robrj
Member
Posts: 248
home town/country: Escondido, CA
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Post by robrj on May 5, 2018 19:25:17 GMT
I upgraded the manual mount on my Skywatcher 12" Dob so it had a goto/tracking feature. I had to order it from Canada as they don't sell the base-only upgrade kit in the US. I've been using it the last couple of times out and have been getting decent results at the native focal length/ratio (f/4.9). I'd like to try it with my 0.7x reducer but I have to get the spacing down. It didn't work with the barlow method I used for the Ultrastar/Lodestar cameras. I got the mount working with Sharpcap and Stellarium/StellariumScope so now it can plate solve as well to center the image. It just uses the Celestron Driver that I had already set up with my AVX and Nexstar 130SLT. So I just plugged it in and it worked. Here are some of the images I took with it. You can see an original (which is how it came off the scope) and after it was processed with Startools. From the Jupiter image forward is with the goto base: www.astrobin.com/users/Robrj/collections/173/
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Post by howie1 on May 6, 2018 1:36:46 GMT
Did you mean eq platform or just simple goto tracking in alt az. I ask as the "home" photo on that link shows there's some kind of double platform base under the dob base. Beaut images BTW!
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robrj
Member
Posts: 248
home town/country: Escondido, CA
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Post by robrj on May 6, 2018 2:00:25 GMT
No. It's a goto base. I had an equatorial base but it was kind of a pain to use with a camera.
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Deleted
Deleted Member
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Post by Deleted on May 6, 2018 10:30:07 GMT
Those are great images Rob. I must get my SW 12" goto Dob out again. I havent used it since last Dec. Have been trying to get the SCT's images somewhere near the quality of the newts with very little success. I used an Altair 2" 0.6 FR with the ZWO 294 and you informed me that the f/ratio was 3.9 when you plugged it into astronomy.net.That was about .8 FR. I am pretty happy using the Altair on newts given they are meant for refractors. Is your .7 FR one of those made specifically for newts? They are very expensive. Paul
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Post by davy on May 6, 2018 11:52:00 GMT
Always good to do upgrades,, my favourite pastime lol 😂
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robrj
Member
Posts: 248
home town/country: Escondido, CA
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Post by robrj on May 6, 2018 13:48:16 GMT
Is your .7 FR one of those made specifically for newts? They are very expensive. Paul It's just a 2" Antares lens.
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robrj
Member
Posts: 248
home town/country: Escondido, CA
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Post by robrj on May 11, 2018 0:19:40 GMT
I managed to get the focal reducer working. According to Agena Astro, the reducer needs to be 66mm from the chip. So I put together some spacers to get close. I calculated this one at f/3.3 for a total reduction of 0.67x. There is some heavy artifacts on the larger stars that looks like coma. Plus, I think the transparency was pretty poor. There was a lot of dew and the next morning there was a bunch of fog. It's pretty dim in this shot. I post processed a crop of the Antennae Galaxy and could barely make out the tails. I haven't posted that yet. NGC 4038 (32x8s) Gain 350 (click the image for a full screen shot).
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Post by Dragon Man on May 11, 2018 6:46:30 GMT
Looks good Rob. The tails are very hard to get.
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robrj
Member
Posts: 248
home town/country: Escondido, CA
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Post by robrj on May 11, 2018 14:11:10 GMT
Here's the cropped and stretched antennae galaxies. You can barely make out the tails:
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Post by ChrisV on May 11, 2018 14:42:19 GMT
That's looking pretty good with all that reduction
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robrj
Member
Posts: 248
home town/country: Escondido, CA
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Post by robrj on Jun 2, 2018 23:22:05 GMT
Here are some pictures of my setup. I put a Ram Mount ball on the side of the dob so I could add a stalk for my Windows tablet (Surface 3). This setup avoids any cordwrap problems while slewing as everything is contained on the scope.
I have a portable power unit (Ecoflow River) that I use to power the tablet, the mount and the hub. It's a 34ah lithium ion battery that has two 110vac, one 12vdc Cigarette lighter socket, two USB 5v 2a sockets, two USB quickcharge sockets, two USB C sockets, and two 12vdc barrel connectors which I use to provide direct DC to the hub and the camera's tec cooler. It also has a nice display that shows the number of hours left based on current usage, and the % of battery used. I mounted it on the base using some 3M locking tape on the side of the unit and the dob. The bottom just sits on the base. I took a chance on it with Indigogo when they were kickstarting it. It saved me a couple hundred dollars over what they're asking now, but it was still expensive. It greatly simplified my setup though.
Here you can see it sitting on the base. It sticks out a bit but it won't move. The locking tape holds really well.
Here's the hub. The camera and the mount are plugged into it and the cable goes into the tablet's USB 3.0 slot. It's held on with the locking tape (you can see some of it on the top of the hub where I used to mount a ComputeStick.
I just leave all the cables for the hub and the mount out there when I close it up for the night. I just have to carry out the tablet, the power unit and a small case which has the camera, coma corrector, the hub and some wires. I use the hub on my Orion so I'll probably get another one that I can leave out there.
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Post by davy on Jun 3, 2018 14:02:33 GMT
Very nice rob
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robrj
Member
Posts: 248
home town/country: Escondido, CA
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Post by robrj on Jun 12, 2018 21:45:23 GMT
I put some more images up (see the link in the first post).
For my latest, I used my Explore Scientific Coma Corrector with the camera. The first time out, I used it with the helical focuser. it wasn't bad but then I saw that you could remove that and add an adapter. My box has been packed away for about a year so I went back to it and sure enough, they included two adapters for connecting a camera. It was just a matter of removing one set screw from the helical focuser and it came off (the whole assembly unscrews). Then the adapter goes on in it's place. I used the M48x1" adapter. The extenders included with the ZWO ASI294MC Pro were enough to get me fairly close to the required spacing (55mm from the top of the CC without any adapters). The ZWO camera's sensor backspacing with it's t2 adapter is 17mm + a 16mm & a 21mm that was included with the camera gave me 54mm. The adapter included with the ES CC adds about 3mm so I'm at 57mm of backspacing. That's close enough for video astronomy. It increased the focal length of my scope from f/4.9 to f/5.1 (about 4%), which isn't huge. The advertised barlow effect is only 6% which I believe is one of the lowest you can get. I got some great shots with pretty clean stars across the field.
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Post by Dragon Man on Jun 13, 2018 5:47:24 GMT
New images look fantastic Rob! Pity I can't leave a thumbsup for you in there. I have to sign up and open an astrobin account and log in just to leave a thumbsup on images.
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