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Re: Mars 02/10/2020
We're certainly are spoilt downunder this spring for the planets. Jupiter and Saturn are at the zenith at dusk, Mars is up around 21:00 and passes the meridian around midnight at 50 degrees altitude in the North. The only downside is the seeing. We have a fair bit of jetstream at that time of year and it's hard to juggle pockets of steady air with holes in the clouds.?
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Re: Mars 02/10/2020
Hi Brian,
Yeah despite the best of our efforts, we are often at the mercy of things beyond our control. While we can work for clean optics, good collimation and focus, seeing and other factors can thwart our efforts. Showing that sometimes things work in our favor, I observed Mars last night under skies of variable, poor transparency. After observing some clusters and doubles in Cassiopeia with my C-11, I saw Mars rising higher through the muck. Since it was closest last night, I wanted to have a look before wrapping up the observing session. I was expecting the usual seeing-induce orange blob. Was I ever surprised. It was the best view of Mars I'ved had in a decade or more. I wished that I didn't have focal reducer in place, since higher powers seem to show more and more. With a 5mm Olivon eyepiece @ 350X the view wasn't very good. But this was expected since that eyepiece @ $78 shouldn't be expected to produce the excellent image provided by a multi-hundred dollar Nagler 11mm T6 @ ?160X. But the view was so sharp I tried a 9mm generic Plossl 195X which helped. But an old Celestron 7mm Orthoscopic gave the best view at 250X.?Among the visible features were Syrtis Major, Sytris Minor, Mare Cimerium and Mare Tyrrhenum. Ocasionally a tiny remnant of the south polar cap was suspected.? Since Michael has repaired my Gemini-1, and all seems to be functioning well, I'm inspired by last night's Mars experience to dust off my planetary imaging rig - ZWO ASI290MC OSC color video camera, ZWO ADC. I have until tomorrow night to put it all together. Early in the evening I'll touch up collimation while waiting for Mars to get high in the sky. Its circumstance are much better than Jupiter and Saturn residing low in my sky (about 23 degrees elevation). My C-11 has a 115mm refractor riding piggyback. That will serve as a finder of sorts to get Mars on the camera's tiny sensor.? That's my plan anyway. I'll see how this all works out. Best Regards, Russ |
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Re: Moving Ahead With My Losmandy G11 / Gemini-1
Michael, with Reflectix I've been pleased with the reduced heat input to the SCT OTA to keep dew at bay. I believe this also reduces tube currents inside. For those going portable this could be a big savings in battery size needed to last a night.
I mostly stay at home in my garden observing site. The light pollution is tolerable (Bortle 5), if the air isn't too moist. Often though what I call "thick air" is composed of very small droplets of fog beginning to form. These reflect a lot of light pollution. I have a lot of medical facilities within a mile and Walmart within two miles. When the air is dry, the Milky Way is visible down to about 30 degrees above the horizon. But being less than 5 miles from the Pacific Ocean makes dry air infrequent. Yet having just 25,000 population helps, especially since there are no big towns around. I'm not familiar with Gemini.net. What is it? Is that the Gemini User's Group? I need to hang out there more often. Seems like the Gemini and Losmandy groups are for similar interests. I did enjoy myself tonight looking at some open clusters in Cassiopeia. The transparency was variable fair to poor. But I discovered the seeing was quite good. I was able to use 250 to 350 power on Mars. Wow! Best I've seen in years. Since clouds and rain were predicted after midnight, I called it quits by 11 PM. Wednesday night is supposed to be clear. That gives me over a day to transition to planetary imaging. So off comes the focal reducer. Also my 2x Barlow gives a decent image scale at f/20. The tiny pixels of my ZWO ASI290MC help as well. I'll need to do some research. Even without the Barlow at f/10 the sampling is 0.21 arc-seconds per pixel. The resolution limit of the C-11 is around 0.4 arc-seconds.? What would you recommend, Michael? I'll for sure be using my ZWO ADC. My MacBook has a Windows 10 partition and a SSD for video capture. With Mars so bright it should allow for over 100 FPS. I have used FireCapture and AutoStakkert!-2 in the past. As you suggested I'll download AS!-3. I also have available SharpCap Pro. But seems like SharpCap's live stacking isn't the best. FireCapture + AS! + Registax has served me in the past. Biggest problem is collimation, focus and seeing.?I hope you get an opportunity for some Mars imaging with that C-14. What a beast that is. Jupiter and Saturn are too low in my sky fire up much enthusiasm. For identifying what is seen or photographed on Mars you might look at?the?. It seemed to do a good job?identifying what I saw tonight. Syrtis Major, Syrtis Minor, Mare Cimmerium and Mare Tyrrhenum were all as show on the profiler. Occasionally I glimpsed what could be the S. polar cap, almost gone. Here's a screen-shot of the profiler output: Well, I'd best move on to something else. Take care, Michael and all the rest of you! Best Regards, Russ |
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Re: Moving Ahead With My Losmandy G11 / Gemini-1
