Yesterday, I repeated my Live High Dynamic Range (LHDR) testing with the DS10c, this time using a Celestron 6” Telescope with the Optec NextGen Maxfield 0.33X reducer, which produced about a f/3.3 setup.
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I didn’t get as much detail at this point as I previously had using my 8” with Hyperstar at f/2.  So I decided to try using bin 2, leaving all the settings the same and repeating the process, but changing the gain from 4 to 40 after 5 output images, and from 40 to 80 after 5 more output images, and let it run for 10 more output images (20 total output).  The final captured image is shown below.

Bin 2, 3 second exposure, histogram 7-255, 15 averaged output frames at gain of 4 plus 15 averaged output frames at gain of 40, plus 30 averaged output frames at gain of 80 using live stacking.​

I was pleased with the results of using bin 2 with 3 second exposure on a 6” telescope at f/3.3 using the LHDR process with 4, 40 and 80 gain settings.

Even though this is somewhat “like” an astrophotography process averaging frames with different settings, it still has the “live” feel that makes Video Astronomy so much fun.  I get to see results in near real time in amazing detail and color that I never could see with these eyes of mine looking through a telescope! And you can experiment with different settings and quickly see the results.
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To compare this result to using the LHDR process on a 8” telescope with Hyperstar operating at f/2 see my prior blog post at

remotevideoastronomy.com/blog/ds10c-live-hdr-averaging


12/12/2018 UPDATE: 

Matt Harmston has done some outstanding work expanding the use of this LHDR technique!  He found you could in fact make use of LHDR techniques while using trigger mode.  This opens up LHDR to anyone since video mode is Not a requirement, and thus it is no longer limited to under 5 second exposures.

He found that while using trigger mode you can stop looping without stopping averaging, change the gain, and then restart looping right where you left off still averaging with the prior image!  The key is to not disable averaging during this process.  I have found it actually makes it somewhat easier since you can stop looping at a certain point and take your time to change the gain (and/or other settings).  Then you just turn looping back on and the average stacking continues.  You can do this as many times as you like to continue developing a LHDR image!    Instead of changing the gain, you can also do this varying other settings like the exposure time, histogram, gamma, contrast, etc.

​Some Deep Sky Objects have a wide range of detail, but present a challenge.  For example, you can see the Trapezium stars in the core of the Orion Nebula if you use a short exposure.  To see the fine edge detail you need to use longer exposures, but that “blows out” the core and you can no longer distinguish the Trapezium.  This can be overcome using a High Dynamic Range technique by capturing several images of varying exposure and post process them later to combine them and produce a final image with a good range of detail.  It would be nice to see this in real time though.

I tried something interesting last night that is somewhat like a Live High Dynamic Range (LHDR) averaging technique.  I was using my Celestron 8” with Hyperstar with the DS10c aimed at the Orion Nebula. The 3/4 moon was rising so I was also using a Baader Planetarium Moon and Skyglow filter.  The key settings I used that remained constant were: 1 second exposure (video mode), histogram 65-255 and sharpen at 100. I did not use binning. I started with gain at 4 and turned on planet averaging with align. After it output 12 frames I moved the gain slider up to 40 and let it continue averaging.  After it averaged 12 more frames I moved the gain slider up to 80 and let it continue.  Looking at the screen after it averaged 12 more frames I decided to let it just continue averaging at gain 80.  After it had averaged 19 more frames I captured the final averaged image.  I took snap images each time I changed the gain so I could show how the image “developed”. No post processing was done on any of these images of M42.

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Gain of 4, 1 second, histogram 65-255, 12 averaged frames using live stacking.

On the right is a cropped version of an image capture using gain of 4, 1 second, histogram 65-255, and frame averaging without using this LHDR technique.  You can see the outer fine detail, but the core is overexposed and you cannot distinguish the Trapezium like you can in the LHDR image on the left.
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The Miloslick software for the Xtreme/Xterminator cameras has a HDR mode for objects like the Orion Nebula that can automatically vary the exposure time over several frames combining them in real time to produce a nice detail in the image viewed on the screen.  I could have varied the exposure time instead of the gain during average stacking in video mode in the MallinCamSky application, but chose to vary the gain because I could get a much wider dynamic range in a short period of time by just varying the gain of the DS10c and leaving the exposure time at 1 second. I had to make the changes by hand during averaging with MallnCamSky, but it worked!
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M33 Triangulum Galaxy, 3 second exposure, histogram 50-150 ​

​Viewing Fun

Some portions of each night were clearer than others and there was occasional ground fog to contend with, but all in all it was great fun seeing these objects with my new equipment in very near real time!  Viewing night sky objects through an eyepiece in “real time” is still a great experience, but you are limited by what the human eye can see at night.  I remember when I first discovered video astronomy it opened up a whole new viewing experience for me, seeing objects through my telescope in color using a camera in a way I couldn’t possible see in an eyepiece.   I feel like this new equipment combination which has a very star-rich wide field of view enabling less than 5 second exposures has taken video astronomy to another level for me. As I have said before, video astronomy is like a viewing session.  It is not about capturing perfect pictures --- it’s about seeing many amazing images of night sky objects appear on your screen in near real time. And you can capture images like these to remind you of what you saw, and later have more fun looking at details you may have missed.

