Leveraging Starlight for Sharpening Planets

The field of digital planetary imaging is where art meets science, particularly in post-processing. After using our preferred tools to distill a video of several thousand frames into a stacked and aligned image, there is still much work to do. We need to refine it into a sharpened view of the target before applying some tweaks in a program like Photoshop. To achieve that sharpened image, we have two techniques at our disposal: wavelet sharpening and deconvolution.

Wavelet sharpening is a key feature of the freeware application Registax6, a staple of planetary imagers for many years. The author of the software, Cor Berrevoets, has not issued an update to the venerable program since 2011. He has, however, created a successor in the form of another freeware application called waveSharp. Both of these tools decompose the selected image into layers - from large-scale components of the image to fine scale. By adjusting the sliders, you can selectively enhance these aspects of your image. The finer scale adjustments must be done with a light touch to avoid introducing significant noise to the final result. Fortunately, one can combat the noise by suppressing the finer scale adjustment.

The ability to apply deconvolution is appearing in more tools for the planetary imager. One excellent new addition is the Lucky Stack Worker (LSW) freeware application (a video by the author, Wilco Kasteleijn, is on the ALPO channel). Another is AstroSurface, an application with extensive filters and functions for not only the planetary imager but the deep sky enthusiast as well.

So, what is deconvolution? In brief, it is using a contemporary representation of an Airy disk to help recover detail lost through atmospheric turbulence, soft focus, or optical issues. Under perfect conditions, when examining a moderately bright star, you would expect to see a small disk with diffraction rings emanating from it, known as its Point Spread Function (PSF). The interface on the LSW has two checkboxes - one for "Deconvolve" and one for "Sharpen" (i.e., wavelet sharpening). If we select the Deconvolve and select the "bullseye" adjacent to it, we see that LSW is offering us a synthetic PSF with sliders to allow us to adjust it.

Impacts when adjusting the Seeing Index slider

You could take a few minutes before or after your imaging run to inspect a nearby star and make a note of its Airy disk appearance to emulate it in the synthetic version. But why not record an image to capture the PSF for that particular imaging session? This is exactly the sort of thing that Wilco Kasteleijn advocates in the LSW manual and references a nice article by Marco Lorenzi on how to do this.

A couple of nights ago, Astropheric was displaying that the seeing would be "average" with temperatures in the 40s, so it was an opportunity to try this technique and maybe gain some experience acquiring a PSF image to leverage in my processing. Like a deep sky flat frame, the PSF image should be taken with the same imaging setup and without pointing the telescope too far from the target.

My first attempt using a star near Jupiter did not yield results, as it ended up being too faint and requiring a longer exposure. That, in turn, blurred the Airy disk by its scintillation. For Mars, I targeted a brighter star and had more success with a frames-per-second rate nearing 100. Even so, it is challenging to get it right; in retrospect, I should have lowered the gain further to avoid "blowing out" the Airy disk.

The PSF image taken during the imaging run

So, here are the results! Even with only a fair PSF image processed by Autostakkert, the LSW did a nice job of recovering the details from what turned out to be sub-par seeing. Applying sharpening and denoising to the image resulted in a reasonable, if not admirable, image showing albedo features, the polar cap, and likely cloud features.

To me, this technique of capturing a PSF image as part of the Lucky Imaging session holds great promise. As a final note, here is a Copilot-assisted comparison of how these two techniques help us achieve fantastic planetary images.

Chasing Planets: January's Observations and Challenges

The media has been hawking the auspicious "planetary parade" that allows an observer to see 6 planets during frosty January evenings. Of course two of those (Uranus and Neptune) are not naked eye objects. I do not mind articles that generate interest in our hobby, but my fear is always the "over promising and under deliver" risk.

However, January was indeed a fun month for us planet observers. Mars was occulted by the nearly Full Moon on the evening of the 13^th, and then two days later came to opposition for this apparition. Jupiter was positioned well and decided to throw a major eruption amid its North Tropical Zone southern jet stream on January 10^th, garnering a lot of attention. Venus also ascended the Zodiac after lying close to the southwestern horizon most of its current evening apparition, reaching greatest elongation on the 10^th heading for its highest altitude in the western sky on February 2^nd. The only downside has been the weather with classic winter turbulent seeing amid very cold temps.

