Early Morning Glimpse of Saturn and Jupiter

Objects in the early morning sky. Left to right: Saturn, Jupiter, part of the constellation Sagittarius.

June 16th, 2020, 03:22 a.m. local time

I happened to be up early mid-morning and decided to check on Jupiter and Saturn.  I knew from my observations last week that they should have been almost due South, and my direct observation confirmed this.  The above picture was hastily taken with my phone.  Interestingly, this is the stock iPhone camera app, versus NightCap.  Normally, NightCap gives better ad hoc photos of the sky, in my experience, but this time, NightCap’s TIFFs were too dark.

Jupiter is the big bright object near center.  Slightly above and to Jupiter’s left (from our vantage) is Saturn.  You can also see sloping towards the right some of the brighter stars in the constellation Sagittarius.

This picture also emphasizes how bad my location’s light pollution is.  That glow towards horizon is not the Zodiac lights, but the overabundance of artificial illumination even after 3 a.m.

Edit: Zooming into the image, I noticed a star was captured above and slightly left of Saturn.  According to Stellarium, that is the (double) star Dahib, brightest star in the constellation Capricornus.

Saturn, Jupiter, and Moon, Early June Morning, 2020

Objects in our Solar System. Top row, left to right: Saturn, Jupiter, Moon. Bottom, Earth.

June 8th, 2020, 02:30 a.m. local time

We* here at Aperture Astronomy will do whatever it takes** to bring you some of the most fascinating images of our Solar System and beyond.  If staying up until 2:30 a.m. is necessary, we’ll* do it!

This early morning view of two planets and the Moon was simply too good to miss, so yes, I stayed up to at least see it when the Moon had risen high in the South.  Jupiter and then Saturn followed.  Frankly it was pretty cool, and I can’t wait for what views will top this one in the ensuing months.

If I believed in astrology, I would probably think this planetary configuration was the harbinger of a great sign or omen.  Fortunately, my only reaction was to enjoy the view, and to run back inside to get my phone and capture what I could of the scene.

The image is heavily edited, taken from a source iPhone NightCap TIF.  I tried my best to compensate for the Moon’s brightness, the area’s light pollution, and keeping especially Saturn visible.  The end result is a somewhat blurry mess, but hopefully the framing gives proportion as to what the sky looked like.  And this does give a proper perspective of the light pollution in my area, from the front lights to the general blandness of the sky (though the Moon was largely a contributing factor).

On a related note, on the previous night, around 9:05 p.m. local time, I spotted Mercury for the first time this year.  The sky was about as clear as it could be.  With Dusk still settling, I used Pollux and Castor as the easy guide stars to look down, with my binoculars, to find Mercury.  Once found this way, I was able to make the planet out, barely, with the naked eye.  Through the binoculars I also spotted, still in Dusk, a faint star to the right of Mercury, which according to Stellarium was likely the 3.05 magnitude Mebsuta.

Three planets spotted within six hours.  My planet viewing season has begun!

* I
** Restrictions and conditions apply

The Shape of Things to Come – Jupiter and Saturn

Saturn (left) and Jupiter (right). Click to see full-sized image.

September 24th, 2019, 07:50 p.m. local time

This is a very exciting post, at least for me.  It’s the first time on my blog that I have a picture of Jupiter and Saturn together!

I had to do some travelling today, and as I disembarked from a late train, I looked to the South to see a clear (albeit light polluted) sky an hour past Sunset.  I knew immediately what I wanted to find: our Solar System’s fifth and sixth planets!

I haven’t been tracking either for the last few weeks, so I was worried Jupiter was already too far towards the horizon by now.  But I was pleasantly surprised to find it still firmly in the Southwest.  And with Saturn almost due South, I grabbed my phone from its sturdy belt pouch, and began taking pictures of the night sky.

We’re going to be talking about Jupiter and Saturn as they approach each other (as seen from Earth) over the next year.  For now, though, I will only note that Saturn is currently residing by the constellation Sagittarius (again, as seen from Earth).  Scott’s Sky Watch! recently posted a nice drawing showing essentially the above image (minus the Moon, which is now a Waning Crescent rising after midnight).  Plus, it shows the outline of Sagittarius.  Go check it out!

For the sake of the explicit, here is the picture again, with the planets labeled:

Click to see full-sized image.

Imaging Jupiter – How Many Frames to Stack?

This post is a bit delayed as I went back and forth on how to frame it (no pun intended), and which topics specifically to cover, because I would like to start showing more of how I create my final planetary images.

