Greg Marshall


About Greg Marshall

I am a retired electronics engineer and after a few months of enjoying my leisure I began to miss doing product development. My astronomy hobby always needed new solutions to unique problems, so I decided that whenever I came up with a good solution I would try to make it available to others.


What’s Wrong with a Super Blue Blood Moon?

It was cloudy here on the morning of Jan. 31st, so we didn’t get to see the lunar eclipse – or photograph it.  Fortunately, my friend Mike McKeag was in southern California and managed to get this great shot of the Moon with background stars. I did get a lot of questions about this much-hyped event, so thought I’d summarize the answers here: A “Super Moon” just means that the Moon is near the time in its orbit where it is closest to Earth (at perigee), so it appears bigger and brighter. Since no one pays much attention to it […]


Standing Room Only

Last week I visited Sierra Remote Observatory (SRO), a telescope hosting service.  What that means is that people install their telescope at SRO and operate them over the internet to capture images.  There are both private (amateur) and professional astronomy operations located here, and it’s very popular, which explains why the other common meaning for “SRO”, standing room only, might apply.  There are 2 large buildings like this that are filled with telescopes, most of them quite large.  There are also smaller buildings, visible on the left in this photo, that house individual telescopes.  There are no available spaces at […]


Looking Back (and Forward)

One of the greatest things about astronomy is that when we look at very distant objects in the universe we are actually looking back in time.  Because it takes time for light (and other “signals”) to reach us over huge distances, we can literally see what things were like long ago.  Thus, the science of astronomy is largely about history.  The difference between astronomers and historians is that astronomers have to use a lot of tricky extrapolation and inference to learn about the past. I, on the other hand, can tell you about the recent past of Wa-chur-ed Observatory directly […]


Air & Space Photo Contest 1

Air & Space Magazine, published by the Smithsonian Institution, has an annual photo contest with 4 categories, including one for astronomy photos.  I submitted 10 images last Fall, including 1 collaborative image done with my friend, Kay Wyatt.  The judges have selected 10 finalists in each category, and I’m pleased to announce that our collaboration and 3 of my own images are among the Astronomy finalists! The judges will eventually choose a winner in each category, plus a Grand Prize winner across all categories.  But there is also a Readers’ Choice award.  You can vote for your favorite image in […]


New Focus Control System (Finally) Available

I told you about PerfectStar B some time ago – it’s my new focus control system using bipolar motors instead of the traditional unipolar motors.  And I had intended to put it on my website and start accepting orders back in September, but ran into some software issues that delayed the release just enough to push it into the busiest time of year, so I didn’t get around to updating the website until now, even though I have already shipped a couple of these to existing customers. The “B” in the name refers to its use of/support for bipolar stepper […]


PerfectStar B Focus Motor

Along with the new PerfectStar B (PSB) Focus Controller, the PSB Focus Motor provides faster movement and additional features in comparison to the classic PerfectStar motor or other unipolar stepper motor.  The PSB Focus Motor attaches to many models of telescope in the same manner as the classic PerfectStar motor, using a 2-part coupler contained within a housing that attaches with thumb screws to your dual-speed focuser.  Other types of coupling, including SCT models, are available as custom orders. The PSB motor differs from the classic model in that the housing is metal, which makes it more rugged, reduces the […]


PerfectStar B Focus Controller

Building on the success of the classic PerfectStar Focus Controller, PerfectStar B (PSB) is the next generation controller, with enhanced speed, torque, and programmability. It is also a step up in production quality, featuring metal construction, engraved labeling, and better cables and connectors. But the essence of PSB is its support for biploar stepper motors. The classic PerfectStar, like most focus systems until now, uses unipolar stepper motors. Unipolar motors were probably originally chosen because they require less sophisticated electronics to drive them. But bipolar motors offer many technical advantages, and since they are now widely used in many areas, […]


2018 Calendar Now Available

The 2018 Calendar of Astro-Photography is now available!  For this edition the title is modified from the usual “Night Visions” to “Sky Visions: Night & Day” because a good portion of the photos included are of the Sun, including several from the Aug. 21, 2017 Total Solar Eclipse. As you can see from the cover, three other photographers have contributed to the calendar this year.  Bob Yoesle is a very skilled solar observer and photographer, and has provided images of the Sun captured with different filters.  Kay Wyatt and Michael McKeag are friends who both got better pictures of the […]


Early Christmas

For many years the AT111EDT has been my “workhorse” telescope, and it has been great, for the most part.  No longer in production, it is a widely regarded triplet refractor with an excellent optical design for its price point.  However, for the last few years I have been wanting to upgrade.  Specifically, I wanted the ‘scope pictured above (stock photo), the William Optics FLT-132.  Aside from having a significantly larger aperture, the FLT-132 uses a better grade of glass for the ED element, resulting in less chromatic aberration.  This has been a problem for me when capturing LRGB images with […]


LIGO Announces First GW Detection of Colliding Neutron Stars

You probably heard about this announcement from LIGO yesterday, but I thought I should add some details, and shift the emphasis of the story to where it really belongs: The previous detections of gravitational waves (GW) all originated from the merging of large black holes.  Such mergers can produce relatively strong, but very brief GWs – just a small fraction of a second.  And they produce nothing else – no light or other electromagnetic radiation.  Therefore, these observations could not be confirmed by optical telescopes or other detectors. In contrast, this event, dubbed “GW170817” because it was detected on Aug. […]