Mars Occultation

The skies were clear but quite cold for the occultation of Mars. I set up the 10" Cyrus telescope and verified its collimation. The Moon served as a convenient focus target as I set up about 20 minutes before the scheduled disappearance. I knew that the difference in brightness would be a challenge and thought I'd have time to fiddle with the gain setting right before the occultation, but it happened so fast that I really did not get a great capture with the Moon very overexposed. Still, it was a very cool event to watch the Moon relentlessly approach the red orb and cover it up with about 30 seconds.

The Moon ready to cover Mars

January 17th Session

The evening of the 17th was predicted to have average seeing and temperature right around the freezing mark, which is fairly good for this region in winter. I again set the Cyrus scope out early to cool and verified its collimation. As Venus emerged from encroaching twilight I set to work on capturing our sister planet. 

Starting with the Deep Red filter (642+nm) and no Barlow, Venus provided a bright target upon which to focus. Doing a 5 minute capture resulted in a nice image, showing the planet past dichotomy and a common cue-ball appearance. I have yet to truly discern any cloud details in IR light.

Swapping out the Deep Red filter for an IR-block and UV set, I retargeted the planet and adjusted the settings to bring up the brightness in the fainter UV light. I could make out even on the on-screen image that there was uneven brightness in the sunlight reflecting off the Venusian cloud tops.

Processing produced a nice greyscale image with a some cloud structure. Interestingly, a well defined cusp cap was not really seen, although you might argue one was around the south pole region. This is somewhat in agreement with the UV Venus images I have been seeing submitted to the ALPO for the current evening apparition; cusp caps are not as prominent as I believe they were during the last apparition.

By now Saturn was visible in the deepening twilight, close and to the left of Venus. I figured why not give it one last capture since the upcoming mid-March solar conjunction and my obstructed western horizon meant it would soon be inaccessible. I added the Barlow back into the imaging path and returned to the Deep Red filter. Seeing was not very good, and the rings had closed up again compared to a few months ago. I had enough juice in the laptop for two 2-minute captures, resulting in a sub-par image where it is hard to even detect the globe's shadow being cast against the rings. Au revoir Saturn - until we meet again in the late spring!

Getting the AC adapter hooked up to the laptop I next swung over to Jupiter. My hopes were to get multiple captures into the evening if the weather held, recording not only the very recent North Tropical Zone southern jet stream eruption but also that continually expanding disturbance in the South Equatorial Belt that started back in November.

The seeing ended up being fairly good over the course of about 5 hours, allowing me to capture a lot of interesting features, including that NTrZ outbreak. As we began to close in on midnight the gods conspired to end my run as the cirrus clouds began to thicken and the tracking on the Celestron mount suddenly had a stall (it is always amazing how quickly the planet exits the frame when this happens). Rather than fight to recenter and continue amid the deteriorating seeing and transparency I decided to wrap things up on Jupiter.

In the middle of my Jupiter captures I had to take a break due to the location of the planet. When an object is high and near the meridian, the Cyrus telescope tube runs up against one of the tripod legs. The resolution would be to raise the tube up off the saddle, somewhat like extending with a pier. But that would be a lot of effort and so is not likely to happen in the near future (if at all). 

But rather than waste the time I opted to do a run on Mars which had just passed opposition a few days earlier. While at only about 13" in size the disk was large enough to take in some nice albedo features such as Syrtis Major setting and Sinus Sabaeus and Sinus Meridiani on the central meridian. The NPC was also a brilliant white and was a good feature to leverage in trying to get the best possible focus. Hopefully I will get in a few more sessions with Mars for this apparition, but it's going to shrink in size quickly now that it is past opposition.

While I did not achieve all my goals for the evening (I missed seeing the SEB disturbance on Jupiter), it was quite a good night for the middle of January. It reflects why planetary observing provides such a rich experience for the amateur astronomer.

Not Feeling Lucky

"Diligence is the mother of good luck." - Ben Franklin

I guess it's been the better part of a decade since I first encountered the term "lucky imaging" that is used in amateur astronomy to characterize the technique of stacking and enhancing video frames to produce the stunning planetary, lunar, and solar images that we see so often today. The moniker derives from the fact that we are able to extract those brief, "lucky" moments when the seeing has steadied for a split second to create a photo that reveals details the eye could never behold. Indeed, not just our eyes, but those of us old enough to have tried capture using film greatly appreciate the superior results (and in many ways the simplicity) of using this digital video approach.