The SkyBT runs on two AAA batteries (alkaline or rechargeable).  You can also power it with a DC power adapter 4-9v @ 1 AMP (only use NiMH rechargeable batteries when externally powering the SkyBT). Push on the end of the SkyBT and swing the cover up to insert the batteries.  Then push the cover back on the SkyBT.).
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​The SkyBT is smaller than the SkyFi device. Like the SkyFi, it connects to the mount hand control using a serial adapter cable. ​

After turning on your mount and performing an alignment, turn on the SkyBT by pressing the red button on the back until the green light begins flashing.
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Turn on your Android tablet / phone and be sure Bluetooth is turned on.  The first time you use SkyBT you will need to pair it to your Android device. Select Bluetooth from your Android settings screen and select the FireFlyBP-xxxx device (the last 4 characters vary by device). Enter 1234 for the pin when prompted to complete the pairing.
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Start SkySafari on your Android device (be sure to get the version that supports telescope control). The first time you will need to set up your equipment by tapping on Setting from the bottom of the SkySafari screen.  Scroll down and select Setup under the Telescope section. Set your Scope Type (e.g. Celestron NexStar GPS/SLT/SE) and Mount Type (e.g Alt-Az GoTo). Under Communication Settings, select Connect via Bluetooth. Now return to the main SkySafari screen and tap Scope at the bottom of the screen. Tap on Connect, and after a few seconds you should see it connect to your scope and display the area of the sky where your telescope is pointed.   The yellow LED will flash showing SkySafari is communicating with your telescope mount.
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Now you can tap Search at the bottom of the SkySafari screen and select a target object.  Tapping GoTo will slew the telescope to the selected target.  You can use the left/right and up/down buttons on the side of the screen to make small position adjustments. 
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hen you are finished, press and hold the red buttion on the back of the SkyBT for 3 seconds to turn it off.  The next time you turn on your SkyBT and Android tablet, all you need to do is run SkySafari and tap on Connect at the bottom of the SkySafari screen to automatically connect to your mount via Bluetooth.
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After verifying my new SkyBT worked well with the Android tablet, I got side tracked having fun viewing with this setup.  It provides a nice wide field of view and pretty good sensitivity. Here are some image captures (no post processing) with exposure set at 10 seconds. This is from my driveway at my house near a city where sky glow is an issue.
 
M11 Wild-Duck Cluster​

 I was pleased with what I saw with my smaller 5" SCT scope and the DS3.2+ while using SkyBT and SkySafari to select and slew my telescope to various targets.

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10/30/2017 Update

Simulation Curriculum also has a SkyFi 3 device that works over Wi-Fi with both iOS and Android devices.  It cost more than the BT version, but SkyFi 3 can Wi-Fi enable Go-To telescopes with either a standard USB or serial interface, and it has a built in rechargeable battery.

I have received feedback that if you use the SkyBT when it is cold outside, you should consider using disposable Lithium batteries.  The Energizer Ultimate Lithium specs claim they work from -40° F to 140°F, and have a 15 year shelf-life.  You can buy these most anywhere now, and you can buy them in bulk through Amazon. When it gets cold, neither alkaline nor NiMH batteries last as long. Lithium batteries keep on working for hours, even in sub-freezing temperatures.  You could also use external power, either a larger battery or AC powered adapter, provided you have rechargeable batteries inside the SkyBT. 


And I have heard that using SkySafari running on a tablet is great for public outreach, especially with kids.  They love seeing the ability to control the telescope mount with a tablet, particularly if you let them tap the GoTo button sometimes!
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I have eclipse good news and bad news from our site at Columbia, MO.  The bad news is it was cloudy Monday morning during the initial partial eclipse portion.  The good news is it cleared up for the afternoon eclipse portion. 
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The total eclipse was definitely visible, though we still had some light clouds.  Even so, I was amazed when I took off my solar glasses during the total eclipse portion and looked up.  I didn't really know what I expected I could see, but it was better than anything I imagined! The Sun appeared as a dark disk, and I could clearly see the corona extending out from its surface - much further out that I thought it would be.  And it was easily visible to the naked eye! 
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I used my Remote Video Astronomy setup with the laptop inside our camper connected to the DS2.3+ on my PST outside. This allowed the laptop to stay cool (and humans too) while capturing images of the eclipse.

