount
• Extra camera batteries or external camera power (recommended)

2 Pick a target

Not unlike using a telescope, choosing your target is going to be highly focal length dependent. How long your lens is and what you can fit with good detail in the field of view will dictate what your best choices for targets will be.

A large galaxy like Andromeda (M31), around 8 full moons in apparent width, will look great in a 200mm lens. Pleiades (M45), the Carina nebula, and other large objects also work well at 200mm with a full-frame camera, and even better with a crop frame DSLR.

A great way to pick a target that fits perfectly within the field of view of your lens and camera choice is with the free application, Stellarium. Read our tutorial about how to use it!

Luckily you’ll have a lot of options with a typical telephoto zoom lens. For example, these were shot at 135mm on a 70-200mm lens and a full-frame Canon 5D.

Even shooting wide at 24-50mm can give you some beautiful results!

3 Set up your mount and tripod

Mount setup is the key to getting round stars and sharp details for each photo. Take the time to do it properly!

Balance and leveling

For accurate tracking of the stars, the tripod and mount will need to be as perfectly level as possible. Many will have a built-in spirit level to help, but remember to not always trust them without a sanity check.

Some mounts don’t have a counterweight system, like the iOptron SkyTracker and the Vixen Polarie. If this is the case then you obviously don’t have to worry about it.

For the mounts that can handle more weight, proper balance is important for the motor of the tracking mount to run smoothly and move with the stars accurately. Be sure to set the counterweight on the RA axis correctly so that the camera moves easily in both rotational directions. It is sometimes necessary to slightly set the weight balance a bit heavier in the up direction of the motion to keep even stress on the gears, but not likely for lightweight camera applications like this.

Polar alignment

Ensuring that the polar axis of the mount is as accurate as possible, it’s a make-or-break step to success with a tracking mount. No matter how good your balance, motor speed, and mount quality is, if you don’t take time to polar align, you’ll get egg-shaped stars at best, or ugly trails at worst. Once polar aligned, you’re going to trust that your mount is pointed at the celestial pole so when you turn on the motor(s), it will track as perfectly as possible to maximize your exposure length.

If you’re using an autoguiding system, check out this tutorial detailing how to easily polar align with PhD!

4 Capture the data

At a minimum, you’ll need to use a remote shutter release cable with your camera in bulb mode. For best results, attach the camera to a computer (or mobile device) for remote shooting and camera control.

DSLR settings

ISO
Now that you are able to shoot for longer duration without the stars trailing, you can dial the ISO speed down to keep the noise to a minimum. Anywhere from 400-800 is just fine, and a good starting point.

Aperture
Depending on the quality of the lens you are using, it is always recommended to stop it down bit from wide open. This will make your stars sharper, and the image will be of higher quality in general.

For example, if you don’t like what you see from a long exposure (zoom in all the way!) at f/2.8, drop it down to f/3.2 or even f/4. Testing your lens is the best way to decide what it can handle!

Exposure length
If you’re properly balanced and polar aligned, and not using an autoguider, you should expect to be able to achieve photos with round stars at up to 5 minutes with wider lenses (24-50mm) and around 2-3 minutes with longer focal lengths (100-300mm). Your mileage may vary with this, depending on your imaging setup and tracking quality, so again some testing will be required!

Other settings
Shoot raw, as always!

Set the color temperature the same as you would for wide-field astrophotography, but remember it can be changed in post when you shoot raw. See this article for tips on choosing the right white balance.

Turn off long-exposure noise reduction and other in-camera noise helper functions.

Disable all image stabilization features of your lens.

How many frames to shoot

The more the better! Capture as many light frames (images of your target) as possible if things are going right. However, in addition to the light frames, you’ll need to save some time to shoot darks — so while the ambient temperature is still stable, don’t forget to set aside time for around 25-30 dark frames at the end of your imaging session. Flat frames and bias frames can be made later, after you’ve gotten some sleep, if you’re careful.

Don’t think calibration frames matter? Read this article!

5 Process your images

Once your data is captured, it is processed using the exact same method used for telescopic deep-sky images.

Calibration frames

When using a DSLR and standard lens for deep-sky imaging, you are still much better off to create calibration frames for the best results. Shooting darks, flats, and bias will exceptionally increase the quality of your final image. See our tutorial on how to easily shoot flat frames!

Stacking

You’ll need to combine your captured images using a specialized computer program. This drastically increases the overall quality by reducing noise and boosting faint details.

Not sure if stacking is worth it? See this article! If you want to give it a try and practice on some my data, I’ve got that waiting for you as well, right here.

There you go — get started now! Have questions? Fire away in the comments!