While the term has a rational basis for its origin, I have to confess it has never sat quite right with me. Using it connotates that I pointed my telescope at my target, yelled "action!" and hoped for the best. If the imaging gods smiled on me then I was rewarded with a detailed image of  Mars revealing Olympus Mons or kilometer-sized craters on the floor Plato. If they did not I was left with a fuzzy outcome that no amount of post-processing could salvage. Better luck next time kid! 

Of course, any serious solar system imager knows that aside from decent seeing, luck is a rather small component of creating a nice capture of your target. There is the research into what equipment to use and the financial investment in acquiring it. That equipment then often needs a knowledgeable and skilled hand for optical alignment (collimation) to wring every last sub-arcsecond detail from our quarry. Once that is checked one needs to engage in a successful polar alignment to enable tracking of the object at high magnification. If an Atmospheric Distortion Corrector (ADC) in your imaging train then that, too, must be adjusted throughout the imaging session to combat the subtle smearing that occurs when light travels through our home planet's blanket of air. 

One of the biggest challenges is achieving a sharp focus. "Lucky" imagers do not get the benefit of a Bahtinov mask to provide the assurance that they have a crisp image. The user must study the image on the screen to identify a high-contrast feature to zero in on and then twiddle the knob incrementally back and forth while evaluating the outcome after each minute adjustment. If being done by hand that means waiting a few moments after each tweak for the target to stop dancing around the field. (Those of us who have outfitted our scope with an electronic focuser would never part with it!) 

Once collimated, polar aligned, and focused it's on to setting up the gain and exposure in the software's capture interface. Having the fastest possible shutter speed while holding the graininess of the capture at bay is another balancing act that the imager has to perform. Finally, we're ready to capture some video!

With gigabytes of data safely stored on the hard drive you're halfway home. Next comes the post-processing effort where we transform those thousands of frames into a single thing of beauty. But between those two points lies a bevy of software products to perform that magical massage, and the time to learn how to use them. One of the most critical stages, the wavelet sharpening, is part science but very heavy on art. Here the observer must use their skills to sharpen the stacked outcome in such a way as to provide the clearest view that does not introduce artifacts into the final product. Only after all this effort based upon investment in equipment, study, and experience does the reward of a detailed photograph of a member of the solar system emerge. 

Lucky? Really? 

I may be tilting at windmills here, but I am launching a campaign to retire the "lucky imaging" description for a more appropriate acronym. I asked the question on the Cloudy Nights forum and got some interesting (and humorous!) suggestions along with pretty universal support to call our technique something else. Some of them contained the word "planetary" in the acronym, which would describe most of my personal effort but snub the amazing work done by Solar and Lunar imagers. After collecting descriptive terms and jockeying them around I think I finally have the replacement acronym:

Solar, Planetary, and Lunar Imaging Capture & Enhancement (SPLICE)

Not only does it cover the targets for which we most often apply the technique, the "splice" has a slight double entendre in that in many ways that is at the heart of what we do - gather the best parts of our movie and then splice them together for our finished product. 

Coming up with a suitable acronym is certainly the easier part of this effort. The real challenge will be to get our favorite print publications (and other influencers such as podcasters and YouTube creators) to adopt it. It's up to us to ask them to remove "lucky imaging" from the amateur astronomy lexicon!

The Pixel Sweet Spot

Earlier this week the forecast was for an evening of average to perhaps better than average seeing with cold (but not biting) temps. I rolled out the scope a little before sunset to begin cooling and got things ready - with Jupiter just past quadrature it is always going to be highest in the sky as soon as it becomes visible. 

I did the routine alignment, collimation check, and finder alignment before finally popping in the ZWO camera. Activating the camera I was greeted by a strange sight - an emerald green Jupiter. At first I thought maybe a Debayer setting was off in the capture interface but soon noticed that the histogram was not registering in blue or red, only green. I rebooted the laptop hoping maybe that would restore things, but no luck. I brought up a different capture application, but it, too, sported a green globe.

Rather than admit defeat I located my retired Imaging Source camera and popped it into the Barlow. The view and histogram confirmed that we were back to getting a color image, but I immediately was struck by how much smaller the image appeared to be. Hmm - what was that about?