Because of the morning clouds, we couldn't see very well visually through the solar glasses prior to totality, but could at least see the telescope camera image of the progression of the eclipse on the outside display. 
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It cleared up nicely in the afternoon allowing me to capture some good partial eclipse images. We used the solar glasses outside for direct viewing of the Sun during the partial eclipse time.  I would periodically go inside and capture a short exposure showing the Sun’s surface and a longer exposure showing prominences extending from the surface.  These details were also clearly visible on the outside monitor. Below are a couple composite images where I combined a long and short exposure to see both the Sun’s surface and prominences in one image.  
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You can see the rotation of the camera image over time due to my use of an Alt-Az mount.
Here are a series of image captures (no post processing) showing the progression of the partial eclipse after totality (when we had clear skies).
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I recorded a time lapse video during totality using my best guess pre-set exposure. It turned out it was fine for seeing prominences near the surface just after totality, but the exposure setting was not enough to capture corona effects during totality … and I was busy looking up directly with my eyes during totality rather than adjusting the camera settings.  Looking directly at the Sun and seeing the corona around it was very captivating! ​

Here is a link to my time lapse recording that does give a feel of the total eclipse event. It also conveys the dramatic difference between the partial eclipse portion and the total eclipse portion.  Not to sound trite, but it is literally a night and day difference.

www.youtube.com/watch?v=Zzm6GRg-S84

It was during the dark portion of this time lapse video clip that we were able to look up directly at the Sun and see the corona extending out from it. Since I did not capture any images during totality, Thom Pfeil has allowed me to post the following image he captured, which is an excellent reminder of what we saw as we looked up that day...
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​In spite of the initial morning cloudy skies, the trip was well worth it. I'll never forget what I saw as I looked up during totality, and I enjoyed experiencing the images from the DS2.3+ both in real time and later as captured images.​
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So, in seven years I’ll be ready to apply what I learned and do this all over again.  Who knows what advances we will see in video astronomy in seven years!

One person has an ingenious pin hole eclipse viewing box on a tripod setup making it easy to track and see the Eclipse – no solar glasses needed.
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​My Remote Video Astronomy setup is just outside our camper. While previously testing one day outside back home in MS for over 3 hot hours, I had problems with my laptop overheating.  So I now place my laptop inside our Camper with USB3 extension cables out to the DS2.3+ and a long HDMI cable from inside to a monitor outside. I used SkyFi + SkySafari on my iPhone to center the image as needed from inside or outside.  A companion program to SkySafari was released for this eclipse called Eclipse Safari that provided local information about the Eclipse.​

My Remote Video Astronomy setup will allow us be to outside to periodically look at the Sun through solar glasses, as well as see the camera image on the outside monitor as the eclipse progresses.  I used my MallinCam DS2.3+ with a Coronado PST on a SkyProdigy mount. I unscrewed the lens from my Coronado Barlow and screwed it into the nosepiece of the DS2.3+ which produces an easily focused image that fills the field of view (as I described in my 8/3/2017 post). ​

I hope to turn on auto recording just before totality begins and then go outside to experience the total eclipse of the Sun. 
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I captured several images during the test time and settled on periodically grabbing two images at a time - one showing prominences and the other the Sun's surface.  I can then combine them later to produce a composite image.
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Of course all this is very dependent on the weather here.  As I write this on Sunday, the day before the Eclipse, it rained this morning, but the Sun just came out and it looks nice again outside this afternoon. The prediction for tomorrow (which changes constantly) is for partly cloudy skies. If there is light rain, I even have an umbrella ready.
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I'll be happy for just occasional views of the Eclipse! 

But as they say, the best laid plans of Mice and Men...
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I have found two very good reasons for using Remote Video Astronomy (RVA) for capturing images of the Sun in the summer:

1.       It is hot outside and that makes humans uncomfortable
2.       It is hot outside and that makes laptops really uncomfortable

As I was testing my setup for the upcoming eclipse, I found my laptop would start to overheat if it was outside next to my telescope. The fact that the laptop is black didn’t help any.  I tried putting it under a covering and aiming a fan at it, but it still would overheat and declare it was shutting off.  This is the last thing I needed to occur at high noon (i.e. 1pm Daylight Savings time) on the day of the eclipse when totality would start 12 minutes later.

