Initial Solar Work With Orion SSSS Color Camera IV

[Skylook123]

The bulk of this post is equivalent to its partner in the Lunar Imaging forum.

Generally speaking, my observing arena is visual. Eyeball at the eyepiece. But, last year, my wife and I participated in observing the sun setting behind the telescopes at Kitt Peak, from 60 miles away on the road up Mount Lemmon. I started thinking about getting images of the sun and moon against various landscapes, and also the potential for using the camera image live during public outreaches. So, in late fall I bought an Orion Starshoot Solor System Color Camera to begin dabbling. I worked with it for 30 or 40 hours over the last two months, trying to learn the settings in software in order to get an image worth looking at.

Here are LOTS of facts, in no particular order, followed by some JPG stills and links to a couple of You Tube uploads I've done.

1. Telescope for the solar effort is the Lunt LS60THa/B600 solar telescope. While sunspots are visible in plain old white light filtered viewing, to see all the rest of the behavior like prominences, flares, mass ejections, faculae, filaments, and other details takes either H-Alpha or, for more odd behavior, Calcium-Potassium designed telescopes. The B600 indicates the level of blocking; this is the basic UV blocking level. B1200 gives awesome views, but the scope would be way more expensive (I got this one on sale for about $1300; B1200 would have been well over $2000). Still, this scope blows your socks off in the naked eye on the eyepiece views. Just can't grab that with the imaging camera I'm using.

2. For lunar/planetary work I use a Meade 10" f/10 SCT mounted on an Atlas EQ-G equatorial mount.

3. The camera is an Orion Starshoot Solar System Color Imaging Camera IV. I got it because it says Solar System, and was dirt cheap at about $90 instead of the more often used imaging cameras, which are an order of magnitude more expensive. Ya get what ya pay for, but it turns out this does OK for initial playing around. It is, of course, a CCD camera. To be so cheap, the imaging chip is tiny. The only way to get a useful image on the chip is to build in a tiny lens. The lens has a focal length of 5mm. This means WAY too much magnification to come to focus because of A. the sweet spot for focusing is almost nonexistent, and B. it way overdrives the image for the ability of the atmosphere and the telescope to deal with. Live and learn. After weeks of fooling around, and NEVER getting a good focus with any of my scopes, I realized that the magnification was overdriving the ability of the system to cope. To cope, I first used an f/6.3 reducer I have for the SCT at the visual back to get bigger fields of view. That did a great job on easing the focuser issue and I actually got some pretty nice shots of the first quarter moon in daylight on January 2 through the 10" SCT. I was trying some solar as well with a white light full aperture filter, but the filter shims got soft in the heat and the filter hit the pavement and became a billion pieces of glass shards. Still, the f/6.3 reducer/corrector doesn't help the other three scopes. So, as a brain storm, I did a Google search on "focal reducer" and found two different screw in filters to drop the magnification in half. Orion's was/is on back order, but our host Astronomics had the Antares of Canada version, same as Orion's, except Astronomics charges $15 instead of Orion's $30. It came on January 5, and WOW what difference with the solar scope.

4. The video capture software itself requires setting more than ten different parameters, with NO guidance from the camera manufacturer or the software publishers. I've been alternating among three different packages (AMCap from Orion with the camera, SharpCap, and FireCapture), all free ware. But the settings like exposure, brightness, gamma, contrast, saturation, sharpness, and more have ranges of values in the hundreds, and just a few counts wrong can make the image useless, and focusing, too, is WAY off from the eyepiece view so focusing must be done through the laptop screen, and what is on the screen is only a rough approximation of digital data storage. A half inch of focuser travel in or out can make the image disappear. Sheesh. So I started a systematic study of settings and have found some good numbers to work with. Oh, and the optimal values change during the day as the sun and moon change elevation in the atmosphere. Your eyeball at the eyepiece sees none of this; we have a marvelous natural signal processing capability in our brains!

5. After I got the Antares reducer and went back to the solar scope four days later, I finally started to have some good luck on solar. It is an interesting artifact of the Starshoot that you can get the prominences by setting the Gamma at less than 10%, and sunspots at greater than 90%. Learned THAT the hard way. I'll give two YouTube links at the bottom to see the actual videos of prominences and sunspots, but I had to send this single stack of the sun setting behind Sombrero Peak, 1.4 miles from my back yard, with the gamma set for prominences. Couldn't get the sunspot setting worked out with the sun so low; turned out trashy but note the cactus in the prominence setting run! I'll have to learn how to rotate the image to get the orientation right and not lose the perspective.

Solar Disk: Capture 1_8_2012 4_42_02 PM_GREAT.avi - YouTube

Solar Prominences: Capture 1_8_2012 4_38_46 PM.avi - YouTube

[Montana]

Thanks for the report, a very beautiful picture too

Alexandra

[Skylook123]

Thank you, Alexandria. It was extremely exciting to learn how to choose to look either at the solar disk, or the prominences, by varying the gamma in the video capture. And even more so when the near field landscape stood out so profoundly in the foreground. I forgot to rotate the camera in the eyepiece to get the image upright, though.

It is such a learning curve!

[Merlin66]

JIm,

Sounds like your having fun!

I'm interested in your comment:

I was trying some solar as well with a white light full aperture filter, but the filter shims got soft in the heat and the filter hit the pavement and became a billion pieces of glass shards.

Can you explain further? Which filter hit the pavement? The full aperture filter or some other?

Which telescope were you using at the time - I assume the 10"

[Skylook123]

Correct, Merlin, it was the 10" SCT with a 12 year old Orion full aperture glass solar filter. The glue on the shims gave way when I put the Atlas mount into Park. As it moved from pointing at the sun to the Home position, the filter slipped off the shims and the old glue and crashed onto the brick observing pad. At it's old age, I had about 1/4 of the surface coating patched with black magic marker, so it was deteriorating. Still, it was the white light large aperture asset. I'm building a Baader film replacement.

Ironically, the identical thing happened about six months ago with my 90mm ShortTube. Same age filter, same thing happened. I've already built a replacement from Baader film for that one.

[kenmyers]

Wow! These are brilliant.

Look at those proms!! blimey!

[Skylook123]

Thanks, Ken. Very easy to visualize the whole panorama in the eyepiece, but with a $90 web cam, it takes learning new tricks to get the features to come out. Shows how remarkable our own eyes are for their dynamic range.

Here is a full solar disk taken two minutes prior to the prominence image, just prior to contact with Sombrero Peak. The only difference between the white disk with the promenences, and the solar disk with the details, is the gamma has been set during the capture to 10% for flares, 90% for disk features. Pretty easy to slide the gamma bar on screen and capture another 10 seconds of video. Then, in processing, I took the advice I received on the Cloudy Nights forum and investigated using manual wavelet settings in AviStack. That had little effect on the prominence stack, but did seem to "wake up" details in the solar disk image.

To repeat a note about my interest, it's purely in using the camera real time for public education so that there can be a common share of impressions. I do outreach up to ten times a month, and the public benefit to using real time display is intriguing. Using the cheap camera means that my setup is not as complicated as some I've seen.

Here was the sun 2 minutes prior to it passing behind the Peak:

[Zul]

Very nice