The COVID-19 pandemic in the U.S. has posed serious challenges to local astronomy clubs in terms of conducting their public stargazing events. Initially, many clubs (including the South Plains Astronomy Club) simply cancelled their public events in response to the stay-at-home recommendations by state and local governments. However, as regulations concerning social gatherings are being relaxed in many places, astronomy clubs are beginning to consider resuming public stargazing activities.

Public stargazing events have some unique challenges related to preventing the spread of the COVID-19 virus from person to person. Besides gathering around telescopes, people have a tendency to touch and breathe upon the scopes in the process of steadying, focusing, and viewing through them (as shown in the photo above). This could potentially provide a mechanism for transferring the virus from one person to the next. Requiring visitors to wear N95 masks and surgical gloves could mitigate the problem, but getting everyone to comply might be challenging and could be expensive if the club chose to provide these items. And trying to disinfect a telescope between successive observers using sprays or wipes is not practical.

Are there ways that visitors to public stargazing events could observe the objects viewed by telescopes without having to touch or get near the telescopes? The answer is yes— through the application of modern digital photographic and imaging technology. In the June 2020 edition of Sky & Telescope, author Rod Mollise describes the use of small, inexpensive video cameras attached to telescopes to send the view of the observed object to a nearby video monitor or laptop computer. Visitors can comfortably view the object on those devices without having to crowd around the telescope.

While Mollise's article was not aimed specifically at the COVID-19 situation, the techniques he describes can address solving the potential contamination problem. While seeing an object on a video screen is not the same as actually looking through the telescope, it goes a long way to satisfying public distancing recommendations and thus allows clubs to safely hold public stargazing events. Of course, once the pandemic is gone, clubs can return to their normal operations, but this might not be for many months.

At its June 2020 monthly meeting, the South Plains Astronomy Club decided to explore the use of non-contact observing methods for its future public stargazing events. Since a number of possible technologies exist, club members were encouraged to investigate and try out various approaches and report their findings to the rest of the club. This webpage will allow club members to post these results so that others (including the general public) can learn from their efforts and work toward common solutions.



A photocopy of Rod Mollise's article from the June 2020 edition of Sky & Telescope can be viewed here.



Test of Three Cameras: Moon (Steve Maas, 03 July 2020)

I finally got a reasonably clear night so I was able to test the three cameras that I have previously described: the SVBONY USB Camera, the Meade Electronic Eyepiece, and the Revolution Imager. The moon was up and nearly full, so it was the logical target— it pretty much washed out everything else in the sky. Luckily I could still see some of the brightest stars, which was needed to align the telescope mount.

I set up the equipment on the deck behind my house— I have a pier there which allows for a more stable setup (see the left image below). I used SharpCap to display and capture images from all three camera. The laptop was a Dell Inspiron with a 15" (diagonal) display. As shown in the image on the right, the camera display on the laptop is large enough so that people standing around it could easily view it. Regarding the observing conditions— the moon was so bright that I had to use my 1.25" Orion Variable Polarizer (photo below) on all three cameras. Without it, all of the cameras were washed-out regardless of the camera settings. Also, the seeing was not good so there was considerable vacillation in the sharpness of the video from the camera. I ended up capturing a bunch of still images for each camera and then choosing the sharpest to display here.


I tested the SVBONY USB camera first. With SharpCap, you can directly control the camera. Initially, I set the camera gain to about 1/3 its range— with bright targets like the moon or Jupiter you can use a relatively low gain. The higher the gain, the more sensitive the camera sensor (but also more grainy the image). The SVBONY has exposure times ranging from 1/60 second up to 1/2 second. By trial and error, I found that an exposure of 1/30 second resulted in a good image. The image was further improved by adjusting the brightness and contrast.

A couple of images captured from the SVBONY are presented below. The SVBONY is a color camera— using the "automatic white point adjustment" resulted in a reddish hue in the pictures below. It's possible to manually adjust the color balance of the camera, but I didn't mess with it last night. The image frame (1920 X 1080 pixels) almost captures all of the moon, as shown in the left image. A focal reducer would fit the moon in the frame but, unfortunately, my Orion StarBlast scope won't come to focus with my 0.5X focal reducer attached to the camera. The detail in the image is pretty good considering the poor seeing, as shown in the right image (note the sharpness of the crater Plato and the crater along the limb).


