Take Incredible Moon Photos with a Telescope and Smartphone

Take Incredible Moon Photos with a Telescope and Smartphone

If you always wanted to learn how to take stunning closeup photographs of the Moon, then this article is for you!  I have been taking and posting my Moon pictures for years, and here I explain, in detail, how I create these pictures that I post to my blog and other outlets like (see my Contact page).  The process is easy and only needs a small set of equipment, along with patience and practice.

My guide is not absolute – there are many ways and methods for taking pictures of the Moon and other objects in the sky.  But through many trials, I have found this method to be the best, for me, and should at the least provide a starting frame of reference for taking your own pictures.

The First Big Variable: The Telescope

The title of this article says, “Telescope and Smartphone.”  Hence, the telescope is an important part of the complete equation.  If you point your smartphone to the Moon on any given night, yes you will get a picture, but the Moon will be really, really tiny.  So the telescope acts as a giant lens.

The method of photography employed here is known as, “afocal.”  Afocal means using an existing camera lens (whether phone, DSLR, or any type of camera) pointed up against the eyepiece of a telescope.  There are several layers of glass between the object (Moon) and the camera sensor, so this is not the most efficient method if you truly want the greatest detail.  But the Moon, in the context of the Universe, is an extremely close and bright object, so in practice there will be no noticeable difference in image quality so long as your telescope’s focus is good.

So back to the telescope…any telescope, large or small, will do.  Most beginner telescopes are refactors.  Read more about choosing a first telescope here.  For this article’s example, the telescope I used was my 10-inch / 254 mm Dobsonian.  Dobsonians are a type of Newtonian reflector (originally invented by Sir Isaac Newton), and they require a special pre-step called collimation (adjusting the mirrors).  Though all telescopes do require collimation, common refractors should only need it rarely, if ever frankly.  My 127 mm Maksutov-Cassegrain (“Mak-Cass”) telescope is a special type of reflector and should only need collimation if there is serious work done to fix the telescope.

The important point here is that any telescope will do, just as any modern smartphone with a camera will do.  Just keep in mind that the aperture (size) of the telescope is one of the main variables that determine how large the final Moon image will be.

Second Variable: The EyePiece

The other main variable for the size of the final image is the eyepiece.  The eyepiece’s diameter will greatly determine how large the Moon’s surface area will appear, both to you and to your phone.

Most telescopes will come with two eyepieces, a wide and a narrow.  For photographing the Moon, you will want to use your wide eyepiece.  The narrow eyepiece, typically in the 6 to 7 mm range, will (1) have too small of a lens hole to position the camera effectively and (2) not show the entire Moon’s surface.

For this demonstration, I used a basic 23mm eyepiece, which I have found to fit the Moon very well on both of my telescopes.  It is also very forgiving when it comes to attaching the smartphone telescope adapter to the eyepiece and centering/positioning it properly.

Also, be careful not to go the other way by choosing an ultra-wide eyepiece (e.g. 60-70 mm), intended for wide-field deep sky object viewing.  They will make the Moon appear noticeably smaller, unless that is the effect you are going for.  I recommend keeping somewhere in the 23 mm range.

Equipment Used

Here is a list of all of the equipment that I employ for my Moon imaging.  Some of the items you likely already have, and I will explain the others.

Please reference the title image of this article for a visual of each small item.

  • Telescope – as explained above, nearly any telescope will suffice
  • Smartwatch – wait, what?  What is the purpose of a smartwatch?  When it comes to using my phone attached to my telescope to take pictures, I have found that the smartwatch is an invaluable remote control for the phone’s shutter.  Because every time you touch the phone to activate the shutter, you are creating a small vibration through the telescope.  This naturally impacts the quality of the image.  While it is possible to set a time delay, using the watch as a remote allows rapid consecutive imaging from a distance, free of any vibration.
  • Smartphone – in my case, I use my iPhone XS
  • Pliers – (DOBSONIAN ONLY) I used the pliers to adjust the position of my Dobsonian’s primary mirror.  If you don’t have a homemade Dobsonian, you will not need pliers.  If you have a commercial Dobsonain, it likely has hand screws to collimate the mirrors.
  • Red flashlight – I have found having a red flashlight handy in the dark is useful for keeping my night vision, even though night vision is not terribly important for the Moon (it is more important when observing deep sky objects like nebulae and star clusters, or trying to find Pluto).
  • Telescope eyepiece – My 23 mm eyepiece.  As explained above, try to use an eyepiece in this diameter range.
  • Laser collimator (DOBSONIAN ONLY) This is for precisely lining up a Dobsonian’s mirrors.  If you have a Dobsonian, you likely already have a device like this.  So if you don’t , don’t worry about it!
  • Phone telescope photo adapter – Some may consider this optional, but I consider this absolutely necessary.  If you do not have an adapater to secure your phone to your telescope’s eyepeice, you will need to have a very steady hand to hold the phone up to the eyepiece.  Possible, yes, but I believe this is a case where a little product investment more than pays off.  I use this adapter from Orion.