So I have opted for the RVA solution I have used many times before – using active USB extension cables to run inside to my laptop so it can stay cool and record the eclipse.  I use SkyFi at the telescope and SkySafari on my iPhone to control the mount from inside.  
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I can go inside to cool down my body, and then go outside again to visually look and see how the eclipse is going (wearing certified eclipse glasses of course – never ever look at the Sun directly without proper certified protection -  do not use sunglasses).

I am going to be using a MallinCam DS2.3+ for the eclipse, which uses USB3.  My laptop has a USB3 port that I can plug the MallinCam USB3 cable into.   The following 10M active USB3 extension cable has worked well for me when I need more cable length. It is currently available on Amazon for about $35 and a compatible power adapter for about $7.50.
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Due to the higher speed and specs of USB3, these cables have a power connector on the female end of the cable.  I plug its power adapter in at the telescope and insert the DS2.3+ USB3 cable into the end of the active USB3 extension cable.  I plug the other end of the USB3 extension cable directly into my laptop inside.
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If more distance is needed, I use a second USB3 extension cable to the laptop. If you use two cables, you may only need to plug power into the cable at the telescope end.  Since the DS2.3+ draws its power from the USB3 cable, powering that end of the cable gives plenty of voltage to run the DS2.3+.  If you do have communications issues when using two cables, you probably need to supply power to the end of the other cable as well where the two USB3 extension cables are connected.
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Earlier this year I purchased a Coronado Personal Solar Telescope (PST) and was very impressed with what I could see with this entry level Solar Telescope, both visually and with a video astronomy camera (see my 1/16/2016, 1/17/2016 and 2/14/2016 blogs).  In my 3/17/2016 blog I discuss the importance of using the Histogram function when viewing deep sky objects with the MallinCam SkyRaider cameras. 
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Today I decided to get my PST back out and try out using the Histogram function while viewing the Sun using my MallinCam AGc (color) video astronomy camera.  Since we were camping, it also gave me a good chance to try out solar observing from inside the camper using Remote Video Astronomy.  I did have to put forth the effort outside in the summer heat to get set up, but then it was really nice observing and trying out different Histogram settings while inside where it is cool and comfortable and easy to see the screen.

You can click on the following link to see a video clip showing the benefit of using the Histogram Function when viewing the Sun using video astronomy.

https://youtu.be/I9OfFGIe_EM


Description of the setup process

I set up my SkyProdigy mount with the PST on it next to the camper, performed a solar system align with the Sun using a Coronado eyepiece to visually center the Sun for the alignment and adjust the telescope focus.  After I switched to Solar tracking, I added a Coronado Barlow to see more detail.  Now I was ready to change over to video observing.

I removed the Coronado eyepiece and inserted the AGc camera, attached its USB cable and connected it to my laptop on a table next to the telescope. After turning on the laptop and starting MALLINCAMSKY, I selected the AGc camera and set the exposure to 20 ms with a gain of 1.  The next step was the hardest one – focusing with the camera in place while outside in the bright sun! I have found placing a dark shirt over your head and laptop screen while adjusting the focus works really well.

Once focused, I disconnected the laptop and moved it inside.  I ran an active USB extension cable from the camera to inside the camper through a port I added to the camper (see my 8/5/2015 blog). I placed my SkyFi module on the tripod tray, connected it to the serial port of the hand controller and turned the SkyFi module on (see Remote Telescope Control section in my 4/24/16 blog).  Here is my outside setup.

Results

I was then ready to view the Sun from inside and remotely control the telescope using SkySafari on my iPhone. I began with the exposure set to 20 ms and the Histogram (blue arrow below) at its full default values (0 & 250).

​I then moved the upper limit (green arrow below) close to the right end of the red curve (red arrow) and the lower limit (blue arrow) somewhat near the left end of the red curve.  This really brought out the surface detail of the Sun!

​Next I tried the same technique to bring out the detail of prominences better. Earlier this year I found out that increasing the exposure diminishes the surface detail but enhances solar prominences so they can be seen.  I clicked on the Default button (blue arrow below) in the Histogram and ran the exposure from 20ms up to 90ms so I could faintly see some prominences (yellow arrows).

​I noticed the red curve was now near the left side of the histogram (red arrow below).  I moved the upper limit (green arrow) near the right edge of the red curve. This really brought out the detail of the prominences!

​I then clicked on the Default button (blue arrow below) in the Histogram like before and used SkySafari on my iPhone to position the telescope view to the lower right portion of the Sun and could see some prominences (yellow arrows).

​Again I noticed the red curve was near the left edge of the histogram (red arrow below) and moved the upper limit (green arrow) near the right edge of the red curve. This brought out the detail of a spectacular prominence (yellow arrow)!

Conclusion

​Based on these results, I definitely concluded that the real time Histogram function is very beneficial to observing the Sun with Video Astronomy!