A couple of images captured from the Meade Electronic Eyepiece are presented below. This device produced a more "close-up" view of the moon compared to the SVBONY. This is a monochrome camera, so there's no color. You cannot control the camera settings with SharpCap— you have to manually adjust the camera gain using the small wheel on the side of the camera body. You can adjust the final brightness and contrast of the displayed image using SharpCap once you've manually set the gain. By adjusting the gain, brightness and contrast, you can manipulate the appearance of the image, as shown in the two examples below. The sharpness of the images is pretty good, but it was probably affected by the poor seeing conditions.


Finally, a couple of images captured from the Revolution Imager are presented below. This is a color camera but, with the automatic color balance "on", the resulting images were pretty much monochrome. You can manually adjust the color balance. You cannot directly control the Revolution Imager using SharpCap— it is controlled using a small keypad, with the settings being overlayed on the displayed image (see the image on the right). Once you've got the camera controls to your liking, you can turn them off so you can just see the image. You can then adjust the final brightness and contrast of the displayed image using SharpCap. The camera has a wide range of exposure times, from 1/10,000 second to 5 seconds. For the moon, I found that an exposure of 1/4000 second worked best. The Revolution Imager has the ability to automatically stack images. I tried this feature, but it didn't seem to noticeably affect the images of the moon (probably because the moon is already so bright).


So, which camera was the best for imaging the moon? Actually, they all did a decent job under the less-than-perfect seeing conditions. Also, keep in mind that the Orion StarBlast is a "novice" scope— using a high-quality scope would probably produce better results. In particular, with the simple focuser on the StarBlast, it's difficult to achieve a really sharp focus. Something like a dual-speed Crayford would work much better. And, as Mollise points out in his article, you need to have a scope/mount that will track the object.

In summary, any of these cameras would probably be acceptable for non-contact observing the moon at public stargazing events. They're all capable of displaying the major craters, ray systems and maria, which are what visitors to these events are usually interested in. Since the Revolution Imager is capable of imaging dimmer objects like galaxies and nebulas (due to its longer exposure times and stacking capability), I'd probably reserve it for viewing those and assign the simpler systems (like the SVBONY and the Meade Electronic Eyepiece) to the moon.



Modified USB Webcam (Randy DeLung, 30 June 2020)

Made from a old plastic Barlow lens. Cut down for a wider angle. Fastened to a old hang-around web cam. Works well with my laptop. This is about as cheap as one can get!





SVBONY Color USB Astronomy Camera (Steve Maas, 25 June 2020)

While I was waiting for the small USB camera that I previously ordered to arrive here from China, I purchased another small USB camera that is advertised as an astronomy camera. This is the SVBONY Model SV105 Astronomical Camera (see the photos below). It is available from a number of sellers on eBay, but I bought it from the svbonyflagstore for $42.99 (free shipping). It shipped from Chino, CA, so it only took a few days to get here.


This is a small, well-constructed device. The body is made from an aluminum alloy, not plastic, so it feels substantial. It uses a 1/3" 2 Mpix color CMOS sensor (1920 X 1080 pixels, 3μm square pixels)— this is similar in size to what you might find in many autoguiding cameras. SVBONY also offers an 8 Mpix version (Model SV205) with 3264 X 2448 pixels (1.4μm square pixels) for $89.99. SVBONY recommends their cameras for lunar and planetary observation, but it will be interesting to see how the SV105 performs for other objects like double stars and star clusters.

The camera attaches to the laptop with a USB cable— they recommend using the one that comes with the camera. It's 5 feet long, so it should be good for use in the field. SVBONY recommends using SharpCap (see my previous post) for viewing the imagery and controlling the camera. After attaching the camera and launching SharpCap, the camera showed up ("SVBONY SV105") in the "Cameras" dropdown menu. Since the CMOS chip is fairly large, the image filled the display panel of the application and I had to use the "Zoom" function to shrink it down to display all of it.