Beautiful. Coincidentally, I also discovered the benefits of reflective coating my scopes...really reduces the demand on the dew heater.? ? I got a whole roll of the reflective foam to cover new scopes and dew shields.?? When you connect your Gemini to your PC, you can download the settings (see the Advanced panel in Gemini.net).? Then you can upload the settings from the saved file if the settings get erased.?? Have fun. I heard from Andy Fischer in Missouri that Mars is closer than it will be for the next ~15 years. So this is a good time to image it if you can.? Andy got a great image...I'll have to see if I can figure out the surface features.? That's another fun challenge.?? Best, Michael On Mon, Oct 12, 2020, 7:57 PM <russmilt@...> wrote: Thanks, Michael. I'm getting it all back together. Replacement of SRAM and EPROM necessitates re-establishing all the previous setup information, such as geographic location. Tonight despite the sky being quite murky, it is time to set the safety limits. Also?SkySafari is now effectively controlling the mount. After 45 years of using star atlas and finder 'scope, I'm thoroughly enjoying the go-to experience of the Gemini-1. Here is what the C-11 looks like now with the OTA and dew shield covered with Reflectix. (See #317 in this ) |
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Re: Moving Ahead With My Losmandy G11 / Gemini-1
Thanks, Michael. I'm getting it all back together. Replacement of SRAM and EPROM necessitates re-establishing all the previous setup information, such as geographic location. Tonight despite the sky being quite murky, it is time to set the safety limits. Also?SkySafari is now effectively controlling the mount. After 45 years of using star atlas and finder 'scope, I'm thoroughly enjoying the go-to experience of the Gemini-1. Here is what the C-11 looks like now with the OTA and dew shield covered with Reflectix. (See #317 in this )
Someone said it looks like a satellite. It has really helped with heat management and dew prevention. After tonight's maintenance (safety limits,?SkySafari connection) I'm looking forward to Tuesday night for a predicted clearing. My goal is to finish examining Cassiopeia cluster sand moving on to explore Cepheus. I may even give a try on Mars. But that's a whole different setup and operating procedure. Having the 115mm refractor riding on top as a finder of sorts will be a real plus. Such is needed for the tiny sensor of my ZWO ASI290MC video camera. Yeah I had better do it - it will be many years before Mars is this close again.? Warm Regards, Russ |
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Re: Strange behavior of my G-11 Gemini-1
Masami, When convenient, open your Gemini-1 front cover, as if you were changing the battery. You will find 6 hexagonal "standoff" posts that support the front cover. Use a tool to unscrew those 6 posts, and put them in a container. Then the circuit board can be lifted up and out. Carefully inspect the inside of the metal case for evidence of moisture or other contamination. Carefully examine the front and back of the circuit board for discoloration.? If you see any, use isopropyl alcohol on a cotton swab ("Qtip") to scrub off the contamination.?? If you can get a head magnifier, like this one, it will help your look down into the black phone jacks at the copper wires, and also look into the inside view of the phone jacks wires.?? Sometimes these copper wires get corroded and make intermittent contact.? Again, clean out all corrosion you find and be careful not to bend the copper wires.? If any touch it will lead to false signals to the CPU.?? Also examine the side large handset connector. Remove the handset cable on both ends and inspect the socket and cable ends for corrosion.?? Now take apart the handset unit by removing the 2 screws in its back.? The top display diamond pad will remain attached by its ribbon cable so be careful not to break that.? Again look for corrosion on the top and bottom of the handset circuit board.? Clean any discoloration with a Qtip? and isopropyl alcohol. I think you will see something and will clean it out and your problems will be fixed.?? All the best, Michael After examining the main Gemini board, put the main unit back together. On Mon, Oct 12, 2020, 7:07 AM YAMADA masami <yamada@...> wrote: Michael, David and Brendan, |
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Re: Use of Warm-Start with G11/Gemini-1
This does work, Russ. I have a permanent pier set-up and usually loosen the clutches between sessions to load the OTA and then to balance. Just return the OTA to as close as you can to the CWD position, do a Warm Start and add a single star to synchronize the mount with the slightly different axis position. The previously-built model should work fine after this.?
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Regards, ? ? ?-Paul On Sun, Oct 11, 2020 at 08:23 PM, <russmilt@...> wrote: To facilitate mounting and unmounting my Celestron-11, I have been using a tip-in saddle as shown in this photo: |
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Re: Strange behavior of my G-11 Gemini-1
Very interesting John. (If you still have the faulty hand controller, I'd like to get a chance to repair it.? I have repaired at least one other hand unit.? Let me know if you still have it! ) Folks should know that corrosion of the copper traces on and in the circuit boards can occur.? The boards are not "conformal coated" with any kind of moisture repelling varnish.?? Corrosion is accelerated by 2 things:? ?a) Moisture (salt water is very corrosive) ?b) Voltage (DC voltage is a stronger corrosion driver than AC) So: Keep condensation and certainly rain or dew from dripping into your Gemini systems.? ?Keep the units well covered from any precipitation.?? Remove the DC power from your Gemini when you are done using it.? Even with the Gemini power switch off, the voltage is present on the board up to the switch traces. Better to just pull out the power input or be sure it is not putting out DC voltage (shut off the AC if using an AC/DC brick.) With those precautions, the Gemini-1 units should last many many years.? Gemini-2 units may be better sealed up, but not having one I can't say for sure.?? All the best, Michael On Sun, Oct 11, 2020, 7:27 PM John Schaub <bsa1313@...> wrote:
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Russell Milton
Michael Herman
Paul Kanevsky