Before We Start, Note on Bulging Cameras Lenses

Please take a moment to look at the image of my iPhone XS above.  Notice how the phone’s cover allows the phone’s lenses to be flush with the cover’s surface.  Having this flat/flush surface is very important for when you secure your phone to the telescope adapter.  The iPhone XS is four years old now, and the “bulge” is very modest, but newer phones have a much more pronounced, protruding camera.  If you have one of these newer phones (and I will whenever I refresh my phone), you will need a phone cover, or some other means, to ensure the camera lens is flat up against the telescope adapter mount.

Step One: Choosing the Time, Location, and Moon Phase

A little planning ahead will be beneficial.  For example, do you know what the current Moon’s phase is?  There are plenty of resources online to determine this and for your location.  If you prefer to observe the sky in the evening, like me, then you will be wanting the Moon when it is a young crescent to Full.  Once the Moon is Full and beyond, the Moon will rise later and later, eventually past midnight local time.  Early risers who want to photograph the Moon will be seeing the later phases as the Moon dwindles back to its New phase.

Because the Moon is so bright, you can photograph it practically anywhere, even in cities afflicted with severe light pollution.  So long as your view of the sky, and particularly the Moon, is not obstructed, you will be fine.

The weather is also a factor, as you will want relatively clear skies.  Some clouds, even more clouds, are usually fine, if you are patient and willing to allow them to pass or to find an opening in the sky.  I have found that cloud cover can make for interesting photographs.

On the night of this demonstration, I saw the forecast was Partly Cloudy.  But the sky was clear all night, at least for the time I was outside with the telescope.  I noted those rain showers in Iowa, below, were well away from me, so I was reasonable sure I had enough time this night for a telescope session.

Step Two: Telescope Setup

Your telescope setup will vary based on the specific type.  If you have a refactor and tripod, you simply need to set the tripod up and attach the telescope to it, if not already done so.  You will want to use the firmest and steadiest floor surface available to you.  But note this, that you probably do not want to place the telescope over asphalt/pavement after a hot day, because asphalt stores heat through the day and releases it at night.  This will impact the telescope’s mirror/lens and distort the image.

You will also want to allow the telescope to “cool” (or warm) outside so the equipment acclimates to your immediate outside temperatures.  In general, the larger the telescope, the more time you should allow.  For my 5-inch / 127 mm Mak-Cass, I give it about 20 minutes.  For my 10-inch / 254 mm Dobsonian, I allow at least 45 minutes, and try for at least an hour.

For my homemade Dobsonian, the setup requires me to take its two main components outside onto my deck separately.

An advatange of a Dobsonian over some other telescopes is that it is extremely easy to transport and re-assemble.  All I have to do it lift the tube onto its swivel mount, an I am done!

I like to swivel the telescope towards my target for the night, so that I confirm I have enough clearance all around:

Notice that I did all of the above in daylight, within an hour of Sunset.  This is the point where I let the telescope settle for at least an hour, and would come back to it later once the sky was sufficiently dark.

Step Three: Collimation (Dobsonsian Only)

You only need to perform collimation if you have a Dobsonian and/or reflector telescope like I do.  And if you have this type of telescope, likely you already know the process.  But for reference, here is how I collimate my Dobsonian before any session, whether photography or just observation.

Collimation involves adjusting the secondary (small) mirror first, followed by the main primary mirror.

Once the telescope has settled to the outside temperatures, I attach the laser collimator to the eyepiece holder, and turn it on:

On the laser collimator is a “bullseye” and I ensure this is pointed towards the back of the telescope so that I can align the laser in a moment.  Once the collimator is on, I peer down the telescope’s tube.  At the center of the primary mirror is a little sticker marker, and I should see the laser, bouncing off the small secondary mirror, somewhere near the sticker.  I must manually wiggle the three balsa wood legs bracing the secondary mirror until the laser points as close to the center of the primary mirror’s sticker as possible, like so:

It is a little hard to see, but the middle of the primary mirror, at the back of the telescope, is glowing red from the laser.

Once the front of the telescope is set like this, I need to go to the back of the telescope.  One my homemade Dobsonian there are three bolts that control the positioning of the primary mirror:

Like I did with the secondary mirror up front, I must move the primary mirror, via the three bolts and using the pliers, to align the laser in the middle of the collimator’s bullseye.  Usually, I only need to twist the top screw a bit:

On a commercial telescope, you likely will have thumb screws or similar to twist easily with your hands.  My homemade Dobsonian uses these manual bolts moved by my pliers, as shown above in this article.

Once the alignment is finished, I turn off the laser collimator, and replace it in the eyepiece mount with the actual eyepiece I will use for the evening’s telescope session.

Eyepiece in telescope, with cap still on. The phone adapter will attach to this eyepiece (once the cap is removed).

Step Four: Preparing the Phone

This part may be done at any time, and I usually do it while the telescope is adjusting to the outside temperature.

Attach the phone to the phone adapter.  It takes a little practice to align your phone exactly to your adapter.  I recommend pointing the phone, with a camera app active, to a bright location to help with centering it on the adapter.

Firmly secure the phone with the thumb screw on the back.