My initial thought was to do a grand all-in-one post on the entire process in detail from start to finish.  But I ultimately decided that would be a bore to read.  Instead, I decided to go with explaining specific units of the process in shorter and hopefully concise explanations.

Today I will focus stacking frames.  Planetary (as well as deep sky) imaging requires stacking multiple picture frames, either actual still images or the frames from a video.  Because all of these objects are extremely far away, no one single picture can capture enough light to make a full picture.  The targets are too small and the number of photons impacted onto any imaging sensor is minuscule.  But…if enough single frames are combined in the right way, you can get a semblance recognition of a planet, a star, a nebula, or even another galaxy.

For comparisons, here on Earth, when you shoot a picture, of any type, there are more than enough photons to fill that picture no matter the mode of imaging.  Your target is very close to you, measured in feet (meters) or miles (kilometers), it doesn’t matter; deficiency of photons is never going to be a problem..  The same holds true essentially for the Moon as well, on a cosmological scale.  In the grand scheme of the Universe, our moon is a stone’s throw from us, ridiculously close, reflecting many photons from a few hundred thousand miles/kilometers away.  With the right magnification (a telescope) you can take easy pictures of the Moon with any camera.

On August 23rd I set up my Dobonsian telescope to look at and photograph Jupiter.  With a clear sky, I used my normal telescope and camera configuration:

  • Telescope: Dobsonian reflector 254mm / 10″ (homemade)
  • Camera: Canon EOS Rebel SL3
  • Barlow: TeleVue Powermate x5 1.25″
  • Filter: Baader Neodymium 1.25″
  • Canon T ring and adapter

The computer program post-processing sequence goes PIPP -> Autostakkert -> Registax.  Selection of the frames to stack is in the application Autostakkert.

Outside at night, I tried several different ISO and exposure combos.  After reviewing all of them, I decided that ISO 1600 and exposure 1/60 seconds was the best that night.

In Autostakkert, you can choose a set number of frames to stack, or a percentage.  I always go with a percentage:

You may ask, how does Autostakkert know which frames are best?  You have to choose a reference frame, i.e. pick which one you think is the best approximation to what the actual image should be.  This is very much art and not science.  Here is an example of a completely raw Autostakkert frame for inspection:

Obviously, a lot of picture data is missing from the above image.  But it does represent a single source video frame taken from my camera at the telescope.

Once I decided that ISO 1600 and exp 1/60 was the best, I went back to Autostakkert and re-ran the process with different stack percentages.  I used 15, 30, 40, 60, and 85 percents.

Here are the finished (non-touched-up) images from Registax:

Best 15 percent of frames.

Best 30 percent of frames.

Best 40 percent of frames.

Best 60 percent of frames.

Best 85 percent of frames.

Typically, for three ~25 second videos, I get about 4500 frames of video.  So, for example, the best 30% would be a stacking of 1,350 frames.

My observations on the different percentage stacks are:

  • At 15%, the image looks bit grainy, since it is probably still missing some image data to fill the grains in with.
  • 30% and 40% are the best, and I have a difficult time deciding which is better.  But in the end I decided that 30% looked slightly more clear.
  • 60% and 85% are a tad blurry, and that is due to Jupiter’s fast rotation starting to manifest itself.  A “best” frame could be at the beginning of the 3-image set or it could be at the very end of the 90 seconds, or anywhere in between.  But it’s safe to assume the distribution is roughly normal across the 90 seconds.

So once I had my best ISO, exposure, and percentage of frames stacked, I did some minor post-process editing in PaintShop Pro to (hopefully) sharpen the final picture and (hopefully) reduce noise:

Jupiter on August 23rd, 2019

New Jupiter Options


August 9th, 2019, 9:45 p.m. local time

This was the first test of my new, mighty Canon EOS Rebel SL3.  It operates very similarly to the SL1.  I had to go into the menu options to disable the “fluff” to get back to the bare-bones menus.  Once I did this, the SL3’s menu interface was near-identical to the SL1 interface that I am very familiar with.

The first benefit I noted was the rotatable viewfinder.  When looking down the viewfinder sights of my Dobsonian reflector, I was able to aim the LCD back towards the rear of the telescope.  This saved time and the normal frustration of finding the target in the viewfinder and then having to stand upright again near the front of the scope to make “blind” adjustments to pinpoint the target.

With the SL1, I settled on an ISO of 1600 and exposure of 1/125 for Jupiter.  For this session, I kept with those settings, though I did try HD videos at 30fps and 60fps.  In later analysis, the 60fps final imaging was slightly better.