It turns out that my older camera, a DFK21AU042, has a pixel size of 5.6µ whereas my ASI178MC has a size of less than half that, checking in at 2.4µ. The formula for calculating how much sky each pixel registers for your setup is as follows:

  (Pixel Size/Telescope Focal Length) * 206.265  

For my setup using a 2.5x Barlow that becomes:

DFK21AU042 = 0.31"

ASI178MC = 0.13"

The theoretical ideal for planetary imaging for under average seeing conditions is around 0.15" per pixel (Note that this is different than DSO imaging, where the average is about 1-2" per pixel). Clearly, my ZWO camera is a lot closer to the mark, and the better thing to have done would have been to stop and swap out my 2.5x Barlow for my 4x one to get a little lower arc-second/pixel value. But the window of calm seeing that we often get shortly after sundown wouldn't allow that, so I forged ahead.

Below are comparative images taken about a week apart of roughly the same Jovian longitude. It is pretty obvious from it that we lose resolution in the image acquired using the DFK21AU042 camera.

Is the image from the older camera terrible? No, hardly. We can still make out details like Oval BA and anti-cyclone storm A1 - something that was unheard of using film a few decades ago. But in astronomy, and in planetary imaging in particular, it is all about getting all the parameters as ideal as possible so that you can capture all the details available given the seeing conditions. Hopefully I get my ZWO camera fixed, but in the meantime I know from experience now to at least break out the 4x Barlow to try to get closer to that desired arc-second/pixel value.

Putting It to the Test

One of the many sections of ALPO^[1] is the Online section, of which I’m an assistant coordinator. While currently this means I’m focused on helping to maintain the organization’s website and post observations to the galleries, I think there can be more to the section.

Born as the “computer” section in response to the PC revolution and its impact on our hobby, the original aim was more towards what sort of software was available to assist the amateur planetary observer. To me, this has more relevance than ever given how integral software has become in processing most observations today.

There are many competing products out there that one can choose to align, stack, sharpen, and tweak their video capture into a valuable image that documents the state of an astronomical body for a given point in time. Less available to the amateur observer is a sense of how the software works or what approach is preferred (or should be avoided). Often the individual approaches it as a bit of a black art, playing with settings in the interface and seeing if the outcome is better or worse. While the learning curve is perhaps not as steep as with something like PixInsight for our deep sky imaging brethren, there are still many nagging questions when doing a planetary imaging workflow – “Am I doing this right?”

This is where I believe that the ALPO Online section has a role to play harking back to our roots as the “technology” arm of the organization by conducting studies to shed light on common questions. As an example, when setting alignment points on an image in preparation for alignment & stacking, what size works best? How important is that? What is the current theory on it, and does that theory hold when tested? Questions such as this are not just academic, their answers can impact the quality of our output.

With all this as background I’m announcing an effort to tackle some of these software setting questions. Lifting a page from the Zooniverse folks, my idea is to generate a set of images where, to the best of my ability, all parameters are the same except for one and then invite the amateur community to score them. With a sufficient number of evaluations, it should be possible to make a statement (and perhaps a recommendation) on the optimal setting to use when processing your video into a final image.

I have defined my first inquiry and worked up a set of images to use in the test. The posit is that when processing a video taken under only fair seeing it is better to use larger alignment points, whereas a capture under very good seeing benefits from smaller sized alignment points. The theory is well explained by Christophe Pellier in Chapter 7 of his excellent book Planetary Astronomy:

“An AP is defined by small boxes and the alignment will be done based on the details that are present inside of it. If the image is noisy and with low contrast, a size that is too small will prevent the software from performing a comparison because of a lack of detail found in some of these boxes. On the other hand, if there is considerable detail present a smaller size AP will increase the accuracy of the alignment.”

Perhaps I am tilting at windmills here in thinking that I’ll get enough participation, who knows? I’m hoping to be able to not just confirm the theory but to also offer some qualitative assessment of its impact on one’s resulting image. If you would like to participate in reviewing the six sets of images, please visit my new ALPO Research & Investigation web page that I am hosting on my personal website until such time that it proves viable and suitable for deployment on the official ALPO website. And thank you in advance for your time if you do decide to participate!

