Astrophotography Setup Guide For When Out In The Field

We all love to spend time under the stars and peer into wonders the night sky offers us. But astrophotography is a tricky area, and before relaxing and enjoying the starry view, we often have to put up with quite a lot of technical and stressful tasks.

What is the best way to set up my gear?

If you are a beginner wanting to do astrophotography with your brand new tracker and feel lost when it is time to set up your gear, this guide is for you.

If you are a seasoned pro, it can still be an interesting reading.

How To Stay Comfortable When Under The Stars

Particularly if you don’t have the luxury to photograph from your garden, the secret to enjoying your time under the stars is to stay comfortable.

Nobody likes to feel humid, cold, tired, annoyed, unsafe, hungry, or thirsty, even if the view is great. 

Check out our other article where we discuss all the accessories one may need to have a comfortable time.

Before Leaving: Plan Ahead Your Imaging Session

Build Your Setup For The Night

A great plus of star trackers with respect to full-grown astrophotography mounts is their flexibility in the way you set them up. 

Before leaving your home, consider your location: if you need to hike and backpack with your gear, it is best to use a simple photographic tripod and keep your photographic equipment to a minimum. 

In this case, there is no meaning in dragging along a guiding system and a long telephoto lens or refractor, as the lightweight tripod cannot ensure the highest stability and performances required.

Instead, opt for starry landscapes and wide star fields astrophotography to take high-quality images even with such lightweight setup. 

Reserve heavier setups for places close to your parking spot.

Choose Your Target And Your Gear

If you work with photographic lenses, decide which targets you will go after and carry with you only the suitable lens. 

You can use Stellarium to simulate how the field of view changes for a target when you change the lens and/or the camera.

Test New Equipment And New Techniques Before Going To Your Location

If you have a new piece of equipment or want to experiment with a new technique, do that at home first, instead of wasting precious time at your location.

Say you want to start guiding your mount. Step out into your garden, balcony, or roof and test everything. You only need to find a guiding star, so you can do that even from within the city. No need to travel long miles to go under the darkest sky you can find.

On Location: The Proper Way To Set Up Your Equipment

Once you are at your location, it is time to set up your equipment. It helps to break down this process in steps and perform them in a precise order.

I devised a 12-steps procedure to set up my Star Adventurer, and this is the order in which I perform them:

1. Check Polaris is (or will be) in sight for precise Polar alignment.
2. Check the path of my intended target remains unobstructed through the night.
3. Set the tripod and check is stable.
4. Mount my tracker on the tripod and point it in the general North direction.
5. Do a first, coarse, polar alignment.
6. Mount my equipment on the declination bracket of the tracker without ball head with all needed accessories in place (red dot star finder, intervalometer, dew heating strips, filters, power banks…).
7. Make sure cables will not interfere with the tracker rotation. Remove the camera strap if present.
8. For better tracking, balance the payload slightly heavy east, to keep the gears inside the mount engaged and reduce the backslash.
9. Set the camera and focus on stars.
10. Sway the camera to the target.
11. Check and refine my polar alignment.
12. Take a test shot to confirm focus, polar alignment, framing, and camera settings all works as intended. 

When happy, I begin my imaging section and I lightly walk away from the setup.

These 12 steps are rather general, although fine-tuned to work with star trackers and astrophotography mounts with no GoTo. If you have GoTo, other steps such as three stars alignment may be required.

Here is some more info to help you with the procedure.

Check Polaris And Target Visibility

We all carry a computer in our pocket, and we can use it for more than just playing candy crush 🙂

Stellarium, Sky Safari, Sky Guide, and other apps can be used to check the location of your target in the sky and verify its path will remain unobstructed during the night.

Do This For A Rock Stable Tripod

A good, sturdy, and stable tripod is a must. Although not very portable, a tripod such as those from Berlebach or the SkyWatcher Stainless Steel tripod is the non-plus ultra for the best stability. 

If you do use photographic tripods, you may want to use a bungee cord to hang your backpack (or a bag of rocks) to the tripod to pinning it to the ground. 

But be careful not to leave the bag hanging mid-air: this will create vibrations. Instead, have the bag grazing the ground, so that it cannot swing.

On soft ground, you can use a tent peg hammered in the ground as an anchor point for tensioning the bungee cord.

Also, on soft ground (beaches, mud, wed grassland) have something like three wooden disks to place under the feet, to prevent them from sinking in the ground. Flat rocks you can find at your location will also work.

Finally, keep the photographic tripod reasonably low on the ground by only extending the larger sections of the legs. 