Above is the best post-processed result from the night.  You can see the festoons and marginal detail in the cloud bands.  I feel this compares with the better range of images I produced in the past few years with the SL1.

For reasons I will get into when I post about Saturn from the same night, I feel this camera can produce better, likely by increasing the ISO above 1600, increasing the exposure, or both.  I will need to experiment with these settings in my next session.

With the SL1, I had been stacking the best 60% frames, but for this session, I noticed that 30% looked better.  Whether this was due to the new camera (needing less frames for a clearer final image), or a quirk of the night’s conditions, I can’t say.

Another benefit, I believe, of the new camera is that I can finally process a Drizzle in Autostakkert.  I have rarely mentioned the Drizzle feature, but have a hunch I will be experimenting with it more.  All it means is that when the best video frames are stacked into the initial raw image, the picture is blown up by three times.

Drizzle can help to see detail if your base images are in good focus.  Here is my test Drizzle image, processed at three times the size of the normal image above.  Its size is reduced to fit the confines of the blog, but you can click on it to see the full image.  And it is not a coincidence that both images in this post, the normal and the Drizzle, may appear exactly the same size, as I reduced this one to show at 400×400 pixels like the normal one above.

“Drizzle” Jupiter. Click for full-sized image.

Summary of my equipment, settings, and software used:

  • Telescope: Dobsonian reflector 254mm / 10″ (homemade)
  • Camera: Canon EOS Rebel SL3
  • Barlow: TeleVue Powermate x5 1.25″
  • Filter: Baader Neodymium 1.25″
  • Canon T ring and adapter
  • Relevant camera settings:
    • ISO 1600
    • Exposure: 125
    • HD video at 60fps
    • Created from three videos of about 25s each, best 30% of frames
  • Software for post-processing:
    • PIPP
    • Autostakkert
    • Registax 6
    • PaintShop Pro for final minor touchups

Heading for Jupiter

From left to right: Moon, Jupiter, Antares, telescope.

August 9th, 2019, 9:30 p.m. local time

Getting my telescope ready to look at Jupiter tonight, with two of the brightest objects in the night sky paired close.

Fixing Jupiter

Jupiter on August 1st, 2019.

I mentioned previously that on the evening I captured the ISS fly overhead, I also got the telescope out to see Jupiter.  It was a clear night with no Moon, very comfortable for early August, and most importantly, and strangely, hardly any insects to annoy me.

(And in case you are wondering, I didn’t want to wait for Saturn, as it would have been another 1-2 hours before it cleared the trees blocking my backyard’s Southeast view.  School night/work night and all that…)

I only took a few sets of videos.  None of them had great focus.  Of the three sets of videos (three ~25s videos each spanning no more than 90 seconds total due to Jupiter’s fast rotation), I chose the middle set.  But then I thought, what if I chose only two of the videos instead of the full three?  That might reduce some of the rotation blur, at the cost of detail.

Above is the result of two stacked videos.  And for reference, I also tried processing just one 25s video, but it was much too grainy.  Plus, I experimented with stacking the best 30%, 60%, and 80% of frames, and in this case, 80% looked best (I usually stack 60%).  The magic of planetary imaging is to find that sweet spot on a given night of clear skies, focus, and number of good frames to stack.

Summary of my equipment, settings, and software used:

  • Telescope: Dobsonian reflector 254mm / 10″ (homemade)
  • Camera: Canon EOS Rebel SL1
  • Barlow: TeleVue Powermate x5 1.25″
  • Filter: Baader Neodymium 1.25″
  • Canon T ring and adapter
  • Relevant camera settings:
    • ISO 1600
    • Exposure: 125
    • Created from two videos of about 25s each, best 80% of frames
  • Software for post-processing:
    • PIPP
    • Autostakkert
    • Registax 6
    • PaintShop Pro for final minor touchups

The Importance of Taking Notes

Jupiter on the evening of Monday, July 8th, 2019, through my 254mm Dobsonian telescope.

I began taking copious notes when I entered high school.  I recall, in particular, my history class from that first year.  The several-hundred page spiral notebook filled up, week after week as I listened to the instructor recall the highlights of Western Civilization, from the early formations of Rome up to the monarchies and rise of the nation states in the 19th century.  It became almost a little game for me, to see how much of each lecture I could transcribe, even though much of that information wouldn’t find its ways onto the quizzes and exams.  I felt like the keeper of a sacred knowledge in accordance from the one who professed it.  A sort of happenstance holy book emerged that I couldn’t easily discard at the end of the school year, unlike the largely unfilled notebooks from my other classes.