The camera worked perfectly out-of-the-box. So, as soon as I get a clear night, I'll test this camera along with the Revolution Imager and the Meade Electronic Eyepiece on some astronomical objects. It will also be interesting to see how the SV105 performs compared to the much-cheaper USB camera that I ordered from China.



Using a Laptop to Display and Capture Images (Steve Maas, 23 June 2020)

For imaging systems like the Revolution Imager or the Meade Electronic Eyepiece that produce a composite video output, a portable video monitor is a simple solution for viewing their imagery. However, another option is using a laptop. One reason is availability— while not everyone may own a portable video monitor, practically everyone has a laptop. But there are other advantages to using a laptop, including the ability to capture imagery from the camera so you can view it (or post it on a website) later. Also, laptops have their own battery, so you don't need a separate power source like with a video monitor. In the rest of this posting I'll be talking about Windows laptops (with which I'm familiar), but the information probably also applies to other systems.

The two main types of connections that you'd be dealing with for the types of cameras we're discussing are composite video ("yellow plug") and USB (see the image below). Of course, all modern laptops have USB connectors, so connecting a USB camera is straight-forward. However, most laptops don't have composite video connectors. You're going to need an adapter to go between the composite video cable and the laptop. Luckily, such adapters are available and generally quite inexpensive. I got one free when I bought my Revolution Imager (see the photo below), but they are readily available from sellers such as Amazon, many for less than $20. These "Video Capture Adapters" provide a USB connection to the laptop. Once you connect your camera to the laptop using the adapter and turn the camera on, it should show up in the Windows Device Manager. A special "driver" for the camera is generally not required.


Once you've successfully made the connection between the camera and the laptop, there's several ways to view the camera output. In Windows 10, you can use the "Camera" application that comes with the operating system. You can find it in the alphabetical list of applications (programs) in the Windows Start Menu. If your laptop has a built-in camera, the live image feed from that device will probably be displayed as the default. If so, you can switch to your astro-imaging camera by clicking the small "Change Camera" icon on the side of the application window.

The photo below is a shot of the Camera application in action. Here, I've got the Meade Electronic Eyepiece attached to the laptop using the adapter (I'm test bedding it in my house with the telescope pointed out a window at a distant telephone pole). As you can see, the displayed image is quite large which is good if you're trying to show it to a group of people standing around the laptop. This is a live video display from the camera, but if you want to capture the image (actually, a frame of the video), click the "Take Photo" button. When you do this, a small thumbnail of the captured image will be displayed below the button and the image will be automatically saved as a JPEG to the "Camera Roll" folder in the Windows "Pictures" folder.


If you bought a Video Capture Adapter, it probably came with a small CD that contains an application for viewing the camera output (see the photo below). This application is usually some version of the program "EasyCAP", but it may vary in name and appearance depending on the adapter manufacturer. Once you've installed it, you can usually launch it from an icon on your Desktop. It may ask you to type in the product key, which can usually be found printed on the CD.

The photo below is a shot of the application in action. The panel in the application showing the live feed from the camera isn't really large, and I haven't found a way to maximize the window (I can only minimize and restore it). If you want to capture a frame of the video, click the small "Snapshot" icon— the image will be automatically saved as a JPEG to a folder called "VHS to DVD" under your Windows "Users" folder (the path is C:\Users\xxxx\Documents\VHS to DVD\, where "xxxx" is your computer name). A small thumbnail of the image will appear in the area along the right border of the window. If you want to capture the live video feed, click the red "record" button and it will be saved in the same folder as an MPEG movie. These features might vary depending on the manufacturer of the video adapter.


A third option is to use a third-party application to view the camera output. A search on the Internet will reveal a number of these, many of which are "free". I'm always cautious about "free" software downloads because you never know what you might be getting. One that I am familiar with and can vouch for its safety is SharpCap, which you can download for free. They also have a "Pro" version that you have to pay for, but it's not needed for what we want to do. SharpCap is a full-fledged image processing application that allows you to do things like apply dark frames and stack images, but the part we want is its video display capability. Once it's installed, you can launch SharpCap from an icon on your Desktop.

