Next Steps in Learning Deep Sky Astrophotography – An Equatorial GoTo Mount

One of the next pieces of equipment I purchased that really improved my astrophotography was Equatorial GoTo Mount.  A GoTo Mount will improve and assist your astrophotography in several ways:

• Precise location and slewing (moving) to Deep Sky Objects in the night sky
• A heavier payload, for bigger lenses, telescopes, and accessories
• Ability to use polar alignment devices for a more accurate polar alignment and longer exposures without star trails
• Ability to add autoguiding to your set up for even longer exposures of deep sky objects

For my first Equatorial GoTo Mount, I picked the Sky-Watcher HEQ5 mount.  I selected the HEQ5 for a couple of reasons.

• The HEQ5 has a 30 pound payload capacity so I can use all my current gear plus have room to grow into a medium sized telescope if I desire.
• The HEQ5 weighs about 23 pounds without the counter weight which means I can keep the unit set up in my garage and carry the HEQ5 assembled with the camera, lens, and guide scope out to my site in the backyard.

It is recommended to stay within 2/3^rd of the weight capacity of your mount.  For the HEQ5, this is around 20 pounds.  Note: the counter weight is not included in the calculation.

So, what can you mount within the 20 pound weight capacity.  Below are some examples based on my DSLR gear:

As you can see, DSLR configurations with a guide scope will have plenty of room within the 20 pound limit.  Even if I throw in a Canon 500mm f/4 IS lens with the 5d Mark III (12 pounds), you have plenty of room under the limit.  This also means you have room to grow into a mid-range telescope.

Using the HEQ5 with a DSLR Camera and Lenses

Initially, I had a couple of challenges using the HEQ5 with DSLR gear. 

The counter weights included with the HEQ5 (11 lbs x 2) were too light to balance with my DSLR and lenses.  I ordered a 7.5 pound counter weight from B&H Photo and that works fine with my DSLR configuration.

The V-Style Dovetail Saddle that is included with the mount is meant to attach telescopes to the mount.  I ordered a dovetail plate that fits narrow vixen-style saddles in order to attach my DSLR lenses to the HEQ5 Saddle.

Features of an Equatorial GoTo Mount

I wanted to go a bit deeper into some of the features of a GoTo Equatorial mount that I mentioned above.

GoTo Database

Equatorial GoTo mounts have a database with the location of 10s of thousands of night sky objects.  The HEQ5’s SyncScan system has 42,900+ objects.  These include galaxies, stars, nebula, planets, etc.

To accurately find these objects, you will need to enter your GPS location and altitude into the HEQ5 mount.  The HEQ5 will remember these settings after you enter it the first time.  Of course, if you change locations you will need to reenter the information.

You will also need to do a 1, 2, or 3 star alignment after you polar align your mount.  I usually do a 2 star alignment.  I find this gives enough precision.  This is all done with the hand controller.

Once you have completed the star alignment, you just need to punch in the catalog number for the DSO (M31 = Andromeda Galaxy).

Polar Alignment

I don’t know about you but sometimes I have a hard time getting an accurate polar alignment using the polar scope in the mount.  Adding a polar scope like the QHY PoleMaster can greatly improve the accuracy of your polar alignment.  This will mean adding a laptop to your set up but you will want to do that anyway for autoguiding and using image capture software.

Autoguiding

Autoguiding will let you increase your exposure lengths from 3-4 minutes to 7-8 minutes or more.  GoTo mounts have an autoguiding port where the mount will accept guiding correction messages from auto guiding software like PHD2 for more accurate tracking.

You will need to add a guide scope and camera to your configuration and use a laptop with auto guiding software to enable autoguiding.

You don’t need to add all these pieces to your astrophotography configuration at once, but make your you consider your future astrophotography goals when choosing a GoTo Mount.

Deep Sky Astrophotography Tutorial – Table of Contents

Written by Martin Belan

Related Posts

Mindset and Tips for Learning Deep Sky Astrophotography
How to Mount a Guide Scope to Your DSLR / Mirrorless Camera without a Telescope
Learning Deep Sky Astrophotography – Planning Your Composition