By doing this, you ensure the tripod to offer the best stability for your equipment, at the cost of a much less comfortable polar alignment, as you will have to kneel or sit on the ground.

Knee pads like those used by construction workers are great to keep your knees dry, safe, and comfortable when kneeling on the ground.

Master Your Polar Alignment

This is probably the most crucial step of all. If the concept of polar alignment is universal and simple to grasp, put it in practice is another story.

The way one polar align the mount depends on the kind of polar scope the mount has. With some, the location of Polaris on the reticle is set in relation to the position of other stars. Others use the date, time, latitude, and longitude for your location.

Some methods require the mount leveled on the ground, while others have no such requirement. 

I have discussed all the aspects and intricacies of polar alignment in this article, and you can find instructions specific to the SkyWatcher Star Adventurer PRO in our ultimate guide.

Nail Your Focus On Stars

Even if you nail the polar alignment, you can still screw everything up by missing the focus on your stars.

You can read all you need to know with our guide on how to focus on the stars. Have a look at it and never miss the focus again.

Use The Proper Camera Settings

Astrophotography is all about recording faint light. But that does not mean you have to set your lens to the widest possible aperture and use the highest ISO value your camera has, etc.

Because camera settings depend on too many factors, there are no goto, failsafe, settings you can memorize and use blindly.

Instead, it is much better to understand the criteria you must use to choose the best possible camera settings for your equipment, target, and sky conditions. 

Ask me “how should I set my camera?” and this is what you will get from me:

You must set the lens to the widest usable aperture, the camera to the lowest ISO settings for which your camera is ISO invariant, and use the longest usable shutter speed.

Here there are two concepts to understand: usable and ISO invariance.

When used wide open, many photographic lenses produce images that are somehow soft and lack contrast. The image is also affected to a certain degree by optical aberration such as coma, chromatic aberrations, and purple fringing. Vignetting is not a problem, as we can cure it with flat frames.

If you step down your lens of 1 stop, these problems are often greatly reduced, if not entirely eliminated. Therefore, experiment with your aperture settings and find the widest aperture you are happy with and stick with it.

Tracking errors due to the quality of your polar alignment, payload balance, and the mount periodic error becomes more evident when using long focal lengths. 

If you can expose the sky for 5 minutes with a wide-angle lens with no problems, with a 300mm lens, you may find that exposing longer than 1 minute will force you to reject 90% of your images, because of visible tracking errors.

Find the maximum exposure time you are comfortable with for a given lens. Sometimes it is better to use a shorter lens and drizzle in post to close in on your target.

Finally, there are a lot of misconceptions about what ISO is and how it affects an image. I invite you to read this article we wrote on ISO and ISO invariance. 

In short and in layman’s terms, in the ISO invariant regime, every ISO value will give the same amount of noise once you brighten up the image in post. 

But since the higher the ISO, the smaller the dynamic range your sensor can capture, use the smallest ISO invariant setting for your camera.

Finally, a word about the histogram: since the peak is a measure of the sky brightness, limit yourself to have the histogram peak about ½ from the left edge, and no less than ⅓.

This means that with bright skies, we favor the number of images over the length of the single exposures, to counteract light pollution. With darker skies, we can take longer exposures for better images.

Must Have Accessories For Your Equipment

A number of accessories will make your life easier when setting up in the field. Here is a quick list of items you should consider having:

• a headlamp that can switch between white and red light. Use the red light to avoid spoiling your night vision;
• Also carry backup power sources: AA batteries for the mount, AAA batteries for headlamp and intervalometers, CR2032 coin batteries for red dot star finder, power bank for everything else that is not powered with batteries. And don’t forget a spare battery for your camera.
• Polar scope illuminator, to see the reticle and help you to identify Polaris among the stars visible through the scope;
• A right-angle viewfinder for the polar scope to improve your comfort while doing the alignment, sparing you to kneel on the ground;
• Knee pads for construction workers will make kneeling more comfortable;
• Leveling base, to help you level the mount more precisely than by fiddling with the tripod legs extension. This is a must-have only if your polar alignment method requires the mount to be leveled on the ground.

• Dovetails Clamp And Rails For Better Payload Balance.

• Red Dot Star Finder And Dew Heating Strips.

Video Tutorial

Here is a video I made to demonstrate how I set up my gear in the field.

Conclusion

Setting up your gear properly is an art one will master with time and practice.

Even if every setup is different, the steps we discussed are quite general and give you an idea of how to proceed. And the tips will make your setting up faster and easier.

Now is your turn to go out there and practice for getting the perfect setup.