---

^[1] Association of Lunar and Planetary Observers

More Than Meets the Eye

Sept 20-21, 2022  

While prepping for my HAL talk last month I stumbled across the fact that the Astronomical League has a Jupiter Observing program among its offerings. It's a program whose objectives I've certainly met over the years, but thought it would be fun to officially claim the prize. 

One task is to collect a series of observations on the 4 bright Galilean moons and interpret your data to characterize the moons and their orbits. You need a couple of sessions spanning over two hours, and this evening's clear skies (and an added bonus of a Ganymede transit) was a nice opportunity to meet some of the program's requirements. I decided to use the 80mm Vixen refractor since it is easier to set up and more than adequate for recording the bright moons.

By 10:30 I had Jupiter centered in the eyepiece. Ganymede's large and stark shadow is not hard at all to pick up on, even in this small aperture. While I could have simply sketch the moon positions, I opted for a set of video images at 30 minute intervals as a better approach. 

Galilean Moons, with Ganymede in Transit

When I finished the first capture I did a quick processing to see what I had. I was actually a little surprised at the detail on the planet using such a small aperture. It led me to wonder just how much detail could I get using the Vixen if I tried? 

Since I needed to wait a half hour to make my next capture I decided to explore the question. I popped in the Meade 2x short Barlow and brought the Region of Interest (ROI) as tight as I could. This smaller capture area allowed the frames-per-second rate to go from 96 to 286, increasing the chances of leveraging those microseconds of steady seeing into a nice photo.

Next day I set to work running the video capture through my workflow - PIPP, Autostakkert3!, and Registax6 to produce a final image. Although the details are puny compared to what the 10" Cyrus reflector produces, they are pretty amazing given the aperture. Not only do we get the major bands, but features such as festoons in the NEB, Ganymede's disk as it begins to egress, and even Oval BA can be clearly identified in the tiny image. 

Would one suggest an 80mm refractor as a good instrument for planetary exploration? Not really - but it clearly has a lot more to offer compared to what you'll see behind the eyepiece when you team it up with computer assisted planetary imaging. Visually it takes a little effort for me to discern Oval BA using the 10" with a suitable filter. Snaring it in a capture using a telescope with 3 inches of aperture is really quite a testimony to the high-contrast quality that refractors offer as well as the power of using the lucky imaging technique. If you use a similar scope as your main tool for exploring the night sky you might consider adding on a planetary video camera and discover for yourself the enjoyment of capturing features that you'll likely never see visually.

Attempting ADC

 I've attended a couple of sessions within the last year led by renown planetary imagers (Damien Peach, Agapios Elia) in pursuit of what I can do to refine my setup. One thing that both mentioned rather high up on their list was using an Atmospheric Dispersion Corrector (ADC) in the imaging train. The premise is that the atmosphere bends blue light differently than red light, causing a slight smearing of the "white" light we get at the eyepiece. An ADC, which is a set of adjustable prisms, allows you to correct the dispersion, yielding a sharper image. 

I had hesitated on acquiring one, in part because both individuals use large SCT units for their imaging - would a Newtonian benefit? Second, I had assumed (incorrectly) that the amount of smearing would be minimal once the planet got above 30° (see this). And finally, the Autostakkert software supposedly performs a correction for this when stacking.

Autostakkert "RGB Align"

I ended up convinced that it might be helpful so I got the ZWO model which was a past Sky & Telescope "hot product" award winner. The unit arrived about a week after ordering it, and as forewarned by my research, there were no instructions on how to use it. Fortunately other brave souls have sorted it all out and been kind enough to post video tutorials.

The unit is placed between your Barlow and the imaging camera. There are two steps for having it correct the atmospheric distortion:

1. Use the bubble level to ensure that the unit is parallel with the horizon. That will obviously fall out of order as the evening progresses and your scope tracks the planet across the sky, so re-doing this step every half hour or so may be needed.
2. Adjust the two silver levers (on right in picture) in equal but opposite directions until you can no longer detect color fringing 

It is that last step that can be tricky. One approach recommended by Martin Lewis is to overexpose the planet on your screen to make the fringing more obvious. You can then iteratively adjust the levers until the fringing is minimal (or at least you are unable to say which side is reddish one and the other bluish). Many of the imaging capture programs (e.g., FireCapture, ASI Capture) also have a utility to help assess your alignment. In general, when the circles overlap then you have achieved merging the spectrum back into white light. But given how wildly the two circles will bounce around on the screen it is still a bit of a swag. 