The photos below show the application in action. When the SharpCap window opens, you'll first want to select your camera from the "Cameras" dropdown menu (in this case, it's the "AV TO USB2.0" which indicates the video feed is coming from the video adapter). Initially, the video display may be relatively small, as in the photo below. You can use the "Zoom" function to fill the panel with the video.


Once you've filled the panel with the video, the display is reasonably large (see the photo below). To capture a frame of the live video, click the "Snapshot" icon in the taskbar— the frame will be saved as a PNG file in the folder "SharpCap Captures" which SharpCap created on your Desktop.


All of these applications work well. The Windows 10 Camera application is the simplest to use and provides the largest video display, so it's probably the best choice of the three for displaying the live video from the camera to people gathered around the laptop. SharpCap has some interesting features such as "Live Stacking" which allows it stack images from certain cameras on-the-fly and display the result, similar to what the Revolution Imager can do. In any event, if you own a laptop, you've already got a great device to display imagery from many types of cameras.



Small USB Color Digital Camera (Steve Maas, 20 June 2020)

If you go on eBay, you can find a number of Chinese providers that sell small USB digital cameras affixed with 1.25"-diameter nose pieces that allow them to be used with a telescope (see the photo below). The device is described by the seller as "an affordable introduction to the rewarding hobby of astrophotography. Great for lunar and planetary shots— not suitable for deep space imaging". At least they're honest. These cameras are incredibly inexpensive— I bought one last night from a supplier called "tophosts" for $6.90 plus $4.04 shipping and tax. These cameras contain a color CMOS chip (4.86mm x 3.64mm, 640 x 480 pixels) and are equipped with a standard USB cable that allows them to be attached to a laptop. Like a webcam, they don't require any special software and provide a real-time video display. Power for the camera is provided through the USB connection.

At the SPAC Monthly Meeting last Thursday evening I showed a small Logitech webcam that I speculated might be adapted for use on a telescope, but the Chinese are obviously way ahead of me!


I should get the camera in a couple of weeks and I'm really anxious to try it out. Maybe it won't be the greatest but, at around $10, there's not much to lose.

System requirements for the device are as follows:
IBM PC or compatible PC or laptop with USB port
Pentium 200 or higher CPU
32MB or higher memory
Windows 98SE/ME/2000/Windows XP/Vista/7/8/8.1/10 Operating Systems

Camera Specifications:
CMOS Chip Type: Color CMOS image sensor
Video format: 24 bit RGB
Lens: 1.25"/31.7mm
Video: 640x480 pixels up to 15 frame/sec (VGA)
Frame rate: 320x240 up to 30 frame/sec (CIF)
Sensor size: 4.86mm x 3.64mm
S/N ratio: less than 45dB
Dynamic range: less than 72dB
Focus range: 5cm - infinity
Automatic white background balance
Automatic color compensation




Using a Meade Electronic Eyepiece (Tom Heisey and Steve Maas, 20 June 2020)

Before leaving on his trip, Tom lent me a Meade "Electronic Eyepiece". This is a small monochrome CMOS imaging camera built into the format of a regular telescope eyepiece (see the photo below). The CMOS chip is pretty small (320 X 240 pixels). It produces live composite video output ("yellow plug") that can be sent to a video monitor like the one that comes with the Revolution Imager (see the setup below) or a TV that has composite video input. The device has a small thumb wheel on its side that allows you to adjust the camera gain and thus the contrast of the image. The Electronic Eyepiece runs off of a single 9-volt battery that you install in the device, which is pretty convenient.


I'm guessing this is pretty old imaging technology. Meade has discontinued this item, although you can still find used ones for sale on the Internet for around $70. Meade states that it is good for viewing "the Moon, planets, stars, and land objects" but I would guess that it works best on brighter objects. Unlike the Revolution Imager, it does not automatically stack multiple images, so what you see on the monitor is going to pretty much be what you would normally see through the telescope.

It's been cloudy/rainy lately so I decided to do an initial test of the device in the daytime. I set up the system in my house and pointed the telescope out a window at a distant telephone pole on the horizon (see the photos below). As you can see, the device worked fine with the video monitor— by adjusting the gain on the Electronic Eyepiece you could get good contrast in the image. There was enough detail in the live image to pick out the wires running to the pole (and an occasional bird flying by). As soon as I get a decent night, I'll try it out on the moon and other astronomical objects and report the results here.





