Monday, February 11, 2013

First light with PST/SmartEQ combo, also Orion SSAG working as imager


Well since fixing the iOptron SmartEQ mount, I finally got to put it through it's paces for solar imaging. I must  say that I am extremely impressed with the tracking ability of this little mount. It is almost like the PST and SmartEQ were a match made in heaven (pardon the pun). First off, I did a really lazy polar alignment. I took my compass on my iphone 4 and placed it in the accessory tray. Found what it said was magnetic north and I guestimated what I thought should be 6 degrees deviation for true north. That's it! Nothing more. Knowing that the goto would be off but figuring it would probably be in the neighborhood, I did a goto slew to the sun. It was only a couple degrees off. I won't say perfect tracking, but only the slightest corrections were needed to keep the sun centered, and they really were infrequent. Another plus was I accidentally kicked the tripod leg knocking the whole mount from it's original position by several inches. I just wiggled the mount until the sun was in the finder again and fine tuned centering the sun. Another several hours of worry free tracking. I never got this kind of tracking accuracy when using the NexStar 8 mount for solar observing, even when I synced on the sun.

I know that it goes without saying, but viewing the sun on a stable mount was so much more pleasant. Using the rickety photo tripod that I had, it was maddening to attempt focus. I finally got a razor sharp focus for the first time since I purchased the PST. Everything seemed to be going my way so I thought I would pop in the DBK21 imager and have a go at some solar imaging. I quickly found out that it would not achieve focus. I tried to use a barrel extension tube but also did not have any luck with achieving focus. I popped in an Astrotech 2x short barlow and focus came. I was impressed with the fact that the images that I obtained with the PST were on par with my first images with the Lunt 60tha when using a color imager. Here is the best of the batch from yesterday's session. It is a composite of two images, one exposed for prominence detail and the other for disk detail. The huge prominence visible was really contrasty, even in the eyepiece. Not bad considering the detail that one can expect when using a color imager to do h-alpha imaging:


And another shot showing an active region:


Not bad at all, and certainly on par with the detail I obtained with my Lunt prior to getting a monochrome imager. That being said, I was spoiled to the detail that I obtained when using the mono imager and I just cannot go back to using a color imager for solar imaging. Quick little lesson to break down why mono imaging is better for H-alpha. Color imagers use what is known as a Bayer Matrix. Basically it is a microlens with red, green and blue elements. Red accounts for 25% of the matrix, and hydrogen alpha light is very narrow in wavelength, typically less than one angstrom for h-alpha scopes. This narrow slice of light is only in the red portion of the spectrum and as such, only is collected by red pixels in the Bayer Matrix. Since that is only 25%, you effectively decrease the resolution of the camera/imager by 75% when using it to image hydrogen alpha light. Monochrome imagers have the edge for h-alpha solar imaging because they can utilitze 100% of their pixels.

Since this is my "budget" solar rig, I really do not wish to plunk down $350+ for a mono imager again. I do have the Orion Starshoot Autoguider camera which has a 1/2 inch 1.3MP monochrome CMOS chip. This camera from Orion is meant to be used with the PHD software and is controlled with ASCOM drivers. Attempting to use this camera with other capture software is futile as it won't even be recognized by the software. I was doing some research and found out that the Orion SSAG camera is actually a QHY-5 camera in Orion clothes. As such, it should be possible to download the driver to make it work as an imager the same way that it's European cousins do. The problem with this is that I still intend to use it as an autoguider with PHD software and I do not wish to uninstall/reinstall different drivers everytime I wish to use the camera for a different purpose. I asked a few questions on Cloudy Nights, and was directed to the following page which has a free software download that will let you use the SSAG camera as an imaging camera without having to install new drivers. The name of the program is VideoSky 2011 by Emmanuel Rietch. It can be downloaded at the following link:




After installing this software I immediately had an issue with it detecting the SSAG imager. It would generate a "buffer overrun" error and shut down the program. Reading the site, it says that it isn't compatible with Windows 7 64bit (my imaging laptop's OS). I launched the program again in compatibility mode (winXP) and it fired right up. VideoSky detected the Orion SSAG camera and I was able to get an image.

I am on vacation all week so hopefully I will get a chance to image with this camera. Being monochrome and being a larger chip I hope to rectify my resolution issues. I am optimistic as there are many good examples of H-alpha imaging using the QHY-5 (this camera's european cousin). I will post up some images if I am successful, I am really hoping I don't have to shell out for another mono imager.


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