Notetaking garnered even more importance when I entered college, as I attempted to keep all of the calculus, physics, differential equations, and engineering concepts straight in my head.  These produced, sometimes, even larger sets of writings in the form of official homework assignments.  Using up spiral notebooks and loose-leaf paper was the norm back then, and I still remember how my wrist and hand would ache.

Now in 20+ year hindsight of my humble and narrow career, I see that notetaking was necessary at times, but not at others.  It was certainly more relevant in my early days, fresh out of college.  That was still the pre-Outlook era, and email seemed more an offbeat frill than the mundane requirement it is today.  My work notes and scribbles are far from timeless.  Most spoil quickly and are no longer useful even after just a few months.

When I took up my astronomy hobby in earnest nearly a half decade ago, I held an enthusiasm for keeping logs of my activities.  Particularly, I recorded in detail my photography sessions in the hopes of learning from prior attempts.  My little journal book has been invaluable when I restart taking pictures of the Moon and planets.  What exposure and ISO worked best last year for Jupiter?  Without my journal, I may have given up as it would have become too onerous a task to rebuild and reimagine how to take these photographs at seasonal and annual intervals.

My astrophotography journal came in very handy this week as I put my telescope and camera and lenses back into full service.  Today’s highlight from those evening sessions in Jupiter.  I timed the above picture knowing that the Great Red Spot was visible for several hours on Monday night.

Comparing this to several of my prior Jupiter images, notably from 2018, I am very please with the results.  Always keep in mind, until further notice, that my telescopes are not intended for imaging and my camera is not designed for astrophotography.  It is a hassle to manually nudge my Dobsonian just enough every 30 seconds without completely losing bearing on my current target, but it’s still fun and the results are usually decent enough to share.

Summary of my equipment, settings, and software used:

  • Telescope: Dobsonian reflector 254mm / 10″ (homemade)
  • Camera: Canon EOS Rebel SL1
  • Barlow: TeleVue Powermate x5 1.25″
  • Filter: Baader Neodymium 1.25″
  • Canon T ring and adapter
  • Relevant camera settings:
    • ISO 1600
    • Exposure: 125
    • Created five sets of three videos 24-29 seconds each, refocusing after each set
  • Software for post-processing:
    • PIPP
    • Autostakkert
    • Registax 6
    • PaintShop Pro for final minor touchups

Relative Planets

Evenings of July 6th through July 8th, 2018

The weather was amazing this weekend, especially for early July.  Clear skies, no humidity, and bugs only became a problem on the final night.

On Friday evening I took another set of Jupiter pictures.  These are not shown, as the following day’s images were far superior.

After Friday’s Jupiter session, I kept the telescope out after midnight, so technically on Saturday, to image Saturn for the first time this year.  As always, I have to wait for the planets to clear trees to the Southeast.  Since Saturn is now a few weeks past opposition, I get a clear few of the planet shortly after midnight.

For Saturn, I checked my written log for the settings I used last year (ISO 3200 and 100 exposure).  These, according to my log, gave me my best results.  But thinking I could do better based on my recent Jupiter work, I decided to try ISOs at 1600 and 800 and exposures of 60 and 30, respectively.  Lower ISO means less noise.  The results were not too bad, but I think the 3200/100 settings are still the best, and will try those next time.

On Saturday night, I took what I think may be my best Jupiter yet.  The finder focus on my first attempt was near perfect, if not perfect.  Look at the cloud band detail!  I only wish the Great Red Spot was facing us more at the time.  You can also see Io next to the GRS.

Then on Sunday I dragged my big telescope to my front lawn to capture Venus setting in the West.  This is the first time I did that.  The results were much better than I expected.  You cannot get much from Venus beyond its general shape.

What is neat about lining all three images side-by-side is that they were taken with the same telescope and same equipment setup, so you get a great sense of their relative sizes as seen from Earth.  Venus is noticeably smaller even though it is the closest to Earth and approximately the same size as Earth.  Right now, Venus is just over 90 million miles (145 million km) away.  Jupiter is about 450 million miles (724 million km) past, and Saturn is 840 million miles (1350 million km) from us.

What I should have done was take an image of a star, to show its relative size as well.  Next time!

Equipment used this weekend:

  • 254mm homemade Dobsonian
  • Canon EOS at prime focus
  • TeleVue x5 Barlow
  • Neodymium filter