An Astrobin user asked me about using my ST-80 scope with DSI cameras and controlling it with a MacBook. I spent enough time replying that I thought I’d post my answer, edited a bit, here. A picture of my setup is shown here:
In the picture, I have the imaging camera mounted on the 9x50 guide scope and the guide camera on the ST-80 refractor, but normally I have the cameras swapped. It just depends on what field of view I'm shooting for.
Optically, I use either a Baader Fringe Killer or Baader UHC-S filter on the front of the DSI IIc imager, because neither the ST-80 nor the 9x50 is apochromatic. The filter helps suppress violet fringes, and the UHC-S (which I prefer of the two) also blocks IR and enables sharper focus. I sometimes also use an Antares 0.5x focal reducer threaded into the DSI IIc nosepiece (the filter goes on top of that); again this is to achieve the field of view I want. The reducer causes distortion around the edges of the field, but because the DSI IIc's chip is fairly small, it isn't too bad.
To connect the equipment, I use a powered USB-2 hub at the mount into which I plug both DSI cameras, and, until recently, a Shoestring GPUSB for controlling the mount. My mount is the very old CG-5, to which dual axis motors with a hand control have been added; you have to wire an ST-4 guide port jack into the hand control to connect the GPUSB, and instructions for doing so are on the Shoestring site. The hub connects to a 20 m active USB repeater cable (like the powered hub, I bought the cable at Monoprice.com), and I run the cable into my living room and connect it to my MacBook. I control the imaging DSI IIc with Nebulosity 3, and I control the DSI Ic guide camera with PHD2. Until recently, I used the Mac versions of everything.
A couple of months ago, after frying the mount controller (by plugging it into 12 V instead of the 6 V for which it was designed), I built a PicGoto Simplificado mount controller and have been using that rather than the GPUSB+ST-4+Dual Axis Controller. Because the PicGoto server is Windows software, that required me to start using VMWare and Windows 7. I had long resisted using VMWare/Windows, because it was slow to launch and just clunky, but in January I replaced the hard drive in my MacBook with an SSD. The SSD makes loading VMWare lightning fast, so now I can use VMWare with no pain. I currently control the mount using PicGoto server + Cartes du Ciel, and love it for how easy it makes finding targets and for how much more quickly I can slew the mount (30x sidereal, with the same motors as before, rather than the 8x I could get before I broke off the switch on my old hand control). I don't do long slews, because even 30x is pretty slow; I use a Telrad finder to find a bright star near my target, sync on that, then let the PicGoto + Cartes du Ciel find the target; this works to get the target in the DSI IIc's field of view every time (so far).
After experimenting a bit, I also switched to the Windows versions of Nebulosity 3 and PHD2, just because I find that to be simpler than switching back and forth between Mac OS and Windows. In addition, the Windows versions support many more camera choices (I suppose that's a moot point if your cameras are supported under MacOSX, as DSI's are), they connect to the DSIs more quickly than the Mac versions, and they enable ASCOM pulse guiding, which seems a bit more accurate (but that's just an impression; I don't have hard data to support it other than I think my images look better since I started using it).
Here’s one of the better images I’ve taken with this setup (prior to using the PicGoto Simplificado, so this image was all Mac-native):
Date: 8 Jun 2013
Subject: Markarian’s Chain
Scope: Orion ST80+Antares 0.5x telereducer
Filter: Baader Fringe Killer
Mount: CG-5 (Synta motors)
Guiding: 9x50 Finder/Guider + DSI Ic + PHD 1.14.2
Camera: DSI IIc (cooled at 2.25 A, 10.0 V, 12 °C)
Acquisition: Nebulosity 3.1.6
Exposure: 32 x 300 s
Stacking: Neb 3, bad pixel map, bias included, normalize first, trans+rot align, 1.5 SD stack.
Processing: StarTools 1.3 Crop; Wipe:Color & Brightness; Develop 84.95%; HDR:Optimize; Sharpen; Track; Color:Bottom 2.0, Top Full, Sat 600%; Denoise; Magic:Shrink 2 pix; Life:Heavy. CS6+Astronomy Tools increase star color; deep space, space NR; some clone stamp to remove an edge artifact; crop again; less crunchy more fuzzy; AstroFrame.
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