Performing ADC Alignment with Jupiter

This past week I decided to give it a go and placed the unit between Barlow and camera. Given the height of my set up, I had to use the step ladder to reach up to perform the leveling and then to gradually spread the levers, constantly referencing the laptop screen to see the impact. Of course another trick is to do it gently enough to not knock the planet out of the field of view. After about 5 minutes I felt the bouncing circles were are concentric as I might achieve. I did a focus and then started a couple of captures.

Sadly, what I noticed about 20 minutes in was that my focus was a bit soft. Looking at the focuser read out I noticed I was racked fully in due to the extra back space the ADC introduced. And sure enough, the actual focus point was just a tad further in. No amount of ADC will substitute for mushy focus, so I pulled it off and resumed imaging with a sharp focus. My task now will be to remove one of the spacers from the Moonlight focuser so that we can get to that focus point with the ADC in place.

Will it all be worth it? Hard to say, but given the feedback from well respected imagers I certainly am committed to finding out. And empirically it makes sense to try to correct this dispersion as the image is captured rather than to depend in post-processing algorithms to fully compensate for the effect. That's the game now - incremental improvement wherever I can achieve it.

Jupiter without ADC - can I tease out more with an ADC?

A Camera Upgrade

Like most enthusiastic amateur astronomers I have a long list of gadgets and upgrades I'd like to acquire. But until I hit the lottery I have to prioritize these things. High on the list has been to replace my nearly ten years old planetary video camera. An ImagingSource DFK21AU042 color camera, it has served well and still can acquire good images of the brighter planets. But with a maximum frames per second (fps) of 60 (and 30 for dimmer Saturn), I feel the need for speed.

Based on what I've seen posting images to the ALPO gallery as well as some Internet research, I concluded that a ZWO camera would be a reasonable brand to go with. Another relatively easy decision was to get a color camera again. A monochrome, using R-B-G filters to create a final image, certainly offers better results, but it significantly increases the amount of time to acquire and process the files. And of course there is the several hundred dollars of investment in a filter wheel and those filters. I need to keep it a bit simpler, at least for now.

My other two primary criteria were a smaller pixel size and the ability to achieve a fps rate above 60. Fortunately ZWO does offer a nice comparison grid to see the differences among their many products. I finally settled on the ASI178MC with its 2.4µm pixel size (less than half the size in my existing camera) and potential fps greater than 100. I tried initially to order from distributors in the US but everyone was back-ordered, whereas ordering from ZWO directly I had my camera in about a week.

The first clear night (surprisingly I did not get the month of clouds curse that often accompanies new equipment purchases) I targeted Jupiter and Saturn with the Cyrus 10" reflector and the ASI178. FireCapture immediately recognized the camera, but I was stymied in getting the frame rate to exceed 60 fps, even with cropping the region of interest (ROI). But even so I was happy to see I could image Saturn at that rate which my old camera never achieved.

Saturn using the ASI178

A little more research provided some insight as to what might have been blocking the higher frame rates. The camera can run in either 14 bit or 11 bit color modes. The smaller color palette of the 11 bit allows a higher rate - but there was no way (that I could find at least) to specify the bit level using FireCapture. I downloaded the free ZWO interface, ASICap, and readied my laptop to use it the next clear evening.

The ASICap did the trick. As soon as I switched to 11 bit mode the frame rates could be boosted significantly, up to 150 fps on Jupiter with a tightly cropped ROI. With a faster speed there is a greater chance of catching more of those milliseconds long windows of stable seeing, hopefully leading to more sharp images in the sample. Of course seeing has a lot to do with the outcome regardless of fps, and so far I've not had a really good night of steady skies.

One unforeseen (but predictable) consequence of the higher frame rate is the much larger video file that is produced. Previously a 2 minute run on Jupiter yielded about a 2-3 GB AVI file, but now I am producing files that hit 7-9 GB in size. This then leads to a storage issue with no really great solution (at least not suitable economically). I will probably fill up my 2nd TB of online storage by October, so I will have to come up with a plan. Right now I am thinking of starting to rate the video captures in terms of quality and interest with an eye to discarding those below a certain rank (contrary to my planetary video hoarding tendency). 

