I have known since pretty early in my astrophotography adventure that the single most important component of your equipment is your mount. When I got my old, used, no-go-to CG5 mount, it was a huge step up for me. My AT8IN scope is really too heavy for the CG5, but taking steps to minimize the weight (like using a finder/guider) and begin careful about balance I could usually make it work and get reasonable results. However, I’ve long had a desire to get a better mount (along with a desire to get a cooled monochrome camera). Neither of those exactly fits with the “cheap astrophotography” theme, but then this hobby is known for growing on people and subconsciously inducing them to spend money. Back in November I became aware that Skywatcher USA was putting their EQ-6 mount on sale for a pretty good price. That’s one of the mounts I’ve been quite interested in for a long time, particularly because it is supported by the EQMOD project, an open-source mount control software project that greatly extends the capabilities of the mount. So I bit and ordered one right after Thanksgiving when Black Friday prices made the deal even better. It arrived a couple of days later. I was immediately impressed with how solid and massive and finished the EQ-6 looked. I unboxed it and put the mount head on the tripod, then hunkered down to finish the semester and get ready for Christmas. I didn’t have time to play with it until after Christmas, but I ordered an EQDIR cable for direct computer control, downloaded EQMOD and EQASCOM, and built a Windows 10 virtual machine from which to run everything. That last turned out to be a bust, because I couldn’t get the Meade DSI drivers to work under Windows 10, so I fell back to my Windows 7 virtual machine.
Finally I got a chance to try out the new mount the day after Christmas, with all my optical gear loaded on it (AT8IN with ST-80 refractor on top with the finder/guider on that and the Quantaray zoom lens bolted to the ST-80 rings). I got all the scopes and the Telrad aligned on a mountaintop through the living room window. This mount is pretty heavy to lug outside, but I can just manage with the counterweights removed. This optical stack also is a bit unwieldy. Anyway, I used a bullet level to set the mount’s home position, got polar aligned, and used Cartes du Ciel with the EQASCOM driver to start pointing the mount. It is wonderful to be able to do fast slews. I first went to Capella and it was within the field of view without doing any alignment. I slewed around and synched on 5 or six stars in various parts of the sky, then decided to do a Hα image of the Crab Nebula (the Moon was only 1 day past full). The tracking performance of the EQ-6, even prior to any periodic error training or correction, was much superior to what I’d been getting with the CG5. The resulting image is one of the sharpest I’ve ever taken, far superior to any of my prior Crab Nebula images.
I haven’t applied any PEC yet, but the guiding performance was far superior to what I’ve been seeing with my old CG-5. I have a lot to learn about how to best use this mount, but I’m really impressed so far. The main thing that went wrong on this image was the remote focuser failed (I suspect a loose linkage or bad connection, but haven't had time to troubleshoot yet).
Date: 26 Dec 2015
Subject: M1, Crab Nebula
Scope: AT8IN
Filter: Baader 7 nm Hα
Mount: EQ-6 (EQMOD)
Guiding: 9x50 mm finder/guider + DSI Ic + PHD 2.5.0.8 (Win 7 ASCOM)
Camera: DSI IIc, no chiller CCD -10 °C
Acquisition: Nebulosity 4.0.4, no dither
Exposure: 46x600 s
Stacking: Neb 4, bad pixel map, bias included, 33 flats, extract R channel, match histograms, square, trans+rot align, 40-60-tile stack, Catmull-Rom spline 2x resize
Processing: StarTools 1.4.305 + CS6 Astronomy Tools: Crop; Wipe; Develop: 84.75%; HDR: Optimize; Deconvolute: 3.5 pix; Track: Smoothness 88%, 4.5 pix; Levels; Astroframe. 
I used RGB data from 19 Dec 2012 and 21 Nov 2014, combined with Hα from 26 Dec 2015, to make this image. I played around with processing a bit. I healed out the stars from the Hα and combined the starless Hα with the R channel from the RGB, using a layer mask so it has the RGB data for the stars but Hα for the nebula. I used this to replace the RGB R channel, and boosted the R channel a bit using the channel mixer. I also used the Hα as luminosity for the whole image. This mostly was done to address the “blue star” problem I usually have with these images. I’ve still got a little of that close to the nebula but it’s better than before, and I have far more structure within the nebula than I’ve ever gotten with RGB alone.After posting this image and mentioning that I was using a new mount, several Astrobin users mentioned that I should give Sequence Generator Pro a try. I downloaded it and started the 45-day free trial the next day. The first night out with it, I seriously underestimated what it would take to set it up and couldn’t get anything to work right so I fell back to just taking an image using my old Nebulosity workflow. I imaged up to the meridian, where the mount’s meridian limit kicked in and stopped the tracking, then performed a meridian flip, reacquired, and restarted imaging. I set the EQASCOM timer to park the mount just after my target set and went to bed. I woke up in the morning to find the mount nicely parked. It is really nice not to have to worry about it bumping. I also decided to reconfigure my optical stack, so I just put the ST-80 on top of the AT8IN to use as a guide scope, which is what I originally intended when I bought the ST-80. I have the finder/guider and the Quantaray lens mounted on a separate dovetail bar so I can use them on the new mount too.
I decided I needed to work a bit harder to get Sequence Generator Pro up and running. I looked at the excellent “First Week with Sequence Generator Pro” tutorial (http://www.mainsequencesoftware.com/content/SGP-The%20First%20Week.pdf), which was a big help. One of the challenges to using SGP, which I thought might be a deal-breaker, is that it doesn’t support the Meade DSI cameras. However, I was able to work around that by using Nebulosity to control the camera and invoking the Nebulosity 4 ASCOM camera driver from within SGP. I also downloaded the free PlateSolve2 software from PlaneWave to use as a plate solver with SGP. I got the camera working, then got plate solving working, then tried a test automated meridian flip using SGP. This was simply amazing! You start by unparking the mount and then either giving the target coordinates to SGP or controlling a goto from Cartes du Ciel. SGP takes an image after reaching the target coordinates and by plate solving automatically aims the camera to within a fraction of an arc second of the target. It then starts your previously-calibrated guiding program (PHD2 in my case) and commences taking images. It will also use your motorized focuser to automatically focus using half-flux radii measured for multiple stars in your field of view, but I don’t have that working yet. When the mount reaches the meridian, SGP shuts off guiding, performs the meridian flip, takes an image and uses the plate solver to again center on your target to within a fraction of an arc second, turns the guider back on, and continues imaging for the preset time, then parks the mount. These are truly amazing capabilities, well worth the $100 cost, which I plan to pay as my free trial ends. Conditions on the night I got all this going were terrible, with lots of gusty wind. It was the kind of night I normally wouldn’t even have tried to image, but with this much more massive mount I was actually able to get decent data. So in case you can’t tell, I’m thrilled with the new mount.
