Sunday, March 11, 2012

frustrating session (Etobicoke)

Manuel and I had high hopes for observing and imaging. I was hoping to image Mars again. I also thought, by playing with exposure, we might be able to coax out the Martian moons. I considered trying to split some of the tight stars, naked eye, in Pleiades. And with his binoculars and my tripod adapter, I wanted to see if I could spot Garrard to the north. He wanted to trying the 9¼" on the DX, image Mars and maybe a DSO, and make sure the big SCT was collimated well. But, in the end, we were clouded out.


In the afternoon, I packed the netbook, my hand-made focusing mask, and some warm clothes. Headed to his place in the early evening.

First order of business: get some food. While we waited for the delivery, we chatted and watched a bit of NASA TV. One segment talked about the recent successful trials with Dextre on the satellite repair test platform, on orbit of course, at the International Space Station.

Showed him my Bahtinov focusing mask. I asked Manuel if he had all the required software for focusing. I recalled some discussion before about something missing. He said he did have everything now. He had all the software and hardware in place. I'm not sure if he's used it much. This will be helpful in the future during his imaging runs and should allow for results better than focusing by hand (like we did for Mars).

I asked if the DFK camera had cooling. He said it did. [ed: I'm still unclear. One report I read says it does not have active cooling.] Regardless, I had an eye to getting everything outside to begin cooling down. Manuel already had the Celestron optical tube assembly outside (stowed safely) to get to ambient temp. All the camera gear was still inside though.

I also wanted to know if he was using the DX's All-Star Polar Alignment process given that he could not see Polaris. He said he was. Good stuff. Austin Grant's DX review in (the Jan/Feb 2012) Astronomy Technology Today suggested this built-in procedure could allow one to forego a drift alignment. Still, I wanted to see Manuel go through the process. I wanted to observe the degree of accuracy he used. For example, I wanted to see if he'd use 2 alignment stars and 4 calibration stars.

After dinner, we continued the setup of the mount and telescope.

I also wanted to verify he was using accurate date, time, location information in the DX mount. The date and time was fine but the location had been set to Toronto. Not good enough. I programmed in his exact latitude and longitude. Advocating high accuracy at every stage.

We did not install the dew heating equipment. Didn't think it necessary.

When Manuel started to balance the telescope, I asked why he was doing this without the camera mounted. He said that it didn't weight that much. I said I thought it odd that he took such great care to balance the 'scope so early. I recommended he do it quickly at this stage but do it again after mounting all the accessories.

I also asked if he balanced the mount so to preload the drive. I'm not sure he knew what I was talking about. I'll have to explain this another time, that many imagers take care to predict where the mount will be pointing and then bias the balance slightly so that the gears are always loaded.

We discussed his cameras. For some reason, I thought he only had one now. Nope. He still has the QHY5: it is for guiding; still has the QHY9; for deep sky. And of course he has the Imaging Source DFK: for planetary.

We ran through the normal startup process for the mount. When it prompted for alignment stars, named of course, we didn't see obvious ones listed. Manuel forced the hand controller to offer more stars. After the two-star alignment, we slewed about. It was way off. We even checked the mount with his compass. It was fairly close. We rebooted and tried again. And then went through the All Star alignment. It only seemed to prompt for one calibration star. I wanted to do more but couldn't see a way to do that. Still, going through the process quickly was insightful. It really is a lot like drift aligning... Nevertheless, the mount was still off.

We did the process again. Manuel asked if I wanted the calibrated eyepiece. Yep. It will improve our accuracy.

I wanted to try again from scratch but I was having a hard time seeing stars. It was then we realised there was some thin cloud up high dimming things out...

Manuel copied the DX user manual to my netbook. I'll give it a thorough read at some point.

By 10:30 PM, we resigned. It was obvious that we were clouded out.

Never had a chance to check the collimation of the 9¼"... Never did split Pleiades. Never try for Garradd. Pity.

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