ASI178 at work

 

One unexpected benefit with using the ASI178 is the much larger field one can start at, making it much easier to find the target, center it, and only then reduce your ROI to have it fill most of the frame.

In terms of the ASICap interface, while it is workable I still prefer FireCapture. For one thing I like having the ability to briefly pause the capture and nudge my target back into the field if it has drifted out. I also find the more prominent display of the metrics during capture (fps, elapsed time, file size) much easier than the small font at the bottom of the ASICap screen. I also like that everything of importance fits on the FireCapture screen whereas I find myself scrolling a good deal in ASICap. 

Hopefully an evening with some steady seeing will present itself soon so that I can get a true sense of what the camera can achieve. In the meantime, as often happens when I have new equipment, I plan on spending some time searching CloudyNights and YouTube for tips and advice from my fellow planetary imagers.

 

Why Bother?

What is it that causes someone to undertake astronomy as a hobby? I certainly believe that one of the primary drivers is the majesty of the night sky - especially when unencumbered by light pollution. It is a visceral awe that arises from your soul when you behold a sky that is ablaze with stars. 

Milky Way over Blackwater Wildlife Refuge - by Cheryl Kerr

Another incentive is the invitation to ponder the fantastic. We learn of things such as suns collapsed down to neutrons where a pea-sized portion of it would be measured in tons, and we contemplate storms on other planets lasting centuries.

Yet a third enticement is the thought that one might contribute to that body of knowledge. In bygone decades the discovery of a comet was the goal of many a dedicated amateur observer. Others have fastidiously and relentless made magnitude estimates of variable stars, or timed the central meridian crossing of Jovian features. But then the automatons arrived, tireless robotic scopes and orbiting observatories capable of being the eyes on the universe in a way amateurs cannot match.

The perceived loss of relevance is certainly real. Witness the genuine excitement of our community at the prospect of providing exo-planet transit timings to help scientist improve their knowledge about these distant worlds. I fully expect companies like Celestron to soon begin marketing tools to help those who wish to participate in this work.

Planetary observing has been an astronomical passion since my first “real” telescope that enabled me to see features. I started by sketching Jupiter, Saturn, Mars, and Venus to submit to the Association of Lunar and Planetary Observers (ALPO). More recently I’ve taken up imaging as it yields results that are far superior to my aging eyes and artistic talent.

After so many years of just being an ALPO member, I decided last year to volunteer as the coordinator who posts images and sketches from observers across the globe to the ALPO gallery. Twice this week, in email exchanges with individuals who contribute their work to the gallery, I encountered the sense of inadequacy. “It is impossible to keep up with the big guns,” was the lament from one. It can be deflating when comparing one's work to the astounding images produced by amateurs equipped with larger scopes, deeper pockets, and a firm dedication to their craft. Indeed, why bother to capture an image when you know there are others whose work is consistently an order of magnitude better than what you can achieve?

First, I’d argue that self-improvement is never a wasted effort! As you become more familiar with the equipment and software your end result will look better and better. This, in turn, is likely to encourage you to buy that next piece of equipment or program that can push your current boundaries of expertise. You may never reproduce the results of someone like Damien Peach, but that is true with any hobby – from needlepoint to swimming there are dedicated “amateurs” who will always be the ones we strive to emulate.

My Mars images from 2018 and 2020

 

Secondly, you’ll never know when it will in fact be you who witnesses a rare event. It happened to Ethan Chappel two years ago as he was carrying out “lucky imaging” of Jupiter when he recorded a momentary bright flash that turned out to be a boulder-sized meteor striking the planet. He was the only person to capture the event which helps scientists to calculate the frequency of such impacts at Jupiter. If it happened to Ethan (and others over the last decade), it could certainly be you the next time.

A final motivation is that your observation is likely unique. The top gun amateurs are not out there 24x7 capturing video of the major planets. Your photo or sketch can be very useful in determining the drift in longitude of a Jovian cloud feature, pinpointing when and where that Martian dust storm originated, or refining a brightness estimate of an inbound comet. Advancing science is often achieved through many data points – be one of them!

 

Yes, the professionals and leading amateurs have the equipment and resources to provide us with stunning planetary images. But that should not be any reason to rule out the citizen scientist role you can play by persistently going out and reporting on what you see to organizations like ALPO. Keep refining your skills and keep looking up – who knows what opportunity for discovery you might encounter?