Use of the Revolution Imager (Steve Maas, 19 June 2020)

I got a Revolution Imager like that described in Rod Mollise's article last year with the intention of using it at SPAC stargazing events. I purchased it from High Point Scientific for $299.99 and they included a free RI-USB Video Capture Adapter that allows you to hook the camera directly up to a laptop instead of the small video monitor that the camera comes with.

Initially I set the device up on my 5" Meade Maksutov (see the images below). I tried it out with the laptop at the Ransom Canyon Star Party on 24 August 2019. The imager performed well but my main problem was with my telescope— while it has a "GO TO" mount, getting it properly polar-aligned and calibrated is a chore, so I don't usually do it. Thus, I wasn't able to track objects with the scope that night. So, I was constantly adjusting the scope to keep an object in the FOV. I was able to capture some decent images of Jupiter on the laptop (one is shown below).


As Mollise states in his article, you really need to be able to track objects with your scope to get the most out of the Revolution Imager. The camera has the ability to capture up to six images in succession and automatically stack them before sending the resulting image to the monitor. In this way, the resulting images of objects like nebulas often show more detail and color than what you might see just looking through the scope. Of course, to take advantage of this feature, your scope has to accurately track the object.

To get around my laziness in setting up the telescope, I recently invested in new equipment. My new setup is shown below. The mount is an iOptron Cube-G that I bought used. It has a built-in GPS and "SmartStar" software that handles all the alignment automatically. It also has a big "GO TO" list of objects that it will slew to and track automatically. It's really nice! Its only drawback is that it can't support a big scope— it's limited to around 7 pounds of payload. The scope I chose for it is the Orion StarBlast II 4.5" Reflector. It's a little smaller than my Maksutov but is well-suited for use with the iOptron mount due to its light weight. It's a good combination for public stargazing events. All components of this system are battery-powered (mount, camera, video monitor). You could also use a laptop in place of the monitor like I did previously.


I'm hoping to do some testing of the new system as soon as we get some clear skies. I'll report my findings here as soon as I get them.



Using an iPhone and MacBook (Patrice & Rick Fay, 7 June 2020)

Shown below are two screen shots of Mizar-Alcor taken with an iPhone 8Plus attached to an Orion 8" Dob and filmed through a 25mm eyepiece. You might remember that Orion clamp gadget that I had during my Marysville Eclipse talk? It's the same one I'm using to attach the phone to the scope at the eyepiece, clamp also pictured below. We took these images last evening, June 6, around 10:20pm. There was some haze that had moved through the area, the wind was pretty high and had pushed some dust in the sky as well. The iPhone was connected to the 13" MacBook Air using a 10-foot Lightning to Thunderbolt connector cord. Both iPhone and MacBook were running on battery power the whole time, and didn't show signs of running out of power for the time we were out there.


As you can see from the screen shots, I was using QuickTime Player to access the iPhone as the "video" camera to share the phone's screen onto the MacBook. You can see the zoom factor of the iPhone in the left image was 2x and the zoom factor on the right image was 1.4x. In either image below, it is easy to make out the double on the right side of the field of view (Mizar), with Alcor on the left side. A nearby field star is also visible below and between the two main stars. When viewing on the computer screen in person, you can almost see the star color, although that seems to get lost in the screen shots above.

For my set up using the iPhone as the "camera," I'd need to be looking at brighter objects like a planet or double stars or star clusters like the Pleiades or the Beehive. For fainter objects, like say the Hercules Cluster, I'd need a photo multiplier to get good images through the iPhone, and then I'm not sure how to connect everything anyway.

Ultimately, I'd say we have good proof of concept for this set up. It is doable and will work for for a "socially distant" star party with a group of 3-4 people able to comfortably see the screen at any one time.

Rick and I have several outdoor rated power cords and power strips of varying lengths. We would just need to determine where the power plugs are in relation to where our set up would be.

My equipment for this set up:

MacBook Air (13" screen)
iPhone 8Plus
8" dob
Eyepieces
Folding table, (6-foot)
2 camp chairs
Power cord
Short step ladder



 

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