Step Five: Focus!

Before proceeding further, you must focus, literally, your telescope on the Moon.  How you target and focus on the Moon will, again, depend on your specific telescope.  You want to get as good of a focus as possible before you attach the phone and adapter to the eyepiece.

Practice is always the name of the game here.  In fact, I recommend being comfortable with using and focusing your telescope before you attempt Lunar imaging.  How to focus on the Moon, observe, and appreciate the sight should be second nature before attaching your smartphone to the telescope and taking photos.  Patience is best.

Step Six: Continual Calibration

The phone is mounted to the adapter.  The telescope is focused and mostly pointing the correct position towards the Moon.  Now you may attach the adapter to the telescope.

Again, this is all about practice.  A key concept here is to remember that the sky is always moving.  So unless you have a computerized mount tracker, you are going to have to keep adjusting your telescope slightly to keep the Moon in view.  Practice, practice, practice, again before you attempt smartphone imaging is best.  The Moon will move out of view, but it’s a slow move and you need to learn how to gradually nudge the telescope to keep the Moon within sight of the eyepiece.

Try to mount the adapter as flush with the eyepiece as possible.  Never tighten the adapter too tight.  I have found it best to leave a very small gap between the top of the eyepiece and the bottom of the adapter.  It is also best to do all of this in a dark area to avoid unwanted light from bleeding into your phone’s camera view.

Here is how I typically have my phone mounted to my Dobsonian telescope, with the Moon in view, focused, and ready to snap a few photos before the Moon drifts out of the eyepiece yet again:

Live Moon capture with my smartphone attached to my Dobsonian telescope.

I use both the iPhone’s stock camera app as well as the NightCap app.  Lately, I have been gravitating more towards NightCap, as I have great control over focus, exposure, and ISO.  Adjusting all of these settings takes practice as well.  On nearly all of my posted Moon articles, I include at the bottom the specific camera settings for the final image.

For the Moon at about the Quarter Phase, like in this demonstration, I will generally keep the ISO at 24 (lower is better to reduce noise) and exposure ranging from 1 / 250 seconds to possibly as short as 1 / 1500 seconds.  1 / 2000 seconds will make the Moon too dark at this phase, in my opinion, at any aperture.

NightCap is also handy with its Apple Watch app acting as the camera remote control.

Step Five: Choosing the Raw Images

How many photos I take at the telescope depends on a variety of factors.  For a Lunar Eclipse (a “big” event), I snap well more than 100 images, perhaps 200.  For a normal Moon session, my image count hovers around 30 to 40.

Choosing which images are “best” is more art than science.  You definitely want to eliminate the ones that are out of focus.  Then it is a matter of which pictures you feel accentuate the details of the Moon best.  For this demonstration, here is a sample of the file pool I looked through.

Once you have the picture you feel is best, you are essentially done.  Great job!  You can share that picture to your friends and family and they will be amazed.  But if you want to go a little further and put finishing touches on your picture, continue to step seven!

Step Seven: Post-Processing

As alluded right above, this step is entirely optional, and how you do it depends entirely on your post-processing preferences.  But in general, you want to adjust the image for gray, sharpness, and cropping.

I use Corel PaintShop Pro 2018 for all of my image editing.  How to use a paint program is its own topic, but here is how my picture looked in PaintShop Pro while I was editing it:

Post-processing my Moon image in Corel PaintShop Pro 2018.

Finding “middle gray” is an interesting task that is easy once you get used to it.  I am sure it is slightly different in other paint programs, but here is the great guide I always refer back to for my specific need:

In PaintShop Pro, here is part of the interface for using the dropper to find middle gray.  There is a lot of gray on the Moon, so sometimes I just hunt and peck until I find the shade of gray I like for the image I am working on.

Another point…notice how the Moon is pointing in different directions in my raw image list and in PaintShop Pro, above?  Dobsonian telescopes, and others, flip images, so you may need to flip your photo accordingly to get the true perspective, if you feel that is important.


Conclusion

Here is the “raw” image taken from my iPhone at the telescope, converted from its raw format to a JPEG for web viewing:

…and here is the final post-processed image, adjusted for middle gray and sharpness.  I increased the sharpness a bit more than I usually do.  How you make post-processing adjustments will be specific for your own equipment and camera, and your own preferences and tastes.

Here are this specific image’s camera and telescope settings:

Equipment Used:

  • 254mm Dobsonian telescope (homemade)
  • 23mm eyepiece
  • No eyepiece filter
  • iPhone XS
  • Smartphone telescope eyepiece adapter
  • Nightcap app on iPhone
  • f/1.8
  • 1/1266 sec exposure
  • ISO 24
  • Focal length: 4mm
  • Minor touchups in PaintShop Pro and AfterShot Pro

I hope you will find this guide useful and take your own Moon photos.  If you do, I would love to see your final pictures!  Please contact me for questions by leaving a comment on this article below, or via my Contact page.

Paul

Paul

I write frequently about astrophotography, technology advice, and my other interests like science fiction. I have over 30 years of experience in computer programming, information technology, and project management.

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